setting the cam chain timing...tips?

Hi,

I am trying to set to set the timing for my cam chain; I have tried several times, but after putting the tensioner back and rotating the chain, to check if the dots align when rotated back to the T-mark, I am always off a little bit...any helpful tips?

it sounded like common sense should fix it, but I got frustrated after several attempts...

Thanks.

Harold
1982 XJ650 Maxim
(I am not a mechanic and I am trying to rebuild this bike after my "Mechanic" f**ked the bike up after I took it for a routine maintenance)

 

Do you have the service manual? The whole procedure is defined in great detail and usually works out the first time.

 

being "off a little bit" is ok, as long as its not too much, possibly one eighth of an inch is ok.
mine was this far out and runs fine

stu

 

Yes thanks. That is helpful. Mine is off right about that distance, but to the right of the mark (instead of to the left in your picture). I will try again this weekend to see if i can improve it, but if not, at least yours is working though off as well.

The picture helps.

 

Yes, I have the manual and I tried hard to follow it, but my result is different. Will attempt again this weekend to see if I can improve it, otherwise I will try it as is...and see if it would work or not.

Thank you very much.

 

it could be that you need a new chain and/or sprockets to get textbook alinment.
sprocket teeth do wear and chains "stretch" rollers and pins wear

 

if you were going to change your setting you have to change it one tooth +/- , that usually puts that mark out in left field someplace

 

I ran into this problem when I was rebuilding my CB900C a few years back. The shop manual tells you to get the dots perfectly lined up... I'd look at it and it would be about as far off to the left as Bensalf's is in his pic above... I'd pull the chain off the gear (a major pia with the Honda DOC's) and would move the chain one link to the right. Would put the gear back on (an even bigger pia in the Honda DOC's) and it would be out about the same amount to the right. Since the stupid manual stated this line up needed to be balls on, I didn't want to settle for "close"... I asked around to 2 or 3 bike mechanics... they'd scratch their heads and kind of hee haw around, not really saying anything definitive. After wasting a lot of time, I finally settled on "close", and the bike ran fine. The only conclusion I could come up with was it was impossible to get the thing to line up balls on... no other adjustment other than jumping a link in either direction. (Cam chain was new OEM by the way).

 

so the only unknown would be the sprocket wear in your case

and would leave op with intake opening a little sooner
or exhaust opening a little late depending on point of view as to which mark was more important in the stroke cycle.
and when you take into account the shim tolerance its a wash maybe

but from others experience it was little or no affect for the average rider

 

Thank you. At least it's just not me struggling.... Appreciate your information

 

Yes, I suspect that the chain may be worn.

However, I will consider bensalf's and Robb's experiences, then if it works, I may change the chain on the next riding season.

Thanks for the input.

 

Is there anyway you could share the timing procedure with me? Im in the same boat and I'm new to the forum, thanks in advance!

 

As long as the cams are lined up to the timing marks on the cam caps and piston 1 and 4 are at TDC with the timing mark on the flywheel lined up everything is correct right?

 

thats the basics of it .

 

can't/shouldn't use the flywheel marks until you know their right on and you have to approach tdc going ccw and stop at tdc, no backing up. ccw only no cw

 

+1 TDC should be measured with a dowel (pencil) through the #1 sparkplug hole (or with a dial indicator if you have one). The pointer for the timing marks is adjustable, and it is possible that somone bumped or bent it before you got the bike. Most of the time they are spot-on, but never trust it until you verify.

 

i like a plastic straw myself, less chance of me getting it jammed and snapping off in there. depending on the condition of the bearings, tdc can be a quarter inch either way on the flywheel, if you go past it and back up

 

Pardon my ignorance, can you please elaborate on this process of measuring by a pencil or a plastic straw (as Polock suggested), to measure TDC. Yes, it highly possible that the pointer could be bent/bumped.

Thanks.

 

Hi. here is what I have done (my interpretation from the manual)

- set the pointer to the T mark, by rotating the crankshaft CCW.
- adjust/make sure the cam shaft dots are up and in line with the marks on the cam caps
- adjust each sprocket with the chain to line up with the bolt holes, making sure not the drag the chain hard enough to move from the T-mark
- hand tight the bolts for the sprockets, position the center chain guide
- turn the crankshaft CCW to the C-mark, then replace chain tensioner
- turn CCW by at least a complete cycle to check if the dots are still aligned when the pointer is on the T-mark
- repeat the process, if still off...

Hope this helps. Any comment is welcome as well.

Good luck to you!!!

 

when your mark is comming onto the pointer (about a inch away) drop your pencil/straw down the plug hole and get it to stand up straight, sort of, now slowly turn the crank towards the tdc mark.
the pencil should be at it's highest point right at the tdc mark. you'll have to do this several times because you kind of have to look two places at once and the straw movement near the top won't be
very much.
when you're doing this you can go back CW at least a inch then go CCW again. if you're satisfied that tdc is at the pointer, good. if not then make a mark by the ignition pickup with the tdc that you found and use that mark. you can still use the C mark for the rest of it, it's not that critical.
you're probably good where your at like Benslaf said but for your own peace of mind try one tooth in either direction and you'll see how far off it goes