1974 CB360 Back From The Dead

74CB360

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Joined
Apr 2, 2024
Total Posts
37
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Location
Graham, NC
Starting this thread for my cb360 i picked up about a month ago. it had been sitting under a car port since 1979. i have all the registration cards from when it was bought new until it was last ridden. i have recently got it running again and ridden it for the first time. i will be documenting my progress on this thread. This is my first vintage Honda so any help or tips is appreciated! thanks.
 

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It looks like you have a solid bike to work with. You don't need to worry about posting thumbnail pics, we have the space for full-sized pics and it makes scrolling through them a little easier since each one doesn't have to be enlarged to see detail.
 
I'm glad to see the thread underway.

And thanks for the info about those NOS MAC mufflers from the SECA line. Do they have removable baffles?
 
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I'm glad to see the thread underway.

And thanks for the info about those NOS MAC mufflers from the SECA line. Do they have removable baffles?
no sir they do not, they are welded in. they sound good though, they are louder than stock but not obnoxious at all. i have to put rebuild kits in the carbs, after i do that i will post a video of it running. these mufflers can still be had on ebay. the guy i got mine from still had a couple sets.
 
It looks like you have a solid bike to work with. You don't need to worry about posting thumbnail pics, we have the space for full-sized pics and it makes scrolling through them a little easier since each one doesn't have to be enlarged to see detail.
good to know, thank you!
 
no sir they do not, they are welded in. they sound good though, they are louder than stock but not obnoxious at all. i have to put rebuild kits in the carbs, after i do that i will post a video of it running. these mufflers can still be had on ebay. the guy i got mine from still had a couple sets.
Thanks — I already found them I believe and I'm tempted to buy a set even though I don't need them, strategic reserve or whatever you want to call it.
 
Thanks — I already found them I believe and I'm tempted to buy a set even though I don't need them, strategic reserve or whatever you want to call it.
no doubt!, mine were packaged really well and the finish looks brand new. only think i had to do to make them work was slightly enlarge one of the holes on the rear foot peg mounts and they bolted right up, excellent fit too.
 
i have to put rebuild kits in the carbs
If you aren't already aware, do not replace any hard parts (brass, etc) in your carbs with parts from carb kits, they are notorious for having incorrectly-sized jets, float needles and more. Clean and re-use your parts unless it's absolutely necessary that you replace them, and if you do need replacements get them from a reputable seller like Sirius Consolidated or JetsRUs
 
If you aren't already aware, do not replace any hard parts (brass, etc) in your carbs with parts from carb kits, they are notorious for having incorrectly-sized jets, float needles and more. Clean and re-use your parts unless it's absolutely necessary that you replace them, and if you do need replacements get them from a reputable seller like Sirius Consolidated or JetsRUs
they were full of old gas from presumably the 70s that had basically turned into almost resin. it took almost a full day to clean them. it runs ok now but i still have a very inconsistent idle and sort of a run on idle after giving it throttle (RPM staying up for a few seconds after coming all the way off the throttle.) i have a sync tool kit coming from those guys in Houston that should be in tomorrow. hopefully that will help. im going to try and get them tuned like they are before attempting to put the rebuild kits in. i also need to order a jet kit, i have pod filters on it (also from those guys in Houston) and these new mufflers, im sure it needs a bigger jet.
 
The floating down to idle could easily be loose springs on the advancer allowing the timing to stay advanced longer than it should, which always contributes to the problem of returning to idle properly. Be advised that pod filters on CV carbs are often next to impossible to get tuned properly, and many get tired of chasing it and give up. The bike was designed to use the complete intake tract that came with it from the factory for best all around performance. These engines are more sensitive to small changes than, say, a car V-8 where changing an air filter or plenum chamber has far less effect running through a single carb or throttle body feeding multiple cylinders. And, you should consider shopping around for all your parts, those guys in Houston might be convenient but they mark up their parts more than any other supplier we know of. Here's a great example, the solid state rectifier/regulator combo unit we recommend to replace the separate rectifiers and regulators on these bikes are likely from the same manufacturer that those guys in Houston buys them from - but you pay $65 for it from those guys in Houston, and you pay $37.50 for it from Sparck Moto.


https://www.those guys in Houston.com/honda-cb-cl-rectifier-regulator
 
The floating down to idle could easily be loose springs on the advancer allowing the timing to stay advanced longer than it should, which always contributes to the problem of returning to idle properly. Be advised that pod filters on CV carbs are often next to impossible to get tuned properly, and many get tired of chasing it and give up. The bike was designed to use the complete intake tract that came with it from the factory for best all around performance. These engines are more sensitive to small changes than, say, a car V-8 where changing an air filter or plenum chamber has far less effect running through a single carb or throttle body feeding multiple cylinders. And, you should consider shopping around for all your parts, those guys in Houston might be convenient but they mark up their parts more than any other supplier we know of. Here's a great example, the solid state rectifier/regulator combo unit we recommend to replace the separate rectifiers and regulators on these bikes are likely from the same manufacturer that those guys in Houston buys them from - but you pay $65 for it from those guys in Houston, and you pay $37.50 for it from Sparck Moto.


https://www.those guys in Houston.com/honda-cb-cl-rectifier-regulator
Great info, thank you. i have been noticing the price differences between them and other sites. i have only got couple things from them so far. Is there a list of recommended sites that many people on here use anywhere? also good to know about the factory filters, i only bought the pods because they were way cheaper than those guys in Houston's factory style replacements they had. the ones i took off were not dirty but the elements were falling apart. once again thanks for all of this info, this is a new world for me lol.
 
t runs ok now but i still have a very inconsistent idle and sort of a run on idle after giving it throttle (RPM staying up for a few seconds after coming all the way off the throttle.) i have a sync tool kit coming from those guys in Houston that should be in tomorrow. hopefully that will help.

I guess you're going to do a vacuum synch? Did you bench synch the carbs while you had them off? That adjuster was something I never liked about the original carbs, but the tool helps a lot!
 
I guess you're going to do a vacuum synch? Did you bench synch the carbs while you had them off? That adjuster was something I never liked about the original carbs, but the tool helps a lot!
you are correct, and yes i bench synced them based on a video i found. (my first time doing this)
 
Is there a list of recommended sites that many people on here use anywhere?
Did you go through the entire Welcome Package of links I posted in my reply to your introduction? There's one in it called "Tips for identifying and locating parts".
because they were way cheaper than those guys in Houston's factory style replacements they had
Again, one of our sponsors here is Scrambler Cycle (also in that list) and they have the same air filters for less than half the price.

 
Did you go through the entire Welcome Package of links I posted in my reply to your introduction? There's one in it called "Tips for identifying and locating parts".

Again, one of our sponsors here is Scrambler Cycle (also in that list) and they have the same air filters for less than half the price.

thanks! i notice that this is for a 350, will these also fit the 360?
 
thanks! i notice that this is for a 350, will these also fit the 360?
My mistake, I was thinking 350 when I typed that. I'm guessing not because the part numbers are different, but others here with more knowledge of that situation will have to verify.
 
My mistake, I was thinking 350 when I typed that. I'm guessing not because the part numbers are different, but others here with more knowledge of that situation will have to verify.
cool thanks, i went on the 360 tab on that site and he doesn't have any listed there. however the price differences are great! thanks. just went through that tab on helpful links thread. great info!
 
IMG_2264.jpegUpdate: finally cleaned it. got the chain on today, carbs tuned slightly better and got it running good. Got the front brake bled and working. Rode it about 5 miles with no issues. Only issue I am currently having is I have no power to the headlight and no tail light, only a very dim brake light. Bulb is new. I took the headlight out and bench tested it, both the high and low beam works. Fuses test good too. Slight corrosion cleaned at fuse box and still no dice. Any suggestions?
 
Those pipes look pretty good on there!
You're going to have to check all the other connections for corrosion.
What happened to the side covers? Looks like someone blew up the battery.
 
Only issue I am currently having is I have no power to the headlight and no tail light, only a very dim brake light. Bulb is new. I took the headlight out and bench tested it, both the high and low beam works. Fuses test good too. Slight corrosion cleaned at fuse box and still no dice. Any suggestions?

Two Possibilities:
  • The headlight and taillight are on a switch on the right hand control — you have that in the ON position?
  • The 360 electrical system has three fuses, main, headlight, and tail light. If the switch checks out, have a look at these fuses. I believe the stop light is on the main fuse.
You have the factory service manual already?
 
Those pipes look pretty good on there!
You're going to have to check all the other connections for corrosion.
What happened to the side covers? Looks like someone blew up the battery.
I never thought of that, does look like a possibility. Those splatters are where it stripped the paint down to the plastic. And thank you! They sounds great too.
 
Two Possibilities:
  • The headlight and taillight are on a switch on the right hand control — you have that in the ON position?
  • The 360 electrical system has three fuses, main, headlight, and tail light. If the switch checks out, have a look at these fuses. I believe the stop light is on the main fuse.
You have the factory service manual already?
I had the switch in the on position, yes sir. The switches did check out. I have the manual that was under the seat but it’s a little fragile. I need to find one online and print it out possibly. Thank you!
 
I had the switch in the on position, yes sir. The switches did check out. I have the manual that was under the seat but it’s a little fragile. I need to find one online and print it out possibly. Thank you!
What about the fuses? (Also located under the seat.) If the fuses checked out, I would start tracing the wires checking for 12V to locate the issue.

You may need to contact an administrator, but the forum has a collection of factory service manuals (more info than the owner's manual) and hopefully can help you get the manual for the CB250/360.
 
What about the fuses? (Also located under the seat.) If the fuses checked out, I would start tracing the wires checking for 12V to locate the issue.

You may need to contact an administrator, but the forum has a collection of factory service manuals (more info than the owner's manual) and hopefully can help you get the manual for the CB250/360.
Tracing wires is my next step. Thanks for the info and the help.
 
IMG_2305.jpegLittle update, got the headlight working along with the tail/brake light. Issue was a corroded ground near the center of the bike. However the starter did ground out, luckily I still have my kick start for now lol. I rode it around 25 miles today. It seems that the charging system is weak or something is going bad, if I run the headlight the entire time it eventually drops voltage low enough to start misfiring. I can turn the headlight off and comes back around. So some more progress made along with some more parts to address!
 
It seems that the charging system is weak or something is going bad, if I run the headlight the entire time it eventually drops voltage low enough to start misfiring. I can turn the headlight off and comes back around.

With the headlight switch on, the charging system is supposed to produce more power, so something is definitely amiss.

It's not super hard to measure the AC output from the stator, check resistances of the coils, or check for connectivity to ground.

A modern rec/reg is never a bad Idea, either, such as the 12V single phase unit from Sparck Moto.
 
With the headlight switch on, the charging system is supposed to produce more power, so something is definitely amiss.

It's not super hard to measure the AC output from the stator, check resistances of the coils, or check for connectivity to ground.

A modern rec/reg is never a bad Idea, either, such as the 12V single phase unit from Sparck Moto.
How does one check 'live' output in the bike? I've yet to learn this skill.
 
How does one check 'live' output in the bike? I've yet to learn this skill.
Tom's summary is more than adequate, but Steve also wrote up a lesson that provides reasonable expected output for certain models. Sometimes the coloring on the wires is so faded that they must be identified by the resistance measurements.
 
Sounds so simple. Just check each pair with meter set for AC voltage?
I was reluctant to run the bike with the stator disconnected.
 
Earlier I mentioned from the side cover damage it looked like someone blew up or boiled over the battery.
I wonder if someone tried to jump start it from a car or tried to quick charge the battery and damaged the electrical system.
 
Earlier I mentioned from the side cover damage it looked like someone blew up or boiled over the battery.
I wonder if someone tried to jump start it from a car or tried to quick charge the battery and damaged the electrical system.
Could have smoked the rectifier if the car was running at the time.
 
Could have smoked the rectifier if the car was running at the time.
I am probably going to end up replacing the charging system and related components to avoid issues down the road. Would sparck be about the best place to look for these parts? Thanks

Would this be the appropriate reg/rect?
 
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I am probably going to end up replacing the charging system and related components to avoid issues down the road. Would sparck be about the best place to look for these parts? Thanks

Would this be the appropriate reg/rect?
Yep, that's the one. Best value out there for a quality rec/reg combo unit. Start with that and go from there, the alternator stators and rotors are a less common fail.
 
Check under fuel tank and find yellow wires going to right side handlebar switch.
Disconnect and fit a jumper to bypass the switch so you have full output at all times.
A modern regulator rectifier from Matt should sort out charging and save cost of new stator which I haven't found necessary on any of my 360's.
You can't just jet the 250/360 for cheap pods (actually they restrict airflow over 6~7,000 rpm).
I always recommend K&N filters but 3 jet Kei-Hin carbs need re-working to prevent crazy rich mixture somewhere around 4,500 ~ 6,000 rpm (also depends on exhaust system/length)
Probably a good idea to search out the oil transfer piece modification, 250/360 needs it more than 350 but it's a good mod on any Honda twin.
 
Check under fuel tank and find yellow wires going to right side handlebar switch.
Disconnect and fit a jumper to bypass the switch so you have full output at all times.
A modern regulator rectifier from Matt should sort out charging and save cost of new stator which I haven't found necessary on any of my 360's.
You can't just jet the 250/360 for cheap pods (actually they restrict airflow over 6~7,000 rpm).
I always recommend K&N filters but 3 jet Kei-Hin carbs need re-working to prevent crazy rich mixture somewhere around 4,500 ~ 6,000 rpm (also depends on exhaust system/length)
Probably a good idea to search out the oil transfer piece modification, 250/360 needs it more than 350 but it's a good mod on any Honda twin.
I plan on putting an oem style filter set back on it. Just haven’t ordered them yet. Thanks for the info!
 
Update, I have the front end pulled apart to powder coat some pieces, have the center and kick stand off to be powder coated as well. I’ll be doing the brake lines during this time as well as putting the new triple tree on. Took the carbs back off to finally do the rebuild kits but found I need diaphragms too, looking at the ones on CM. As expensive as they are… lol 35$ for one. Really enjoying working on this project.
IMG_2359.jpeg
 
There are better choices for diaphragms, someone here will let you know where.

Found this in a VHT site search

 
I remember getting diaphragms from eBay seller about $35 a pair earlier this year.
Forget if it was for 350 or 360 though.
They turned out to be very good quality so I think the size also fits something current?
They looked identical to the ones from 4into1, you don't really need the extra o-ring though as diaphragm fitted into throttle slide recess.
I have a piece of aluminium handlebar and a fixture to hold slide so I can press the nylon washers off then re-roll the top of slide so it's close to OEM
I just ordered some for my Suzuki even though I don't actually need them at present because it was such a good deal.
 
Was out riding yesterday and noticed my lights getting dim. It was not charging. Came back and took the stator cover off and all the oil from the crank case ran out of it. I’m assuming there’s a seal in there. I didn’t disassemble any further as I didn’t have much time. I figured I’d jump on here and ask if anyone knew where to find that seal? Thanks.
 
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