Can't get alternator marks to line up for timing

[Jake Violando]

I put a new cam chain guide. I have the jugs back on and the head, I'm ready to line the cam up properly once I get the rotor mark to align with the TDC mark. Every time I get before the "T" mark it jumps past if. Even with a wrench one can not hold the rotor at the mark. Any ideas why? Worked fine before I changed the guide. I want to put this back together . The picture is the point it goes to freeely. Then it's real hard at this point, you bump it a little towards the "T" mark and it lurches right by it. Top cover is off spark plugs are out

 

[B Burdine97]

You just need a little redneck ingenuity is all.. A 17mm wrench with a hammer jammed under it just right works great. Haha

 

[B Burdine97]

Or an extra set of hands of course, but those are hard to find.

 

[Jake Violando]

I had an extra set of hands but me or my partner couldn't keep it on that fine line. The slightest bump one way or the other and the whole thing jumps. Before I took it apart it rested at the TDC mark just fine

 

[angus67]

Perhaps a piston stop would help? Maybe slack the valves off.

 

[TwoManyXS1Bs]

I'm guessing that your timing mark is about 5°-6° before TDC. That'll be about 0.007"-0.010" of piston movement before reaching top.

On a well-worn engine, I'd be thinking along the lines of "ring ridge" interference. But, since it didn't do this before your work, maybe a flake of carbon slipped down/alongside the piston, and is jamming the top ring. Or, a speck of sediment got into one of the crank's bearings, creating this resistance, but that's quite unlikely to happen just at TDC.

I wouldn't ignore this. Needs to be cleared...

 

[Bob Kelly III]

at the risk of seaming a bit simple..... try clamping a pare of vice grips to the Crank bolt instead of the wrench that way there is no "SLOP"
in the wrench.... and when it gets close you can hold the vicegrips real tight and be ready for the change in direction....
that's what I did when doing mine, and it worked fine.
.....
Bob...........

 

[Jake Violando]

I'll try the vice grips. I just want to ride..

 

[retiredgentleman]

Back off the cam chain tensioner, if you have not already done that.