Can you repair a carb diaphragm?

PlasmarZercson

XS400 New Member
Messages
2
Reaction score
0
Points
1
Location
Hamilton
Hey,

So I have an 82. Keeps stalling out on me. Went through the motions. Definitely got spark. Definitely got fuel going into the carbs. Pulled apart the carbs and found a tiny pin hole in one of the diaphragms. Don't know if that's my problem but it's certainly a problem. Phoned up my local yamaha dealer. A new one is 260 and they have to order it from Japan so it's gonna be like 3 to 4 weeks. Just wondering if there's a way to repair the hole. I know silicone won't work, gasoline will just eat it. Or do you guys know where to find a new diaphragm for cheaper?

Any help would be much appreciated!
 
I think Mikes has them for 99 dollars.

I have heard of people fixing them but not sure how. I may have one floating in a box of parts as I saw one somewhere.
 
The diaphragms are most certainly NOT related to the bike stalling. The diaphragms are only in play above (approximately) 1/2 throttle and 4000 RPM.

The JBM diaphragms are good. Just be sure to use a tiny drop of super glue to secure them to the slides. Without the glue, the slides can rotate and this will cause performance issues.

I'd suggest cleaning the pilot screw and pilot jet circuits, passages, etc. very thoroughly. Also check the valve clearances, correct any vacuum leaks, sync the carbs and set the idle mixture ONLY when the engine has been fully warmed up by riding briskly for 20 - 30 minutes. Fresh spark plugs cant hurt either.
 
Did manage to find some sealant that works on the diaphragm. You were right though. No affect.

I will take by the carbs apart today and inspect the pilot circuit components.

Also, don't know if this is related or not but it seems to be on my running on one cylinder at idle. Definitely hot spark there. However when the throttle is opened up the engine evens out and both cylinders start firing...

Sigh, so many issues! This bike has been a real headache.
 
Back
Top