I should start by saying thanks to everyone responsible for the great amount of information in this forum. My son and I are working together on his pre-owned 500e as a summer project, and this site has been a huge help.
We finally got all the parts ordered and in for the carburetor -- o-rings etc... -- but we're having some real problems getting the diaphragm reseated. The diaphragm seems to be smaller than the groove (diameter-wise), and as we work around the rim, the part already seated gets unseated as we have to pull a little. Is this normal for the rim and the groove to be different like this? I've seen some posts (elsewhere) about diaphragms being larger than the groove because of age, but nothing about them being smaller.
Any advice would be appreciated.
Mine were a bit tight as well. Not that they didn't fit, they just need to be set in right. I actually found it's a matter of patience. I put the diaphragm lightly in place, and then very lightly and carefully run your finger around the groove a few times...like you are trying to make a whine glass hum. Takes a minute, but it will slip in there, and then just be careful putting the cover on.
This is happening due to the diaphragms drying out/shrinking/stiffening over time. If you can't get them to work right after multiple attempts, the best thing to do would be replace them.
hit them with some oil, it will help keep them alive and they should expand a little bit too. wd40 may help and wont dissolve the rubber.
Thanks for the suggestions so far. Right now I've got the rim of the diaphragm soaking in some oil, so we'll see if that makes a difference. It does look like a shrinkage problem -- the other diaphragm is much closer to the size of the groove, although still a little small.
With the diaphragm I'm having problems with, if I seat one side in the groove, the opposite side of the rim is not over the groove at all, and shifting the cap around to try to get the whole rim seated can't deal with that much of a size difference -- the unseated part of the rim just pops up into the inside of the cap instead of droppping into the groove. It's going to take a fair bit of expansion in the oil to overcome that -- I may end up having to order new ones after all if the oil doesn't work.
The mention I saw elsewhere about the diaphragm expanding with age blamed the expansion on exposure to gas fumes. Would using gasoline instead of the oil possibly be faster in trying to get the rubber to expand?
If they are that far off then Bombsquad is right, just replace them. It's the cold pool test. Little shrinkage is fine, a lot...well, it's just not fixable. :cool:
Yeah, I'm thinking that may be the case. I figure I need ~3 mm more of diameter on the diaphragm to fit easily into the groove, and if I remember my math right, that would be almost 1 cm of expansion around the rim -- doesn't seem likely. At this point, I'm hoping we can get the current diaphragms working so we can move on with the carbs, but I'm planning to order new diaphragms regardless.
http://www.ebay.com/itm/GS500-GSX600-GSX750-RF900-GSXR1100-CARB-SLIDE-DIAPHRAGM-/200799122063?pt=Motorcycles_Parts_Accessories&hash=item2ec08f728f&vxp=mtr#ht_864wt_1397
I got my diaphragms on ebay and they worked great and shipped quick.
EDIT: Post 777 with +7 Karma....interesting.
After 6-7 hours of oil, I might have gotten a very small amount of expansion, but the diaphragm is still nowhere near fitting into the groove easily. Bombsquad, thanks for the ebay link -- new diaphragms have been ordered, and hopefully we'll be back in business by Saturday. Thanks to everyone for the suggestions.
The bike is a '95, and I don't think much has ever been done to it. I can say for sure the o-rings in the carburetors were toast, so it's probably time to replace the diaphragms, anyway
I may keep trying to get the current diaphragms seated just so we can play with the carburetor adjustments until the new ones get here. I have the bulk of the oil off of the diaphragm that was soaking, but it's still oily. Assuming I can eventually get it seated, is there any problem with reassembling the carb with a diaphragm with that much oil on it, or should I try to clean the oil off with gas?