replacement carb diaphragms

VMAX  Forum

Help Support VMAX Forum:

This site may earn a commission from merchant affiliate links, including eBay, Amazon, and others.

user 16790

Well-Known Member
Joined
May 18, 2019
Messages
638
Reaction score
407
ok I just took my diaphragms and slides out to perform the 'shotgun' and found that all of the diaphragms are starting to split/perish at the point where they are clamped in,
is there a fix for this or are new ones needed, if so has anyone used aftermarket items instaed of yamaha ones, there is a massive difference in price, are aftermarket ones ok,
I can get them here
https://www.wemoto.com/bikes/yamaha/vmx_1200_v-max/91/picture/carburettor_diaphragm
I am in the UK and bike is a USA 1991 model
 
I have been given a set of carbs for spares and the diaphragms seem to be in good condition, but the slide body is loose and the rubbers fall off, is there a good adhesive that sticks them back together,
the other thing I noticed is the needles on the 'spare' set are all about a millimeter shorter than mine, could that be UK ones against my USA ones
 
I picked up a set of diaphragms for a lick under $100 on Ebay, they were manufactured and came out of the UK. He got them stateside quite fast so I cant imagine you would have to wait long. Really happy with them and compared to OEM the price was right.
 
that's great thanks but what type of adhesive is needed to stick them all back together
 
He fusses w/it quite a bit, but it appears to finally seat properly. I'd say, it sure beats grinding off the flange holding the white plastic ring, and then epoxying on the replacement, and the plastic ring again.
 
that's a good video showing an option of replacing,
so now do I try to remove my disintegrating ones and replace the better ones in this manner or do I try some kind of adhesive to stick the slides back together on the ones from the spare set, hmm decisions,
does anyone know if the retainer part is glued into the slide from new or are they just a tight press fit, if they are a press fit then what makes them become loose ? :confused:
 
While travelling in Mexico, I had some really crazy running issues with my VMax. Every day was a different problem and was very hard to track the problems such as starting, backfiring and rough running. My good friend and mechanic,70-year old Nicho in Mexico City sprayed some water on the headers and found only 1 cylinder was running correctly. Looked at the diaphragms and found 3 of 4 had holes in them. He came up with a solution. He made a small mixture of crazy glue and baking soda which he then covered the holes using a toothpick to apply it. Then he applied a straight drop of crazy glue on top of the repair mixture and we let it cure .. didn't take long. Put the diaphragms back on and drove it without any further problems for about 6 weeks until I received the 4 new diaphragms I had ordered. I have also heard plasti-dip works but haven't had the opportunity to try it. Old school mechanics rule. Do what you gotta do to get the job done and back on the road.
 
...all of the diaphragms are starting to split/perish at the point where they are clamped in,...
While you have the slides out, check the part of the carb casting that is just to the inside of the groove where the rubbers lock in (the flared area.) Mine were extremely rough and movement of the rubber (silicone) against the rough surface, chafed them until small holes worn through. Take a piece of 800 grit emery paper and smooth the roughness before you reassemble them or you will have the same problem.
 
Follow the video, I did mine just that way using WD40 and a putty knife. I had to spend a few extra minutes making sure they were all seated properly and just for fun I clocked my slides so the slide hole was in the same position as they came out. Not sure how critical that is but I'm OCD as hell, I had no choice haha.

The seller in the Ebay link posted above by mabdcmb is the same seller I used back in 2017. Back then I asked the seller specifically where they were made and he said they were made right there in the UK by him (IIRC). I needed to make sure I was not going to end up sticking substandard Chinese parts on my cherished scoot.

If I were going to buy a set today I would message the seller and make sure these are still made in the UK, and also that they are correct for your bike as he sells a few different versions for Yamaha Vmax and Venture. When I asked him he responded very quickly , and shipped very quickly.
 
thank you every one for your advice and ideas, I have now done them by using the good ones from the spare set I was given, I did them as in the video but used engine oil as we have no wd40, I also made sure I got the holes lined up as best I could to the way they were, just in case :D, the diaphragms were a little small as in shrunk but they seem to work ok after a rainy test ride,
I like the info about the rough edges in the carbs as I would never think of that, the ones I took out showed daylight through at those edges, so when I get round to painting everything I will smooth them down (hopefully the diaphragms will have stretched to normal size by then)
 
Back
Top