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General Category => Tech Corner => Topic started by: hawkwind on April 12, 2022, 10:32:56 AM



Title: Leaking carbs
Post by: hawkwind on April 12, 2022, 10:32:56 AM
Stood for 4 years.
New float valves and seats, yep.
New pilot screw O-rings, yep (had to use dentist picks to remove old ones).
New float seals, yep.
Float heights set (8mm) yep.
Fuel still dripping heavily from all four carbs.
Any suggestions people?


Title: Re: Leaking carbs
Post by: Spurlock on April 18, 2022, 09:20:21 AM
Clean everything up and pinpoint where the leaks are from. You don't mention replacing the fuel fittings and O-rings parts #2 and #3 in this diagram:
https://www.partzilla.com/catalog/honda/motorcycle/1989/cb400f-a-cb-1/carburetor-assembly
 (https://www.partzilla.com/catalog/honda/motorcycle/1989/cb400f-a-cb-1/carburetor-assembly)

Those are most likely the problem. By "float seals" do you mean the float bowl gaskets and float bowl drain screw O-rings? Those need to be new. Also if the float bowls are switched between carbs they will not seat against the carb bodies, due to a small raised boss near the mixture screw on each carb body.

-Bill

Stood for 4 years.
New float valves and seats, yep.
New pilot screw O-rings, yep (had to use dentist picks to remove old ones).
New float seals, yep.
Float heights set (8mm) yep.
Fuel still dripping heavily from all four carbs.
Any suggestions people?


Title: Re: Leaking carbs
Post by: hawkwind on April 20, 2022, 06:27:15 AM
Cheers Bill,
I've got a full set of rings and gaskets coming from Thailand and I'll replace the fuel line O-rings as well.
I'll check bowl to carb matching very closely.


Title: Re: Leaking carbs
Post by: a_morti on April 21, 2022, 10:34:55 AM
Cheers Bill,
I've got a full set of rings and gaskets coming from Thailand and I'll replace the fuel line O-rings as well.
I'll check bowl to carb matching very closely.
I assume you've not been able to identify exactly where it's leaking from?
Those seals from litetek will solve it, most likely. If not, reassess from there.