1971 CB350 . . . 40 year hibernation

[stl360+450]

I decided to have a look at the seat foam and pan today, while waiting for the replacement cam chain tensioner. Not pretty. The foam isn't too too bad at first glance, but there is a huge slash in the back of the foam. I think I could use some spray-on adhesive to remedy that. The four rear holes on the underside of the pan were definitely used as a mouse lair. I vacuumed as much as I could with the shop vac, but I'll need to fashion a "straw" to get all of it. The mice created a sizable cavity inside the foam that, once cleared, I think I fill with Tuff Stuff or equivalent. Might be smarter to buy new seat foam.

I have only worked on two CB350's, but both had some cracking in the seat pan. I assume this particular pan must be plagued by these cracks. This one is better than the one I saw previously and I drilled the ends of the cracks as a starter. I am contemplating pulling out the old flux welder again to have a go at adding a couple of strips of thin steel for reinforcement. I wonder how if I could weld in short spurts without removing the foam. Another reason to replace the foam, I guess.

 

[LongDistanceRider]

To do any welding at all the foam has to come off, it'll melt or catch fire. It's not glued on very well and comes off intact if you work it slowly.
You probably want to cut out where the mouse was living, urine and feces smell brings them back even years later. Fill with similar density foam.

 

[stl360+450]

To do any welding at all the foam has to come off, it'll melt or catch fire. It's not glued on very well and comes off intact if you work it slowly.
You probably want to cut out where the mouse was living, urine and feces smell brings them back even years later. Fill with similar density foam.

Thanks, Jim. I decided to order a new foam by S.C.I. I hadn't thought about the scent drawing more critters to the old nest, so thanks for pointing that out. I know I'll have a lot less heebie jeebies after completing removing that foam and starting fresh.

 

[LongDistanceRider]

Thanks, Jim. I decided to order a new foam by S.C.I. I hadn't thought about the scent drawing more critters to the old nest, so thanks for pointing that out. I know I'll have a lot less heebie jeebies after completing removing that foam and starting fresh.

Don't toss the old foam until you have the new stuff fitted.

 

[stl360+450]

Don't toss the old foam until you have the new stuff fitted.

Okay, but I'm going to need help with reinstallation if it comes to that. =) The aftermath of foam removal is shown below. This occurred before reading that last message.

I found that the narrow blade attachment for my shop vac was an effective scraper tool to remove foam remnants right down to the adhesive.

 

[LongDistanceRider]

Okay, but I'm going to need help with reinstallation if it comes to that. =) The aftermath of foam removal is shown below. This occurred before reading that last message.
I found that the narrow blade attachment for my shop vac was an effective scraper tool to remove foam remnants right down to the adhesive.

:lol::lol::lol: I think it's beyond salvaging now :lol:

 

[ancientdad]

:lol::lol::lol: I think it's beyond salvaging now :lol:

Yeah I'd say so, not enough glue to put all that back together

 

[GaryJames]

STL360,
My Seat pan was like yours, edge was rusted and split on the sides.
I bought one of these:
https://texavina.com/diy-metal-seat-pan-for-honda-cb350-k4-k5-1972-1973-sku-p1003/

and for the CB360 they have this:
https://texavina.com/diy-metal-seat-pan-for-honda-cb360-cb360t-twin-1974-1976-sku-p1002/

The manufacturing is a bit rough, it is made in several parts then welded together ( at least they ground off the weld lines ) instead of being a single sheet steel pressing.
Then powder coated. You can't normally see underneath anyway.
All the hinge brackets, lock mounting , rubber cushion mounts, document tray mounts were all in the right place. I was pleased the way it went together.
Hardest parts on rebuild was putting the chrome bottom edging back on... and stretching the cover to fit evenly. being vinyl a heat gun worked a treat.
I didn't use the weak aluminium studs ( which bend and break easily ) but found some small rose headed machine screws that fitted the chrome strip nicely and then nut and washer on the inside.


And some Foam shaped for the CB350 K3/K4 seat and a new cover off ebay with the Honda Logo on the back.
Cant recall where I got the seat foam but 4 into 1 has this at reasonable price:
https://4into1.com/seat-foam-honda-cb250k-cb350k-cb450k-cl350k/
The Cover was about US$40 from ebay.

I couldn't find Seat foam specially for your CB360 but the CB350 one may be close.... bit of trimming maybe

cheers

 

[stl360+450]

My Seat pan was like yours, edge was rusted and split on the sides.

Thanks for the links, Gary! I actually bought the cover earlier and then ordered the foam today after removing the old cover. I see that Texavina also makes a bare seat pan for the CB350 K3, so that would work. I think I'll have a go at saving the pan, but if I fail, this will be an excellent option.

Thanks for checking in on my project from time to time — I appreciate it.

 

[ballbearian]

That new foam looks great. I think you could fix the old pan pretty good. Adding a second layer of steel is good even if you lose one of the spikes. If you have a high and low amps setting, use low and a pretty slow wire speed. That worked better on the similar thin steel on the fenders I did. I just went slow and back and forth to tack my patch pieces down.

I think it'll turn out pretty nice.

 

[stl360+450]

That new foam looks great. I think you could fix the old pan pretty good. Adding a second layer of steel is good even if you lose one of the spikes. If you have a high and low amps setting, use low and a pretty slow wire speed. That worked better on the similar thin steel on the fenders I did. I just went slow and back and forth to tack my patch pieces down.

I think it'll turn out pretty nice.

I did my best. Out of respect to skilled welders everywhere, I will use the term splatter-welding for what I was up to this afternoon. I splatter-welded a piece of 16 gauge steel across each of the splits on the side walls of the seat pan. Each piece was about 1" by 3", although I cut the pieces by eye. I held them in place with a vice grip until the splatter-welds were built up enough to hold the piece in place and then added more splatter-weld in the freshly exposed areas. In theory, I believe these vertically oriented reinforcements should do a good job to prevent the seat from bending by increasing the area moment of inertia at the high stress points (where the original cracks formed). Hopefully the splatter-welds will hold up.

I also splatter-welded the portion of these side wall cracks on the horizontal face of the pan, including filling the drilled holes I made at the end of each crack. After the plates were splatter-welded, I added some more splatter-weld on the outsides to try to close up the cracks in the original pan. I call this a success simply because I never burned through the pan.

Finally, there were very short cracks that had started to form around the hole in the center of the pan, located along the line between the two cracks in the side walls of the pan. I believe this seat pan was poorly designed and I'm curious whether this design is particularly susceptible to passenger loading or if it would crack under normal operation with a single rider. Anyways, I drilled the ends of each short crack and did my best to splatter-weld the cracks and drilled holes from above and below.

Good call on removing foam prior to splatter-welding, Jim. As it is, some small remnants caught fire and I had to blow them out a few times. This is one of the reasons I only splatter-weld outdoors.

 

[ballbearian]

LOL. I did that many times until I figured out, that's what happens when you hold the tip too far away. Clip the wire off right next to the nozzle and hold the tip against the work.
Maybe it will hold, with all the weld you just stuck to the surfaces, but you din't really get much penetration, ie, melting into the pieces you want to join.
Good place to practice cause no one will see that.

Did you turn down the wire feed speed?

 

[stl360+450]

LOL. I did that many times until I figured out, that's what happens when you hold the tip too far away. Clip the wire off right next to the nozzle and hold the tip against the work.
Maybe it will hold, with all the weld you just stuck to the surfaces, but you din't really get much penetration, ie, melting into the pieces you want to join.
Good place to practice cause no one will see that.

Did you turn down the wire feed speed?

I had limited time today, but should be able to spend a little more time going around the edges of the small plates. I'll try to keep the lead wires short and get the heat into both pieces to make a real weld. I know a few small places looked okay to me on each plate, but the overall results were not so hot. Thanks for the encouragement.

Mine has low/high (maybe min/max) and I used the lower setting. Wire feed goes up to 10 and I was using 2.

I was just looking at the pan again. It feels very rigid now, whereas I could easily flex it bare-handed before the "repair". It's a fair concern about whether one or both of those plates might just pop off at some point down the road, so I'll have another go while waiting for the foam.

 

[ballbearian]

I had limited time today, but should be able to spend a little more time going around the edges of the small plates. I'll try to keep the lead wires short and get the heat into both pieces to make a real weld. I know a few small places looked okay to me on each plate, but the overall results were not so hot. Thanks for the encouragement.

Mine has low/high (maybe min/max) and I used the lower setting. Wire feed goes up to 10 and I was using 2.

I was just looking at the pan again. It feels very rigid now, whereas I could easily flex it bare-handed before the "repair". It's a fair concern about whether one or both of those plates might just pop off at some point down the road, so I'll have another go while waiting for the foam.

You have to clip off the flux core wire as short as possible to keep the gun tip in contact with the work pieces.

You can always drill and pop rivet the plates as extra insurance they won't pop off. I used to do pop rivets for all this kind of stuff before I got a welder.
You got this.
A functional repair plus gained experience = a worthy endeavor.

 

[DavidR8]

Welding takes a fair bit of practice. I'm no pro but can manage to lay down a decent bead every once in a while. :lol:

 

[ancientdad]

I've barely done any arc welding and it was only with a stick welder, never anything good. I used to be able to gas weld pretty well, but I haven't used torches in about 30 years so I'm quite sure my skills have eroded badly. I have my father's old full-sized set of tanks but the oxygen regulator is shot, and with so little need for it I've not bothered to replace it and get the tanks refilled, the money would just sit and go unused. But it's damn sure handy to have something around to weld with when the need arises.

 

[stl360+450]

Here's what I've done to remedy the sketchy welds achieved earlier. I drilled five holes (corners + center) through the outside of the seat pan into the backing plate, but not through (except on the two holes where it went through). This gave me a shallow hole to feed a bunch of wire into and get everything glowing nice and bright to create a decent bond between the pan and the backing plate. I did this on both sides, but I'll only show one side below (the better one!). I think this should solidify the plates enough to build the seat without fear of the plates coming off or the seat cracking again.

Welding takes a fair bit of practice. I'm no pro but can manage to lay down a decent bead every once in a while. :lol:

I aspire to reach the level of an occasional decent bead. I'm finding thin pieces like the seat pan especially challenging, whereas the center stand went a little more smoothly.

I've barely done any arc welding and it was only with a stick welder, never anything good. I used to be able to gas weld pretty well, but I haven't used torches in about 30 years so I'm quite sure my skills have eroded badly. I have my father's old full-sized set of tanks but the oxygen regulator is shot, and with so little need for it I've not bothered to replace it and get the tanks refilled, the money would just sit and go unused. But it's damn sure handy to have something around to weld with when the need arises.

Agreed. I've now "welded" on the frame, center stand, exhaust, and seat pan with this project. Eventually I hope to develop a feel for the flux welder. I feel like I would probably do better with a torch and a rod, but the flux welder just makes more sense for my workspace. I don't really want to have tanks of flammable gases around all the time.

 

[stl360+450]

The 2fastmoto cam chain tensioner arrived today, so I should be able to resume the motor build soon. It looks good to me.

 

[ancientdad]

Well, it does look good, like the real thing. Good to know, I've always been a bit skeptical of them because of the many cheesy accessories I've seen them showing on eBay. I wonder if they offer the more complicated versions of the guides and rollers for the DOHC 450? I'll have to look.

 

[ballbearian]

Well, it does look good, like the real thing. Good to know, I've always been a bit skeptical of them because of the many cheesy accessories I've seen them showing on eBay. I wonder if they offer the more complicated versions of the guides and rollers for the DOHC 450? I'll have to look.

They do look pretty good. Overall, I've done Ok with 2fast, About the same with 4into 1 on many things. Maybe just depends on the item, or I've gotten lucky.

 

[ballbearian]

Here's what I've done to remedy the sketchy welds achieved earlier. I drilled five holes (corners + center) through the outside of the seat pan into the backing plate, but not through (except on the two holes where it went through). This gave me a shallow hole to feed a bunch of wire into and get everything glowing nice and bright to create a decent bond between the pan and the backing plate. I did this on both sides, but I'll only show one side below (the better one!). I think this should solidify the plates enough to build the seat without fear of the plates coming off or the seat cracking again.







I aspire to reach the level of an occasional decent bead. I'm finding thin pieces like the seat pan especially challenging, whereas the center stand went a little more smoothly.



Agreed. I've now "welded" on the frame, center stand, exhaust, and seat pan with this project. Eventually I hope to develop a feel for the flux welder. I feel like I would probably do better with a torch and a rod, but the flux welder just makes more sense for my workspace. I don't really want to have tanks of flammable gases around all the time.

A "spot weld in a hole" worked good for me on fender patch/reinforcements too.

I think the flux welders are hard due to the fat tip, makes it hard to see and a tendency to pull the tip back further, which just makes that splatter way worse and loss of penetration.

 

[stl360+450]

A "spot weld in a hole" worked good for me on fender patch/reinforcements too.

My thinking was that this type of spot weld is one step up from a pop rivet and should hold up well. The seat pan feels very solid at this point and once I paint it, hopefully it will look a lot better, too.

 

[ballbearian]

My thinking was that this type of spot weld is one step up from a pop rivet and should hold up well. The seat pan feels very solid at this point and once I paint it, hopefully it will look a lot better, too.

Looks solid. Now that the sides are strong, the bottom won't crack anymore. I just threw poprivets out because you could get away with it there but not on fenders for looks.

 

[stl360+450]

Looks solid. Now that the sides are strong, the bottom won't crack anymore. I just threw poprivets out because you could get away with it there but not on fenders for looks.

For sure — pop rivets would totally work. I actually bought my pop rivet tool about five or six years ago while working on another rotted seat pan. Many of the little triangular spikes were broken so I pop-riveted some spike strips on the inside of the pan to replace them. Pop rivets were my favorite thing for a while after, but now I need to keep going to school on the flux welding so decided to stick with it.

 

[stl360+450]

So, now I am back to where I was a few days ago. Tensioner and base gasket are installed and I'm ready to add the cylinders.

There are two rubber seals/o-rings/collars in the gasket set that I have not identified and I'd like to figure out what they are and where they go, if they go anywhere at all. I've looked through the K3 parts manual for the CB350 a couple of times and have yet to find them. They are similar to seals I've seen on other motors that would go around a cylinder stud, but, looking at the parts manual, I only see two dowel pins between the case and cylinders and two more between the cylinders and the head. I don't recall running into these during the disassembly of either motor, either.

Does anyone know what these are?

 

[ancientdad]

I had to double-check the 350 as it's been decades since I've rebuilt one, but there don't seem to be any o-rings between cylinder and head. Those are often added to kits mistakenly because the DOHC 450 uses them around the dowel pins on the 2 right hand cylinder studs in the head gasket, so not for you.

 

[stl360+450]

I had to double-check the 350 as it's been decades since I've rebuilt one, but there don't seem to be any o-rings between cylinder and head. Those are often added to kits mistakenly because the DOHC 450 uses them around the dowel pins on the 2 right hand cylinder studs in the head gasket, so not for you.

Thanks, Tom. I wanted to check just in case I was missing something. I thought it might be possible that there was a change somewhere along the line.

 

[stl360+450]

Between the two motors I disassembled there was one camshaft spacer. The spacer was on motor #2 with the totally fried top end and I am not using any top end components from that motor. The spacer I found appears to have been a 0.2mm spacer, but it is shot. There is actually a hole in the ring.

The cam I am using came from motor #1, but I found no spacer in that motor. It was also clear from the presence of replacement fasteners that someone had that top end apart in the past. The FSM describes standard side clearance as 0.2—0.6 mm (0.008—0.024 in) and recommends a 0.2 mm shim when the side clearance exceeds 1.0 mm (0.04 in). I don't think I am set up to measure side clearance with any confidence. From the factory, would it be possible that no shim was installed or would a 0.1 mm shim be typical? I guess I'm not sure what to do here.

 

[LongDistanceRider]

Looks like thin gaskets were used for the cam bearings which degreased the free play to zero and burnt the shim up.
Checking the free play is quite simple. Set the cam in place, add the gasket you're going to use and put the cam bearing in torqued to spec. Push the cam back and forth a couple times and then push to the points side. Stick a feeler gauge between the right bearing housing and the cam, try different ones until you get one that just barely slips in, that's your clearance/free play.

 

[stl360+450]

Looks like thin gaskets were used for the cam bearings which degreased the free play to zero and burnt the shim up.
Checking the free play is quite simple. Set the cam in place, add the gasket you're going to use and put the cam bearing in torqued to spec. Push the cam back and forth a couple times and then push to the points side. Stick a feeler gauge between the right bearing housing and the cam, try different ones until you get one that just barely slips in, that's your clearance/free play.

Thanks, Jim. The manual description involved a dial indicator, which is what had be worried. I can do what you described. Do I understand correctly that I could even do this with all of the pieces off the motor? In particular, I don't need to have the sprocket and chain installed?

 

[LongDistanceRider]

Thanks, Jim. The manual description involved a dial indicator, which is what had be worried. I can do what you described. Do I understand correctly that I could even do this with all of the pieces off the motor? In particular, I don't need to have the sprocket and chain installed?

All you need is the cam, cam carrier, both bearing ends and the gasket you're going to use. The thickness of the gasket makes a difference.
Dial indicator is best but the feeler gauge will do the job.

 

[stl360+450]

I set up the cam case on my work table to measure the camshaft side clearance. I found the clearance to be about 0.025 in (0.635 mm), which is slightly outside the standard range 0.008—0.024 in (0.2—0.6 mm). I ordered a 0.1 mm spacer last night and by my reckoning that will put the clearance in the acceptable range, albeit on the high side. The FSM notes that when the side clearance exceeds 0.04 in (1.0 mm) a 0.2 mm spacer should be used, so I think 0.1 mm must be the recommended spacer for my situation. I am including pictures to make sure I measured the correct gap.

 

[LongDistanceRider]

Sounds good, pretty simple once you do it.

 

[stl360+450]

The goal for today was cam timing. I started by installing the Rick's high-output rotor and stator. I actually woke up last night wondering where I had stashed the key for the rotor, but I had it in a Ziploc bag with the rotor bolt. I used a slap wrench to torque the stator bolt and moved on to the stator. I had the side covers vapor blasted and I found that the panhead screws for the stator were not going in very easily. I thought this might have been caused by left over media from the the vapor blasting, so I used a tap to clean up the threads and then installed the stator, also from Rick's. The rubber seal for the stator wires was really difficult to install, but once I got it into the slot I was happy with how tightly it fit — I don't expect it to leak. The stator does not have an explicit timing mark, but the orientation of the stator is exactly the same as the OEM stator in the middle of one of the winding coils. I also used a center punch to make a timing mark on the cover itself as a backup.

I rotated the crank to the LT mark and, with some fiddling, got the sprocket in position to install the cam. The L mark on the sprocket should be visible from the left-side of the motor and the line underneath the L should be horizontal and level with the top of the cam case. With a little more fiddling (the kind without a stringed instrument), I got the cam into position. It took me quite a while to be satisfied that the cam and sprocket were properly positioned. When I wasn't happy with the orientation, I would "disengage" the cam from the sprocket so it would sit a little lower in the case. This allowed me to move the chain forward/backward at the bottom of the chain, rather than try to move the chain over the sprocket itself tooth by tooth. The latter method had worked for me on other motors, but there wasn't enough room to do that here. With the crank, cam, and sprocket all lined up properly, I installed the cam bearing covers without fasteners to keep the cam chain under some tension and make it easier to turn the cam via the crank. At this point I put in the fully threaded sprocket bolt (near the L) with blue Loctite, then rotated the crank until I could install the shouldered cam sprocket bolt, again with blue Loctite. I've seen some threads where those bolts either sheared or came out and I don't want this thread to join the list (knock on wood). I finished for the day by installing the camshaft seal with a tiny amount of Hondabond applied on the outer radius.

I did tighten up the mounting screws on the left-hand cam bearing, but not on the right. Once the camshaft spacer arrives, I will install it, check the side clearance again, and hopefully finish up the top end of the motor.

 

[stl360+450]

A small task for this afternoon involved an attempt to fix the broken neutral switch that ballbearian had noticed earlier. I also purchased a used one on eBay, but wanted to see if I could salvage the old unit. My plan was to drill a small hole in the flat copper end where the old contact pad had broken off and then put a big ball of solder on the front side of that hole. A smaller ball of solder on the backside will help ensure that the solder stays put. Once I accomplished all of that, I used a file to flatten the solder contact pad.

 

[stl360+450]

And some Foam shaped for the CB350 K3/K4 seat and a new cover off ebay with the Honda Logo on the back.
Cant recall where I got the seat foam but 4 into 1 has this at reasonable price:
https://4into1.com/seat-foam-honda-cb250k-cb350k-cb450k-cl350k/

Cheers, Gary, and thanks again for your help. I received a new foam and seat cover. The pan has been welded, cleaned, and painted. I'm at the step of gluing the foam on the pan and was wondering if you have any tips. I was thinking about wrapping it up with painter's tape to hold the sides of the foam against the seat pan while the glue dries. Did you need to do anything like that with your foam?

Since my CB350 came with high pipes, I'm planning to use brads on the seat instead of the original chrome strips, mimicking the CL350 seat. I ordered some rubber sheet metal trim to replace the worn out trim under the original cover. Still waiting on that to arrive.

 

[ballbearian]

A lot going on in your garage. Nice contact repair, I bet that will work fine. I'd be chicken to glue the foam until I'd test fit the cover on the seat. Does the foam fit the pan pretty nice?

 

[ancientdad]

A small task for this afternoon involved an attempt to fix the broken neutral switch that ballbearian had noticed earlier. I also purchased a used one on eBay, but wanted to see if I could salvage the old unit. My plan was to drill a small hole in the flat copper end where the old contact pad had broken off and then put a big ball of solder on the front side of that hole. A smaller ball of solder on the backside will help ensure that the solder stays put. Once I accomplished all of that, I used a file to flatten the solder contact pad.

Looks like you built in some wear thickness too, nice job.

 

[LongDistanceRider]

Nice switch repair and good looking assembly of the engine.

 

[stl360+450]

A lot going on in your garage. Nice contact repair, I bet that will work fine. I'd be chicken to glue the foam until I'd test fit the cover on the seat. Does the foam fit the pan pretty nice?

The foam does fit pretty well. It has some indentations that correspond to different high/low spots on the pan and the overall length, width, and contour seem good. The only thing that is hard to judge is how well the pan sits into the foam. In particular, I can't remember how close the foam should come to the edge of the pan around the sides and back. Test fitting the cover is a good idea — I haven't done that yet.

Looks like you built in some wear thickness too, nice job.

Thanks, Tom. I wanted to put a good glob of solder on there and it ended up even larger than what I intended, but, yeah, hopefully it will work and last for a while.

Nice switch repair and good looking assembly of the engine.

Thanks, Jim. It's super helpful to have three trusted sets of eyes on the work at this point of the build, especially since this is my first time building a CB350.

 

[GaryJames]

Stl360,
regarding the foam, I am sad to say I don’t think I glued it at all.
The vinyl cover was a really tight fit and I had to use a heat gun to stretch it carefully, bit by bit.
Time will tell if the foam is stable but I just went down to the garage to check it now and it feels really firm.
However some miles sitting on it may be a different story and I may have to take it apart and glue it.
cheers

ps, I repaired my neutral switch as the contact pad had worn away. I used Silver Solder to make the same blob you have. My reasonings is Silver Solder is a lot harder than soft solder and should last a fair while.
easily enough done with a pressure can butane flame torch for the higher temperature required.
cheers

 

[stl360+450]

Stl360,
regarding the foam, I am sad to say I don’t think I glued it at all.
The vinyl cover was a really tight fit and I had to use a heat gun to stretch it carefully, bit by bit.
Time will tell if the foam is stable but I just went down to the garage to check it now and it feels really firm.
However some miles sitting on it may be a different story and I may have to take it apart and glue it.
cheers

ps, I repaired my neutral switch as the contact pad had worn away. I used Silver Solder to make the same blob you have. My reasonings is Silver Solder is a lot harder than soft solder and should last a fair while.
easily enough done with a pressure can butane flame torch for the higher temperature required.
cheers

Thanks for the quick reply, Gary. I probably don't need to worry too much about gluing the foam along the sides then. After I test fit the new cover, I'll plan to use some adhesive spray in a few strategic areas to help keep the foam in place on the pan.

Silver solder is a better solution for the neutral switch. I'll upgrade my repair as I think I've got everything required on hand. Thanks for the suggestion!

 

[stl360+450]

The silver solder upgrade of the neutral switch is complete and I think that was a really good idea — thanks again, Gary!

I also took some pictures of the seat foam to show how it fits. This is an SCI foam advertised for CB350 K1—K5. It seems to fit very well in the back and along the sides, but the front appears a little wonky to me. Maybe when it's pressed into the foam the fit will be similar to the original. I also did a test fitting of the cover on the foam and it felt like it would be tight. I'll have to heat up the cover a bit when I try it again, but I'm not opposed to shaving some foam here and there to get a better fit if it comes to that.

 

[LongDistanceRider]

Foam looks good. Here's a couple of pictures of my seat before the cover

 

[ballbearian]

No, don't shave the foam. That looks great. Another trick, is to use a thin plastic bag over the foam to help the cover slide over the foam. The very front won't matter because it will be next to the gas tank. I've also seen a thin edging over the metal edge on some seats, but a couple strips of duct tape would probably do the trick too. It looks really nice and so does your pan.

I've never glued the foam down, never thought it needed and better, if you want to adjust it or add some extra somewhere. Once the cover is on, it's not going anywhere.

 

[stl360+450]

I received some sheet metal trim in the mail today, which allowed me to install the seat cover and foam on the pan. I followed Gary's example and ballbearian's advice to not glue the foam to the pan and was able to install the cover without shaving he foam. It took a while and I also borrowed Gary's trick of using a heat gun to help stretch the cover. I plan to finish the seat with buttons (brads) similar to what one finds on the CL seats of the era. I pulled some buttons from an old CL seat I have laying around, but I will try to source new/replacement buttons. I'm guessing I will have to create evenly spaced holes in the pan for the buttons, since this pan was formerly fitted with chrome trim. I assume the holes for the trim on a CB seat are not spaced the same as the holes for the buttons on a CL seat.

I also received the 0.1 mm camshaft spacer today and installed it as well. The side clearance seems good and I replaced the oil seal on the tachometer drive gear. A multi-bit screwdriver does a good job as a seal driver for little seals like this. The picture below shows a damaged tach cover that I took apart for the thrust washer. Turns out there was already one in the good cover, so now I have a spare.

I hope to install the rocker arms/shafts soon and finish the top end. I plan to apply some assembly lube to the lobes and followers and I think it would be a good idea to put a little clean oil under the lobes in the cam case to provide an oil bath. Is this a good idea? Also, if I do this and then install the frame over the motor (on its side), what will happen to the oil baths? I guess I would just squirt more oil in through the tappet covers once everything is upright?

 

[ancientdad]

The seat looks excellent, nice job.

I hope to install the rocker arms/shafts soon and finish the top end. I plan to apply some assembly lube to the lobes and followers and I think it would be a good idea to put a little clean oil under the lobes in the cam case to provide an oil bath. Is this a good idea? Also, if I do this and then install the frame over the motor (on its side), what will happen to the oil baths? I guess I would just squirt more oil in through the tappet covers once everything is upright?

Yes, if you lay the frame over the engine it will dump out any oil you put under the rocker arms, so just wait until you turn the frame and engine combo upright to do it through the valve cover openings. When my 450 was apart for the second time, I left the entire front end together and simply removed the top bridge to remove it from the frame during disassembly, then slipped it into the steering head of the frame and dropped the top bridge on with the nut on the stem to keep it in place going back together.

 

[stl360+450]

Thanks, Tom. I may still put some assembly lube on the lobes and followers beforehand. That stuff seems to stick pretty well, which, I guess, is part of its design.

 

[ancientdad]

Thanks, Tom. I may still put some assembly lube on the lobes and followers beforehand. That stuff seems to stick pretty well, which, I guess, is part of its design.

Certainly can't hurt.

 

[LongDistanceRider]

Here's the same seat buttons I used http://www.siriusconinc.com/products/detail/243