SOHC.co.uk Forums > CB350/400
Carb work
mattsz:
I'm beginning to think about my carbs.
The PO says everything was running fine when the bike was stored, but I know the bowls weren't drained and the fuel dried out. I opened one carb up, it doesn't look all that bad, but some attention is needed. Here's a post with a couple photos attached, nothing too surprising there:
http://www.sohc.co.uk/index.php/topic,17461.msg150591.html#msg150591
And here's a couple more (click to zoom). The float valve seat's o-ring is typical of the rest of them in this carb, dried out and cracking apart. Obviously, all new o-rings needed:
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The float valve - showing signs of age, but I can't feel any texture or ridge at the seat with a fingernail, and the spring action is smooth. Ok to try out, or should I just go right with new?
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Float bowl screws: 15 all the same, one different... ::)
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The jets and brass bits all seems pretty clean, so I'm hoping I can reuse them. Of course, things could be different in any of the other carbs!
mattsz:
Regarding the choke lever action: there's a slight amount of play in the linkages between each carb. With full choke, all the plates are closed, of course. As I rotate the lever to reduce the choke, the #1 plate rotates right away - but there's a slight lag before the #2 plate begins to move. Same with #3, and then #4, all "cascading" as I rotate the choke lever. As a result, when the choke lever reaches the limit of its travel, the #1 plate is noticeably "more open" than the #4 plate, with 2 and 3 in the middle somewhere. You can see that condition in this photo:
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Is this ok, or should I be looking at trying to adjust the linkages to equalize them?
My initial plan is to try to clean the carbs without separating them, and reassembling with new o-rings (definitely) and jet, float and seat parts (maybe) to see how it goes...
taysidedragon:
Yeah, use the adjuster screws to equalise all 4 butterflies so they move together inline. Don't forget to tighten the locknuts afterwards. 😉
Nurse Julie:
Be careful with the threads on the float bowl screws, they strip for fun due to being so fine and old alloy. I got Graham to helicoil all 16 of mine when I refurbed my carbs.
mattsz:
--- Quote from: Nurse Julie on January 18, 2019, 03:21:58 PM ---Be careful with the threads on the float bowl screws, they strip for fun due to being so fine and old alloy. I got Graham to helicoil all 16 of mine when I refurbed my carbs.
--- End quote ---
Thanks for the warning! But... assuming you're talking about removing them - how does one be careful with them? Apply penetrating oil and hope it soaks in before trying to remove the screws?
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