Vintage Dirt Bike Q & A

I am rebuilding my '74 CR250 and a couple things came up.

1- Clutch had 7 fiber and 7 metal plates. OEM manual shows 7 and 6 and that is what makes sence to me. I never put metal to metal (alum) as was the case here with the 7th metal plate next to the pressure plate. Is there a reason for this or an oversight on the last mechanic? I have noticed that when I use/abuse the clutch it slips after about 4 turns but if I ride easily for a lap or so the clutch no longer slips. The pressure plate showed no excessive wear.

2- Engine had no center gasket. I put in a complete '76 gear set (it had a '76 gear set in already) and without the gasket the shift drum got pinched too tightly to move when I put it back together. I understand the principal behind squishing the crank and crankcase... but was this to save money or a hot setup?

3- 6mm studs on top of the cyclinder are stripped. Has anyone pulled these out? I figure I will use a propane torch and heat the alum around the studs and have a go at it. Is there any reason to not put bolts in, instead of studs?

Thanks,
Rick Distler

I would put the bike back together using stock parts and the way the mannual says on the studs in the head use vise grips and turn them out. i would put studs back in the head.

Hi Rick,

Sounds like some "gerbil" assembled the clutch previously - I don't recall ever seeing metal to metal.

Put the proper centre gasket back in - Honda Engineers designed the engine to have it and you'll end up binding things up because of the close tolerances if you leave the gasket out.

If you are going to put heat on the magnesium side casings in order to remove the studs, be careful not to apply too much of the hot stuff or you'll stuff the casings.
"Hot to touch" (but not "Hot enough to fry") temperatures should release any "Locktite" or other locking agent the previous person used.

Ray

Hey Rick, I'm also just finishing up restoring a 74 Elsinore 250. One of 6mm studs in the cylinder was also stripped on mine. There was enough threads at the bottom to take two M6 nuts and tighten them together on the stud. Then put your wrench on the bottom nut and turn out the stud, the top nut just acts like a jam nut while the stud is screwed out. This also works good for any other stud that isn't stripped and you don't want to mess up the threads with vise grips. Email me with any other questions, I'd like to see a pic of your bike when your done.

Matt, MI
mailto:matt_schelosky@hotmail.com