G-Rand Posted October 6, 2008 Share Posted October 6, 2008 Hi Folks: New to this forum. Recently picked up a 1983 Maxim 400 in great shape and low miles, mostly for my boys to learn on. It runs well, but as we're going through it I discovered the petcock was not preventing fuel from flowing when the bike was off. Opening the petcock revealed a failed attempt to use silicone to seal the diaphragms. I have a petcock rebuild kit, with two diaphragms on the plunger, but I can't make sense of putting it back together because: 1) both diaphragms are next to each other on the plunger and look like they were meant to stay that way, but when I pulled it apart there was a diaphragm on each side of a phenolic spacer. 2) the phenolic spacer has two "pins" on each side of it, but only one side seems to line up appropriately with the vacuum inlet part of the petcock. The other pins don't seem to align anywhere on the petcock side. Any ideas?? I downloaded the xs400 manual, but didn't see anything there. I can't find a diagram or description of the vacuum side of the petcock, only the fuel switch side. Maybe I missed it? Any help is appreciated! G-Rand Link to comment Share on other sites More sharing options...
G-man Posted October 12, 2008 Share Posted October 12, 2008 ...I discovered the petcock was not preventing fuel from flowing when the bike was off... Yeh, my manual doesn't have a good draw-out of the petcock, either. I just dealt with that yesterday, actually. After stripping the petcock to bits and pieces, it turned out a sliver of something or other got in there behind the diaphragm and prevented the plunger from full seating. Is that rebuild kit meant for your petcock? If the existing diaphragms, o-ring, etc are in ok shape, see if you could just reuse them. Give 'em a good soak in fresh gas, clean em up, so forth. As for the gasket, any home center should have a wide silicone seal tape you could use to fabricate one yourself. Just cut out a center with an exacto knife, screw together the petcock, and trim off the excess. Link to comment Share on other sites More sharing options...
G-man Posted October 12, 2008 Share Posted October 12, 2008 You could find the exact petcock rebuilt kit that would fit your bike here, G. Link to comment Share on other sites More sharing options...
Recommended Posts