All

I have sourced a cam shaft from Sepp. Thanks to those that have been looking for me.

For those that would like to know: I rebuilt my engines. I fitted barrels, pistons, crankshaft and oil pump from an XV1100. I also had the bores honed so I needed to run the rings and barrels in. I intended to drive slowly for 500 miles to let in 'run in' properly.

But... I got to 308 miles and the engine made a small noise then seized. The front camshaft had welded itself to the white metal bearing. The cam sprocket had rotated off the pin. The problem was oil starvation to the front cyclinder head.

With Sepp's help and others I have all the parts on the way. I am racing to get it all done before the Rally.

Regards
Kevin

Hello Kevin,
maybe it is interesting you, that
6 years ago  the same damage happend to my engine,
in my case it was not Oil starvation to the head (as it was in your case) , it was caused by myself.  After controlling the camshaft i fixed the screw that holds the sprocket with loctite.
I did that because i thougt it was mentioned in the yamaha manual,  maybe it was not.
A bit of the glue closed the little oil-hole in the camshaft.
I went 50 Kilometers and then came that squeezy noise.
Since then i use norm -type bearings (6202 as i remember) instead of the Alloy -rings . No problem up to now.

Regards
Ali

Hello Sepp

Please see below a photo showing both sides of the cam.

When I removed the cam there was alluminium debris in the hole where the oil feed comes to the small end of the cam.

There is a lot of wear on the cam profiles.

Plus the sprocket end of the cam has welded itself to the white metal bearing.

I pulled out the oil pump and found some debris in the strainer. Not enough to block all of the oil flow but perhaps blocking 50% of the flow.

Regards
Kevin

Hello Sepp

I will do that. I normally crack the bolt  where it it feeds the oil pipes to the heads and where the oil pipes meets the heads. Just to check I have oil pressure and I have oil pressure to both heads.

I did this when I did the rebuild. I can only think that it worked OK from the rebuild but I gradually lost oil pressure as the oil pump filter collected some particles.

I am still waiting for other parts to arrive at my home and I will be going on holiday  from Friday. So when I come back I will repair the engine and let you know how I get on.

Another question. Should I change the camshaft chain? It looks to be good but a lot of force must have been on the chain when the camshaft seized.. I don't want to change the cam chain as it means taking the engine out of the bike. What is your advice?

Thanks for your help.

Kevin