CAM Chain Slipped
Posted July 26, 2011 - 04:06 PM
I have set it at TDC based on the "I" mark on the flywheel, set the dot on the intake cam level to the head, put in the exhaust cam with 13 chain pins between exhaust and intake cam, put it all back together and nothing. I have done this so many times now that I am frustrated and pissed and it takes me a lot to get to that point.
The exhaust cam marks seem to be a little clockwise, not even a full tooth and if I rotated it, it would be at 12 teeth.
It wont start, occassionally it will back fire if when I hit the E Start button but it will mostly just turn over with nothing.
It has spark and it has fuel. Am I overlooking anything?
Posted July 26, 2011 - 04:43 PM
Posted July 26, 2011 - 05:01 PM
Posted July 26, 2011 - 11:20 PM
This is all according to several threads on TT plus my manual. Buttoned it up and tried starting it with only a couple of back fires.
I rechecked my valve clearances and the intakes were at ,04 and should be between .1 and .15 and the exhaust valves were at .16 and should be between .20 and .25
If I turn it over by hand it seems to be lacking compression compared to my own WR. Could the clearances be so tight that the Valves are not closing all the way? The owner is headed to the dealer for some shims in the morning so we can get the valves within spec.
Posted July 27, 2011 - 07:09 AM
Posted July 27, 2011 - 07:23 AM
Posted July 27, 2011 - 07:33 AM
TDC is the single line past the 'H' mark. At 13 pins, all the marks should line up with the chain tensioned.
At 0.04, your intakes are way tight. At 0.16, your exhaust is getting there too.
The dot on the YZ exhaust cam should also line up.
If there is a measurable clearance, it should start.
Posted July 27, 2011 - 10:07 AM
I have done this on my own bike and others litterally twenty times with no issues.
You can see that the marks are really pretty close.
I can't get a picture of the "l" mark of TDC but you can kind of see it here. It is a little to the right by just a nats ass. If I rotate it a smidge to line up perfectly the dots on the cams should be pretty close.
Does it look right to you? It does to me. It just wont fire for me. I hope by getting the valves adjusted properly it will work. Any thoughts?
Posted July 27, 2011 - 03:06 PM
I removed the exhaust caps, changed my shims and then bolted everything back together, removed the intake cam and found it difficult to get the cam cover off. Went to remove the little caps and couldn't get them off. Upon further inspection you can see where the cam journals got hot and reamed them out some. Long storey short is a new head, intake cam, etc., etc..
Anyone have a new head and WR intake cam and accessories for sale? Perfect time to go through the engine.
PM me what you have and how much.
Posted July 27, 2011 - 08:38 PM
I've heard that the journals can be repaired, but I haven't pursued it. I took the opportunity to go ahead and replace the piston and timing chain while I had it apart. My intent was to go ahead and sell it after I got it running again, but it runs so good now I can't part with it.
Posted July 28, 2011 - 06:28 AM
Posted August 04, 2011 - 11:11 AM
What year bike is it?
Keep in mind that when you change cams you HAVE to re-shim the valves.
Too tight valves will do nothing but backfire all day long!!
Posted August 04, 2011 - 11:12 AM
Does anyone know of a shop that can fix this head and repair these journals?
Engine Dymanics in CA fixed my WR cam journals.
Call Mike Crowthers
Edited by R_Little, August 05, 2011 - 05:59 AM.