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Discussion Starter #1
Hello All,

I suspect one/both of these bleeds are clogged on my CB360 carbs. Idle mixture adjustments provide very little if no changes to the idle. I also get stalling at times when coasting to a stop when the bike is hot.
The troubleshooting guide lists this as a likely, common culprit for both situations. All other fix-it options have been attempted. The bike has been tuned and runs like a top otherwise. What is the best way to clear the bleeds, and where are they exactly? A diagram would help if anyone has that handy.
Thanks in advance for your advice.

Will
 

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You have to strip carbs to get at them. Use a chopstick to push the primary main jet discharge tube out of carb, it's usually pretty tight. If bike seems to be running OK it's doubtful they are completely blocked. I have a stack of pictures but your probably aware of Photobucket's ploy to make money so I can't post tem here. I also have them on desktop but not laptop
 

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Discussion Starter #3
Thanks for the info, PJ. My post count should tell you I'm not familiar with photobucket. Pictures would help when I take them off the bike for the third time (other times, other problems). Could you send a few in some other fashion? So it's not the tiny holes at the bottom of the carb throat. I have to take them off anyway to do some jet sizing. Thanks a million.

Will
 

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The bypass holes only really operate during transition as throttle plate opens. I doubt they are doing anything by 2500rpm?
The cross holes in pilot jet are 0.80mm dia and the others in emulsion tubes 0.60mm dia. Photobucket gave about 48hrs notice that they were oin to charge $399.00 a year for hosting pics. I only have 0.5Gb on there so they can piss up a rope. They also made it impossible to download an album, you have to download individual pictures. Some people with 4~5Gb stored have been forced to pay but I think they screwed themselves as majority will refuse to be 'blackmailed'
I don't know if direct link to album will work but guess it's worth a try?
http://s91.photobucket.com/user/1crazypj/library/Carburettors?sort=3&page=1
 

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Discussion Starter #5
Thanks for the photo link. I'm not sure, though, how those relate to accessing the air bleeds to check/clean them. Are there any diagrams available that would help me zero in on these? I'm still a bit lost.

Will
 

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The air bleeds are underneath diaphragm, several diagrams available,
There are 3, low speed/pilot on it's own one side, primary main jet, secondary main jet, sizes, 80, 150, 50
Trek97 on DTT is best bet as he's got everything I sent, told and explained to him in one place. (may be on here as well?)
You have checked the 'sticky' at top of carb page?
 

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Discussion Starter #7
HI PJ. I've been out of town for two days. Yes, I'm familiar with those bleed holes. So those are the culprits. As I recall the last time I had the carbs out I removed the diaphragms and tried to poke wires through the holes just to ensure everything was clear. Is there anything particular that has to be done when attempting to make sure they are free? In your first response to me you mentioned to remove the primary main jet discharge tube. How is that related to the air bleeds? Maybe I'm confused again on what the discharge tube actually is. For background info my jets are the stock 35/68/100 and are all clear of obstructions. Yes I reviewed the sticky.
 

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The air bleeds are to restrict amount of air going to various emulsion tubes.The emulsion tubes have cross drilled holes and are the probable cause of bad running. If you took a look at pics you'll see a lot of messed up discharge tube/emulsion tubes before and after. You need to get a pin chuck and micro drill set of eBay then use correct size drills to clean out holes (plus modify aftermarket pilot jets as cross holes are too small (0.60mm instead of 0.80mm)
Your better off squirting carb cleaner through them, pushing wires in there will damage them
 

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Discussion Starter #9
Oops. I'll try the carb cleaner next and really give them a good dousing. It will be a while before I respond since my daughter has the bike for at least a week. Last fling before the cold- it's her bike. I'm just the one who fixes stuff, and fixing this thing keeps me busy. Carburetion and electrics are not my specialty as you may already know.
I saw the emulsion tube pictures. They don't look familiar from what I recall when last I had the carbs apart. Are they what the main jet attaches to (the 100s in my case)? If so, that's the main jet discharge tube you wanted me to push out with a chopstick in your first response.?! You don't have to tell me more than three times before I get it.:confused:
The pilot jet (35) holes are all clear, but you're saying the cross holes are too small to function correctly? As far as I know that jet is original. If not, wouldn't it help to replace it with the next larger jet (38) or would the cross holes be too small as well in that one?
 

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Discussion Starter #11
Thanks. That explains a few things that PJ mentioned earlier, locations of items, etc. I initially thought the 50/150/80 was in reference to the lower jets. The light is starting to come on. Jets, jets, jets.
BTW the oil leaks are history. The compression did go up about 15psi when I added the oil and rechecked. Lucky me. I see you've had some complications with your rebuild. I hope things are getting straightened out on that front.
 

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I have this stickied:

CB360 carbs
Trek has done a new 360 carb thread but I can't remember title.
The primary main jet discharge tube is under the 68 primary main jet and is the one that needs carefully pressing out
It most likely the one with problems.
 

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Discussion Starter #13
When you remember the thread please lay it on me. The one krukster listed was good for me. In my case more is better. I thought I knew about engines, but it's turning out I don't know much about carbs for sure.
I can't wait to tear those puppies apart again and find something wrong. That would be a relief. She should have it back to Pop's shop and me working on it before thanksgiving. Once that is squared up the top end work will begin. Hopefully only some rings and a honing. I'm not there yet. Time will tell.
I will write again when I know more. In the meantime Happy Veteran's Day!
 

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Discussion Starter #14 (Edited)
I finally got to the carbs and reexamined every piece. Cleaned and spit shined. One 50 air jet was slightly contaminated, but not plugged. I doubt that would have been the culprit, especially since it was only in one carb and the problem is present in both. So the mystery continues. In the meantime I will be starting the top end rebuild and won't be checking the carbs until the engine is back together. With any luck I can get it done around christmas.

In the meantime, any other ideas out there to help explain/solve the idle mixture setting and stalling would be appreciated. It will give me some food for thought, or to keep me up at night pondering those alternative ideas.

Happy thanksgiving.
 

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Discussion Starter #15
Update time. The top end has been dismantled. Waiting on some items before sending off the head and cylinder to be checked and reworked if necessary. There seems to be minimal wear on the cylinders and a leak check on the valves showed only the slightest weeping on one exhaust valve. I don't see any obvious reason for the low compression readings I was getting beforehand. Checking the compression by adding oil in the cylinder gave a 15psi boost. So I will be very interested in the machining results.
 

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Discussion Starter #17
When I flipped over to the thread I had to search a bit. I think the pertinent info starts around p 112. I'll give it a study. Just sent the head and cylinder to TOOLS1 today. So I'll have time to tear the carbs up again if needed while I wait.
 

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Discussion Starter #18 (Edited)
Two week update. The head has both bad exh valve guides, otherwise all is well. Parts wont be back for another week or so. Meanwhile I tore up the carbs again to double check a thing or two based on the Trek thread. I reset the float level per pj's advice and revisited some of the brass orifices and made water flow through my tiny breather holes like the ones in the Trek thread picture, p112 of 115. And they do.

Sure do hope the idle settings tune as they should when I finally get this mess together again. Otherwise, with lots of the engine getting a spit shine in the meantime, it'll be 'all show and no go'.:lol:
 

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As long as you run stock air-boxes (even with re-built filters) you shouldn't have any running problems. If you do, check charging and points gap / timing /advancer operation. Trek has everything covered but it may need a little searching. BTW, if you sign it to DTT 100 pages drops to about 20 longer ones. I only found out by telling someone to look at page 18 or 19 on my build / blog / BS. When I checked, it was about page 112 :eek:
Also, if you try and run cheap pods you will ave nothing but problems.
Even K&N or Uni's only work to 4,500~5,500 rpm brfore things go haywire (until I modify them ;)
 

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Discussion Starter #20
PJ,

Yes, mine are stock, and the mufflers are not. But they are new and at least run past the axle (22"). Much better sound, and tone, than the shortys it was bought with. I was exaggerating for effect overall to garner maximum sympathy. The idle thing ticks me off though (the original thread focus). Yes, I get you about the page. It comes up that way, though, when I reference it. Good point.

Merry christmas. Chronologically that will come now before I can report on carb running condition. "I want a newly rebuilt CB for christmas. Only a rebuilt en-gine will do. Don't want a doll, a dinkey tinker toy, I want a CB360 to play with and enjoy."

Is dat you, Santi Claus?
 
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