Danged blown petcock vacuum seal question

Does anyone sell a rebuild kit for the petcock on a 1982 Yamaha Seca 650, non turbo of course. My new find was in the Craigslist here for a realistic $500. I test rode it, found that the #3 cylinder wasn't firing. Got it home, replaced the fouled #3 plug with a new plug and test rode it, voila 4 cylinders, wake the neighbors (it has a mac 4:1 pipe). So today I buy oil, filter and plugs, then get set to warm the bike up and change the oil, what...no spark on 3, and fuel is bubbling out the plug hole, due to not tightening it down to spec. Remember a post about leaking petcocks, so i removed the tank, checked the petcock diaphram, and it has a really nasty tear in it, problem found. Need a rebuild kit or replacement petcock. So are these are my options
1. replace said petcock with one that may be as suspect
2. Find an unobtanium rebuild kit
3. seal the vacuum diaphram i have and run it strictly on prime
4. use a non vacuum petcock
5. ???
Any answers would be appreciated, will do a search tonight, and what kind of sealant is gas resisitant if #3 is the best option.
cruzerjd

 

Rebuild kits ae available from partsnmore.com , oldbikebarn.com , crc2onlinecatalog.com.

 

cruzerjd, give this thread a read thru....

http://www.xjbikes.com/Forums/viewtopic ... build.html

 

Meh. I tried to get a quote from PartsnMore on the rebuild kit. They didn't even bother emailing back -- until I told them I was going somewhere else because they didn't seem to want my business. Then they got pissed. Tried to blame it on my webmail provider's spam filter. Funny, the second email made it through no problem...

OldBikeBarn -- tried to order from them. Sent in payment. They lost the payment, then they lost the order.

I eventually got my rebuild kit through some guy on ebay.

 

Careful on the aftermarket petcock rebuild kits.....the ones that everyone sells are not listed for the 650's for a reason....the 650's (some of them) use a slightly different design o-ring/plunger unit on the vacuum pull-off diaphram, and a slightly different spring, too. It's not clear to me whether the petcock body is the same between the 650's and All Others.....so the angle and depth of where that plunger o-ring seats may be slightly different, and therefore preclude the use of the non-650 rebuild kit on a 650. Anyone else have any insights?

I know that Some Places list the petcock rebuild kit as fitting 650's, but I know from taking enough of them apart that these differences do exist........

 

Bought the kit and 4 rebuild kits form Partsnmore. I have purchased a lot of stuff for my previous bikes, especially my Z1 through them and Z1 enterprises. Took the bike out for a little spin after resealing the diaghpram body with Gorilla Snot and making sure there were no more leaks and was quite impressed with the performance. The bike came with a Mac megaphone 4:1 and a Uni reoilable filter. I do not know if the p.o. reworked the carbs or not, but from idle to 4500 rpm's was milquetoast, then wham, 5000-9500 rpm's got a big smile on my face. Not too bad for a 40,000 mile bike that was running on 3 cylinders day before yesterday. Hope to see my kits by friday, then next weekend will o through the whole rebuild and sync process. cruzerjd