Clutch covers

[behindbars]

I have two Mint 400's. One is set up for MX and the other for enduro. The MX was made in May of 1974. They both have the lay down shock frame, and the enduro was made in November of 1974. I was wondering why they have different clutch covers. The MX has a larger cover. The enduro is moulded tightly around the clutch assembly and the other is not. Is the wrong cover on one of them? The MX engine numbers are 4-5500029 and the enduro is 4-5501085. One more thing....what's the best way to get varnish out of a fiberglass tank without damaging it?

[chicagojerry]

i believe the difference is more related to date of manufacture vs enduro or mx. the bigger one was an earlier model. someone will correct me if i'm wrong. also, i've had success cleaning out a tank with acetone. it did not hurt the fiberglass but i creamed it afterward to stop some leakage that was already there. if you are going to put a good paint job on the tank i would cream it first. hope that helps...    chicago jerry [8D]

[firstturn]

  I may stand corrected, but acetone will infact desolve fiberglass if enough is used.  I say thei from years of building and racing boats.  We actually used acetone to clean our hands after working fiberglass.  Understand that you need something to cut the varnish and acetone will do this and you can clean the tank with water to neutralize the process.  I use thinner and it has worked for me...Hope this helps

Ron Carbaugh

[Big Mac]

Recent experience with de-gunking a FG tank:

I got a bike that had sat for years. Must have been halfway full of pre-mix when it died, which evaporated to leave some really nasty tar-like goo in the bowels of the fibergalss tank. Kinda looked like a can of Gaska-cinch had tipped over and spilled out. I swiped the petcocks off for another project, and when the summer weather warmed up, the goo started dripping out...very ugly.

When I finally got around to restoring the tank, I put some fresh gas in it and let it sit a few days, then shook it like crazy and poured it out. Still seemed to be a thick coating in the bottom. So I poured in about 2 pints of laquer thinner and shook it around again. When I drained it, a lot of gunk came out. I rinsed it pretty fast with paint thinner so as not to melt the fiberglass from the inside (no telling). Then I rinsed out the paint thinner with a little gas. I worried that if I used a gas rinse on top of laquer thinner, I'd probably create some sort of spontaneous combustion bomb---giving the wife one more reason to complain about bikes in the garage.

Seemed to be relatively clean from what I could see by peering in. Put it on a running bike and a couple of tanks of gas later, pulled off the petcocks to see what was in the filters...a bit of flaky varnish debris came out but otherwise clean and good. No tank leaks...yeah.

[behindbars]

I tried some laquer thinner and it cleaned the goo right out. It did loosen the glass a little though. Not enough to harm anything I'm pretty sure. I'll seal it with some tank sealer before I use it though. The outer coating of gel inside the tank flaked up a bit, so I would imagine that there must be a better way to clean these tanks. I think next time I might try some C-12 race gas. Anyone ever tried this? I know that it's pretty aggresive on rubber parts......so maybe it will eat the varnish if given a little time to sit and soak. Thanks for the input all.