Cam alingment ???

[spindle]

You folks have helped me tons of times just by using the search. Couldn't really find anything on this one.
When I was checking my valves I noticed for example that the no 4 exhaust and no 1 intake lobes were both pointing up at the same time. No surprise there. My questions is that they don't line up exactly, you check no 4 and have to turn the crank a little further before you can check no 1. Should they be in perfect sync?

Thanks,

[Nessism]

It's important to have the cams in the proper position before checking the valve clearance or the adjacent cam lobe can skew the clearance in the journal clearance. It's not good enough to just point the lobe away from the valve bucket.

When checking the exhaust valves you want the exhaust lobe pointing forward - parallel to the gasket surface on the top of the head.

#1 exhaust lobe facing forward: adjust #1 and #2 exhaust valves
#4 exhaust lobe facing forward: adjust #3 and #4 exhaust valves

Intakes are different, you want the lobe pointing straight up - at 90 degrees to the gasket surface.

#1 intake pointing up: adjust #1 and #2 intake valves
#4 intake pointing up: adjust #3 and #4 intake valves

Sorry this doesn't answer your question, hope it helps anyway.

Good luck.

.

[rphillips]

If it's like the ones I've worked on, align the notches, on the right ends of both of the cams. Both notches pointing straight in, towards each other & even with gasket surface, you can check half of the valves. Turn the notches straight away from each other & even with that gasket surface to check the other half of them. No the lobes won't be pointing at the same angles, cam timing for exaust cam is totally different, in relation to top dead center, than intake cam. Someone please correct me if I'm wrong.

[trippivot]

how do your 1-2-3 cam shaft sprocket timing marks line up when you are at t.d.c. #1 compression? the bike will run if it is 1 tooth off of either one or both cam sprockets. the big give away is very low vacuum when sync-ing carbs or low performance and hard starting. you need to be off 2 or more to bend valves.


Simply, the cam lobes point away from each other on #1 at the same the lobes point towards each other on #4 and vice versa every 360 crankshaft degrees in rotating order the int-1 and ex-4 should be symmetrical same as 2-3 alternating int-ex lift event. every other crank revolution (720deg)

[Nessism]

If you are trying to make sure the timming is right, the procedure is:

- Get #1 piston at TDC and align the 1.4 "T" mark on the crank with the mark on the case

- With the crank aligned this way, the #1 mark on the exhaust cam sprocket should point forward parallel to the gasket surface.

- Next count the pins on the cam chain between the #2 mark on the exhaust cam and the #3 mark on the intake cam - there should be 20 pins counting the first pin above #2 as 1 and ending with the pin above the #3 mark as 20.

Hope this helps.