Carb rebuild. I guess?

[iglehart332]

Well I just got my xs400 last week and am finding out the previous owner was an idiot. After building a new fuse box (he had the stock box rigged up with electrical tape) I got the bike running on full choke. If i moved the choke in.. it died, if i nudged the throttle.. it died. So now here I am with a disassembled carburetor and I have a few questions.

Dose this look like it needs to be replaced? the other diaphragm from the right side carb looks fine.

Another pic of the left side diaphragm

This one you can see the light through it.

The main needle jet is damaged also

This side looks good

Previous owner seemed to strip everything out. I guess he lost one of the bolts that holds the top carb cover on because I found a lager size forced in the smaller hole, destroying the threads

Anything tips for rebuilding the carbs? Things I should check, clean ect.? I cant believe those slide/ diaphragm things are like 70 bucks.

 

[Onetype]

The diaphragm does look like it should be replaced, but they arent cheap so I would try and salvage it first. You might be able to put a thin coat of silicone or some gasket goo on it. A good way to tell is to put it all back together and push the diaphragm up while holding the vent, it should drop slowly.

I had the same problem you are having when I first started mine, you need to pull everything out, and I mean everything. Then you can boil them in a pot, soak in carb dip whichever you prefer. It took me a good 5 or 6 times to get mine as clean as they needed to be.

 

[drewpy]

these guys are 7 miles from me

http://www.nrp-carbs.co.uk/yamaha_carburettor_diaphragms.htm

 

[iglehart332]

Cool. I'm hoping my local bike shop can dig up the parts. Say they got hundreds of carbs laying around and it would take them a few days to sort through them for what I need

 

[faber]

The diaphragm might be air tight, if that's the case you might be able to bring back the rubber with some armerall, the rest of it should be pulled apart and ultrasonic cleaned. Looks like the jets are in rough shape, Check the sizes (it should be labelled on the side of each jet) and verify they're correct for your bike (they look like they've been messed with a few times).

 

[faber]

Sorry I meant top of each jet for sizes, side to see if they're the real deal or not.