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can the timing be 180 degrees out?
Posted: Tue Dec 13, 2011 10:27 am
by drglamis
I just replaced the valve seals for the first time on a 04 CRF250R, and now the bike will not start. I followed the service manual for this, I did have the piston at TDC but I don't know if it was on the compression stroke. Can the timing be out 180 degrees? I am getting spark, and fuel but it doesn't sounds like it wants to start. Any suggestions
Posted: Tue Dec 13, 2011 11:37 am
by scotsy
360 degrees out is more likely = one complete rotation of the CRANKSHAFT
The crank and cam marks should be lined up and the inlet lobes of the cam will be pointing 'up' and 'rearward' when you've got it right so there will be clearance on all the valves.
This is TDC on the compression stroke
Ian
Posted: Tue Dec 13, 2011 12:07 pm
by crfsonly
welcome to CRF's Only! when at TDC intake cam lobes should be facing the rear of the bike. when checking the clearance the cam chain tensioner must be active. here's a good "how-to" check and adjust your valves on a CRF250X (same principles/process for the 250R).
http://crfsonly.com/howto/crf250x/crf-v ... stment.php
ken
Posted: Tue Dec 13, 2011 3:04 pm
by drglamis
When I put it back together it was this way. I don't know if I took it apart this way or one revolution off. It doesn't sound like it matters. I didn't check the valve gap with tension on the cam chain. so I may need to do that.
thanks for all your help