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Tapping noise, and other things along the way

teebo said:
Replace? Hahahaha

Those appear to be set and the aluminum edge rolled over.

I have a rather pessimistic outlook of finding used caps in perfect shape. 4 carbs. 4 leak. I’d be better off most likely just buying some NOS carbs. They’re out there. For a price.

I’m trying a thin epoxy seal around the circumference.
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I’m not suggesting replacement. The Goldwing caps are NLA and most just fix and seal the existing ones like your doing.
What tweaked my curiosity was when you noted the no change in the lean condition with the main jet from a stock one to a much larger size. That’s impossible, unless something is off with the slide function. Since if it was operating correctly then you would be overly rich which your not.
 
Flyin900 said:
I’m not suggesting replacement. The Goldwing caps are NLA and most just fix and seal the existing ones like your doing.
What tweaked my curiosity was when you noted the no change in the lean condition with the main jet from a stock one to a much larger size. That’s impossible, unless something is off with the slide function. Since if it was operating correctly then you would be overly rich which your not.
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I don’t believe I’m debating the slide operation is a possible/likely culprit.

I’m just saying that I’m attempting a sealant before trying to find replacement caps. Because it will likely involve a lot of luck or a lot of purchases.
 
WintrSol said:
The needle jet/jet needle determine fuel flow during mid-range operation. condition (c) in the quad diagram, above, and depends on the amount the piston is lifted by the vacuum formed by the air flowing under the piston, complements of the Bernoulli effect (not from the engine vacuum, although that determines the flow rate), This makes the velocity of the air through the venturi to remain relatively constant (CV).

If there is too little restriction in the air filter, the pressure difference between the air above the fuel in the bowl (which vents to atmosphere through the overflow) and that in the rest of the carb is lowered, so less fuel flows through the jets. As the amount of air pumped by the engine rises, this difference normally increases, but less so with less restrictive filters, which is why CV carbs are lean with lower filter restriction. To compensate, the needle jet/jet needle jet would have to have a larger gap during mid-range operation; the main jet has some effect, but not as much as the needle jet, until WOT is approached - condition (d).

The air jets cause bubbling in the chambers above the jets, which allows for better atomization of the fuel and, because of that, better fuel spray into the air stream. Without them, the fuel comes out in bigger drops, which don't burn well.

The vent between the piston vacuum chamber and the tube that guides the piston just prevents pressure building above that part of the piston.

The pilot circuit uses two jets to better stabilize the fuel flow rate.
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As far as air flow, I keep coming back to Jensen stating that a less restrictive foam (unifilter bf-6) works and shows little difference on a dyno.

My thoughts are around is the 65 ppi too dense, the BF-6 closer to stock, and finally, perhaps switching to a paper filter. All for trying to get closer to stock.
 
I regards to your question above. I wonder that myself, as I have never seen this set up with stacked jets that receive fuel from the float bowl and fuel through a cross passage off the main jet. Pretty bizarre design, yet clearly there is a reason and Keihin did this for that reason. No modern 70's or 80's carb I have worked on ever used that set up!
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Don't forget that these carbs were the first CV carburetors being used on a "over the counter bike" ever.
 
Did you do the choke test already ? Warm up the bike, at 5000-6000 rpm plug chop, then 1/4 choke, at 5000-6000 rpm plug shop, then 1/2 choke, at 5000-6000 rpm plug shop. The mixture should be richer at 1/4 choke, and at 1/2 plugs should black.
 
jensen said:
Did you do the choke test already ? Warm up the bike, at 5000-6000 rpm plug chop, then 1/4 choke, at 5000-6000 rpm plug shop, then 1/2 choke, at 5000-6000 rpm plug shop. The mixture should be richer at 1/4 choke, and at 1/2 plugs should black.
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Thanks Jensen. Next test I’ll do exactly this. Right now the carbs are off. Getting a good seal around the plastic on the caps. I check the various passages again. It probably won’t be today.
 
A final though from the cheap seats!

Maybe those leaky plastic top caps are the culprit and causing the issue with your lean/slide operation. If the stock main jet is #135 and your presently at #150, you may find it runs like crap, or is now too rich over the broad range of operation.
You still may have some of the smaller main jets to switch into the carbs if that is the case. Hopefully your closer to a solution in resolving this problem.

That's all I have! That's why I have some bikes that are rec room queens. ;)
 
Flyin900 said:
A final though from the cheap seats!

Maybe those leaky plastic top caps are the culprit and causing the issue with your lean/slide operation. If the stock main jet is #135 and your presently at #150, you may find it runs like crap, or is now too rich over the broad range of operation.
You still may have some of the smaller main jets to switch into the carbs if that is the case. Hopefully your closer to a solution in resolving this problem.

That's all I have! That's why I have some bikes that are rec room queens. ;)
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Jensen suggested I put back in one over. So I’m back to 140. And runs better with 38’s.

But if I can get enough air, I can bump to 155’s and 45’s. ;-)
 
Jensen suggested I put back in one over. So I’m back to 140. And runs better with 38’s.
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Yes, for 3/4 reasons, they are:

- Anti fuel economics
- Breaking in
- Safety at WOT
- Summer use (high temperatures)

The first reason needs a short explanation, Honda, in the sixties, was advertising with good fuel economics. In general, the early Honda's run lean on the main jet, being a little too small. I have seen this (with the gas analyzer) with the CB72's, but also with the 450's and lately, the CB400F.

Unfortunately, there isn't a step in between 135 and 140. After breaking is, I would prefer a 138. In the dyno chart below, you can see that the mixture from around 6500 rpm and on get's a little rich, around 13, and above 8000 rpm to 12.5 (remember, I'm at sea or even below sea level). Maybe at your place, the 140 is too rich after the breaking-in.

1710697375006.jpeg
 
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Between 4000 and 6000 rpm, the fuel economics is good, with a nice 13.5 A/F ratio. Opening the throttle too quick with these early CV carburetors will result in a lean condition.

Your bike will behave more or less the same after you solved the problem, it's best to open the throttle rather slow than quick.
 
5K is not a good place to check plugs (or anything)
The slide doesn't lift until airflow increases, (somewhere around 5K) it could be 'fluttering' and giving weird readings.
There are a few rpm ranges where 'testing' shouldn't be done.
1,500~2,000 rpm, advancer is moving but not 'locked' in position.
4,000~6,000, slides are moving but airflow isn't stable enough to keep them 'static'.
When road testing, stay above or below the rpm bands for better results
teebo said:
Not a lot of choice here. I’ve never seen usable K0 filters for sale. Hard to find even crappy ones.

Perhaps using similar paper from a different filter?

I seem to recall jensen saying something about that.
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It was quite common to use a 1970's Chevy large round 3" high paper filter to 'repair' various motorcycle filters as OEM were 'quite expensive' (Kawasaki and Yamaha in particular)
For the car question, all the pedals and gear-change 'gate' have been standardised since about mid 1920's.
I think it was Cadillac who came up with the 'H' pattern and clutch pedal position around 1915?
Ford had some weird set up in model T, Henry wanted complete control and monopoly over everything.
I guess I learned way too much 'pub quiz' information? :ROFLMAO:
 
5K is not a good place to check plugs (or anything)
The slide doesn't lift until airflow increases, (somewhere around 5K) it could be 'fluttering' and giving weird readings.
There are a few rpm ranges where 'testing' shouldn't be done.
1,500~2,000 rpm, advancer is moving but not 'locked' in position.
4,000~6,000, slides are moving but airflow isn't stable enough to keep them 'static'.
When road testing, stay above or below the rpm bands for better results
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Agreed, but I won't advise going above 6000 rpm as long as the bike runs very lean (according to Teebo), and looking at the dynochart, the stability around 5000 to 6000 rpm is good enough to plug chop to get an impression.
 
Choke test results. This is after sealing the caps around the plastic.

Choke open, not a consequential difference. Perhaps a little.

IMG_1628.jpegIMG_1629.jpeg

Quarter open:
IMG_1630.jpegIMG_1631.jpeg

Half open:

IMG_1632.jpegIMG_1633.jpeg
 
If they were clean plugs then the choke open looks not bad at all depending how far you rode the bike. A ride of 25-50 miles varying the RPM up to 6K and below and then look at your plugs. I would keep it somewhat local unless you have AAA to give you a flatbed lift back home if the engine starts to act up. The 50% choke looks somewhat rich, again depending on the ride time/distance. I suspect the other position was 1/4 closed, or is your statement of 1/4 open meaning it was 3/4 closed?
If so it is leaner than the 1/2 open setting and the reason for my question about that one statement.

Maybe show a picture of the clean plugs before hand to get a better reference. I am looking at not only the white porcelain but the metal angled tang and the rim around the outer plug edge. Without a before picture of the plugs it is hard to know what changes your encountering.

You maybe dealing with a condition of too much air into the carb from the foam, yet that's just speculation. The sealing of the plastic caps looks like it did richen up the burn on the plugs slightly. The choke made the most difference though.

Honestly, I am not sure if you have a problem still at this point. It isn't totally clean and white like a new plug with no deposits. All depends on how they started out on this test as noted above.
 
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They were not new plugs. Between the first test and this there would have also been several miles.

Left is also a bit richer than right.

I’d bet money I could drive 600 miles and they’d be the same color. I know because this is exactly the same behavior as first rebuild. They will never be tan. At best a very light grey.

I don’t know. I can try paper in the filters. I can try the same foam that jensen has (but that is less restrictive).

Not really down with a third set of carbs unless it’s something entirely different. Like mikunis. Or something definitive to explain it.

However, I did figure out another problem. Sometimes after a ride my starter doesn’t work. It’s the darn solenoid. Tap it with something and it works again. Now that is something that makes sense. Ha.
 
I would just ride it frankly for a break in period and call it OK for now. My two CB1000C's that I sold last year also showed a non tan colour plug set of four which I put down to the ethanol gas I use these days. I don't use the non ethanol gas! I don't believe there is any difference in anything including the O rings etc. Mike Nixon (aka old fart) on this forum did a piece recently on ethanol gas that I subscribe to personally too.

Ride it and you can always close the choke slightly if you suspect it is running too hot, or starts making a noise again. If you don't have AAA it is worth it when you are messing with bikes like this, or a buddy on speed dial with a trailer. :)

I would clean up the plugs like new to see what changes are happening when you ride it. I have a spark plug cleaner and Harbour Freight must sell one too. It was like $25 bucks and uses compressed air from your compressor and fine grit to sandblast the plugs clean. Important to really use a liquid cleaner and comperssed air to remove all the grit from the interior porcelain area and threads though before reinstalling them.
 
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I don't think plugs will ever be tan, as that color came from the lead. Shades of gray are mostly what we can expect, with varying thickness of carbon build up.
 
On my Bomber the starter solenoid can be taken apart and cleaned. Later ones are sealed. Mine was really dirty inside and only made contact occasionally, but after a good cleaning things work much better.
 
Hey Teebo, It's been a while. Not sure where you're headed with your solenoid but mine was completely seized. Took it apart and had all the pieces vapour blasted, reassembled and works great. Post #112 on my old thread has a few pics.
 
Thanks all for the help on this. Really do appreciate it.

I’m not worried about the solenoid at all. It was disassembled early in the restore and this behavior has gotten steadily worse. Rebuild or replace. Simple.

This bike is tedious enough to start with the starter working. No way I’m coming out to kick it over until I get it started. I’ll need to fix solenoid first.

Just overall not a huge fan of how finicky this bike is. I fully realize it’s on me, but I really don’t trust it.
 
teebo said:
Thanks all for the help on this. Really do appreciate it.

I’m not worried about the solenoid at all. It was disassembled early in the restore and this behavior has gotten steadily worse. Rebuild or replace. Simple.

This bike is tedious enough to start with the starter working. No way I’m coming out to kick it over until I get it started. I’ll need to fix solenoid first.

Just overall not a huge fan of how finicky this bike is. I fully realize it’s on me, but I really don’t trust it.
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How disappointing for you that you have something that should be so awesome and you don't trust it. I hope that you get all of this resolved. (of course I'm still waiting to take mine out for it's maiden ride)
 
Teebo, it won't be like last time because you have a clean crank, etc., so no oiling issues. Just refurb some stock filters and ride that sucker.
Just grab another solenoid (since you already did this one once, they do wear out) from 4into 1 that has a bracket that will work.
 
Troy said:
How disappointing for you that you have something that should be so awesome and you don't trust it. I hope that you get all of this resolved. (of course I'm still waiting to take mine out for it's maiden ride)
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I’ll work it out. Just throwing a tantrum. Whah.

First I need to call it names for a bit.
 
Not fixed but interesting anyway.

I wanted to make sure I wasn’t crazy and had my memory mixed up about why I switched to the 14H’s from the original 14C.

I had a number of issues with the 14C that I resolved. But it was showing lean too. I recall sending a pic and ancientdad commented that it wasn’t getting much gas. But one of the slides was sticky. The kind of sticky that would let loose with a little wiggle. Not all the time. I could usually tell when it did that. So I put the 14H’s on.

I just put the 14C back on after fixing Mr Sticky. Still lean. But. It’s like a different bike. As soon as I did a rough idle mixture setting I could tell. Smoother idle. Smoother off the line. That shift into 2nd just felt better. It does have the 135 mains.

I mean I first thought it was a little rough with the 14H’s. But the 450’s vibrate so I thought that was it.

That’s my story. I’m thinking I’m not chasing the jet route again off the bat. Maybe chase the airflow path a bit more.

One of these days I’ll get all this carb stuff better.
 
100 mile oil change. I did run it through a coffee filter and cleaned oil filter.

No shiny specks at all. There was a trace, a residue really, of metallic powder in the oil plug and a bit more in the oil filter. No chinks. More like a powder. The little that was in the coffee filter was also just a trace.

Potential trick to speed this up. I ran a bit of oil through my Aeropress. For those who are unfamiliar, it’s a way to make coffee. There is a cylinder with a paper filter on the bottom. You add coffee and hot water, then push a plunger (just a piston with a rubber seal) into the cylinder. This forces the water through the coffee and filter.

This works for oil too. Though can’t apply too much pressure because the seal will let oil slip by with too much. Much faster than waiting on gravity.
 
WintrSol said:
I don't think plugs will ever be tan, as that color came from the lead. Shades of gray are mostly what we can expect, with varying thickness of carbon build up.
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Hmm, not so sure about this. I think he just hasn’t run them long enough yet. Might the tan come from slight oil burning? I mean these engines don’t even have valve stem seals and the piston rings aren’t the greatest at sealing either.

For what it’s worth, on my trucks (which do have valve stems seals and piston rings that work) the plugs always show perfect coffee/tan color
 
RockReef said:
Hmm, not so sure about this. I think he just hasn’t run them long enough yet. Might the tan come from slight oil burning? I mean these engines don’t even have valve stem seals and the piston rings aren’t the greatest at sealing either.

For what it’s worth, on my trucks (which do have valve stems seals and piston rings that work) the plugs always show perfect coffee/tan color
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My 350 is tan. I haven’t plugged chopped in some time though. No need. It just runs.

Just non-ethanol premium unleaded.
 
Finally. Still not 100% satisfied. But at least now when I do something, there is some reaction.

First: I started going the paper filter route last night. Got part way through and decided it’s nonsense. So much effort to remove the paper from a filter and work out the pleats and I then considered each time I redid it, they have to be close to the same.

So: I tried the reduce surface area route. I put a strip of gorilla brand tape on the top and bottom of each filter. So about a 3” reduction top and bottom. Lightly oiled foam. This is a temporary test.

Had a little color finally.

So I thought what happens with a 140. Nope. Chuggy at around 5k.

Also, and this was new to me. At idle, if I gave it a little goose, nothing extreme, then released one side or the other would backfire. Every single time.

So back to 135. The backfire stopped. Mostly. The left would every once in awhile, less as it heated up. Gave it a slight tweak leaner idle mixture on left.

I feel I’m right on the edge. Idles really well. Better as it reaches temp.
 
So you went to 140s after taping off the filters? If so, it seems like taping off the filters, at least for now while you're still running it in, might be the solution.
 
ancientdad said:
So you went to 140s after taping off the filters? If so, it seems like taping off the filters, at least for now while you're still running it in, might be the solution.
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I think so too. It’s actually like a 2” reduction top and bottom. I was just trying to find the upper limit.

Considering I went much higher with the other carbs I was pleased the 140’s failed.
 
teebo said:
I think so too. It’s actually like a 2” reduction top and bottom. I was just trying to find the upper limit.

Considering I went much higher with the other carbs I was pleased the 140’s failed.
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Dude, how many times have you taken the carbs off the bike now?!? I think I would have given up long ago. Mad respect!!
 
RockReef said:
Dude, how many times have you taken the carbs off the bike now?!? I think I would have given up long ago. Mad respect!!
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So. Many. Times. At least for this round I don’t need to.

I’m curious why the 14H’s behave differently. That answer will come in the future. Long after everything else is solved and bike is broken in. For now they are going in a box.
 
teebo said:
So. Many. Times. At least for this round I don’t need to.

I’m curious why the 14H’s behave differently. That answer will come in the future. Long after everything else is solved and bike is broken in. For now they are going in a box.
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I’m pissed because I have to do it to my Frankenbike (CB360 with 350 engine & carbs) again right now. The first time they leaked like a sieve from cracked overflow tubes. Now I got stranded on the side of the road last week. Drained carbs and found silvery residue in the bowls. WTF!
 
RockReef said:
I’m pissed because I have to do it to my Frankenbike (CB360 with 350 engine & carbs) again right now. The first time they leaked like a sieve from cracked overflow tubes. Now I got stranded on the side of the road last week. Drained carbs and found silvery residue in the bowls. WTF!
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Tank liner?
 
Curiosity question.

The FSM shows jet sizes as 38 and 135.

However, the shop manual shows this:

IMG_1646.jpeg
Thing is, my pilot screw setting is very close to this.

But, there was a discussion earlier about different pilot and slow jet sizes. So I guess that’s a thing? I don’t understand though.
 
I’ll be darned.

The 38 for both is for the 14H.

I put a 40 slow in my 14C and it idled bad.

But I read a post from crazypj on HT insisting that at idle, the main still affects things.

He’s right. Not that I doubted him. Put in a 130 and the isle is better.

I have a 125. But I have another question. My 125 and 130 are the newer style mains. Without the lip. Do they work the same as the earlier style?
 
jensen said:
How does the bike run in the mid-range ?
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I think it felt fine. If I have a complaint, it’s a little rough at idle and slow. When I first start it, it’s prone to stall until it warms up. Like for the first couple minutes. I worked most of that out yesterday. But I’m going to go back through tune and sync tonight.
 
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