Anyone work on XL500s?

[tkent02]

How to you set the cam timing? I picked up a free 1982 500, need to see what's wrong with the engine.

[tom203]

How to you set the cam timing? I picked up a free 1982 500, need to see what's wrong with the engine.

Well, I still got my 1973 XL-350: single cyl. Is yours a twin?

[tkent02]

No, it's a thumper. I think the valves hit the pistons a little bit, leak down shows leaky exhaust valves. Might need some new exhaust valves or maybe all four of them. Interestingly the piston looks like the intake valves hit harder than the exhausts, but it's the exhaust side that's leaking. Taking them out now. Got to love POs. The bolts that hold the sprocket on the cam were just finger tight. I'm thinking he realized his mistake in cam timing, fixed it, saw poor compression and gave up.


Odd, the valves are straight and they look fine, the stem seals are newer, but have chunks out of the sealing edge.

[tom203]

Probably skipped. My model had non auto camchain adjuster-and a rinky dinky method of pushing on chain.

[GregT]

No, it's a thumper. I think the valves hit the pistons a little bit, leak down shows leaky exhaust valves. Might need some new exhaust valves or maybe all four of them. Interestingly the piston looks like the intake valves hit harder than the exhausts, but it's the exhaust side that's leaking. Taking them out now. Got to love POs. The bolts that hold the sprocket on the cam were just finger tight. I'm thinking he realized his mistake in cam timing, fixed it, saw poor compression and gave up.


Odd, the valves are straight and they look fine, the stem seals are newer, but have chunks out of the sealing edge.

From memory, cam is "straight up" at TDC - both valves closed, two bolt flange vertical. Sounds like he's replaced the bent valves and not been kind to the stem seals doing it....

[tkent02]

Yeah, I think that's it. Read about it not having any oil filter too, so any metal being made anywhere goes through the cam bearings over and over and over... I like Suzuki's DR design better, don't really need another big single, think I might just part this one out.
Thanks for the help.

[exdirtbiker]

I know I'm late to this party, but you really want to join the "Thumpertalk" forum.
The folks over there are almost as nice as the ones around here.

http://www.thumpertalk.com/forum/14-xr600650/

[tkent02]

I was a member there a long time ago, kind of dropped it when it all turned to advertising.

I think I'm just going to part this pig out anyway.

[exdirtbiker]

If you have a really good cam shaft in that bike, you may have just won the lottery.

They were really scarce 5 years ago, and cam gets fried easily when the motor has "low oil pressure" - for any reason-.

I sold a good XR600R head for $320 a few years ago. check ebay "completed listings".

[tkent02]

Yeah, the cam and the head look perfect, rebuilt with two new valves. Lottery? I'll check.