Is my cam chain worn out? Timing and point gaps

[Metal]

Hi y'all.
So last night I set my cam chain tension and it did need adjustment. I then adjusted my valves and then I went to do my point gaps.

When I went to set up my points I couldn't get the points to open in side the marks either side of the F. They are new points. I went to set the gap between .012" and .016" but with that gap the points wouldn't open until way past TDC. So in the hope to get the bike to even run I turned the crank to the fire position and set the gap to crack open at the right time disregarding what the gap should be at the full open position. I have no more adjustment left in my points plate making it impossible to adjust the timing.

This is my first time setting points and I have a PMA I just installed. I transferred the timing marks from the old rotor. But I feel like things are just not lining up. My only thought is the cam chain has stretched or skipped a tooth.

I could use some advice.

 

[Lasper01]

Beware that The PMA rotor Can slip on The crank and that would put The TDC Way off! Mine did that.. You need to make sure your piston is at its highest when The rotor is at TDC..

 

[Metal]

Thanks for the heads up but this is a new install and is yet to run so I know this is not my problem. But I will be sure to keep an eye out for this happening in the future.

 

[5twins]

Well, if you're absolutely sure your timing marks are correct then yes, the cam chain may be all stretched out (or possibly off a tooth). To check if it's off a tooth without taking the motor apart, pull the advance unit off and look at the locating pin hole in the end of the cam. At TDC, it should point straight up or down. Come to think of it, that's something else that could be wrong, if you didn't install the advance located correctly on that pin.

 

[Metal]

That's great advice 5twins I'm going to go check that right now.

 

[Metal]

Hi 5twins, so my advance pin is pointing up and down on TDC. I'm not sure if the advance unit has been installed correctly. This is a bike I acquired and am yet to finish the project. So what now? I'm still stuck.I have new springs installed on my advance unit.

 

[retiredgentleman]

Hi 5twins, so my advance pin is pointing up and down on TDC. I'm not sure if the advance unit has been installed correctly. This is a bike I acquired and am yet to finish the project. So what now? I'm still stuck.I have new springs installed on my advance unit.

I suggest you take the advance unit apart, so that you can see the 1 large pin on the right end of the camshaft. In my picture you will see 3 pins, 1 large and 2 small. The 2 pins are on each end of the advancer rod.

Put the engine at TDC, and aline all 3 pins so that they are straight up at 12:00 position. Then re-assemble.

 

[Metal]

OK I'll do it. Right now at TDC the pin is pointing at 6? I hope its not a indication of other bad wear.

 

[5twins]

During your motor's 4 strokes, it actually reaches TDC twice. Rotate it another 360° and the pin hole will be at 12 (straight up). It sounds like you have things assembled correctly. Like I said, at TDC the pin hole should point either straight up or straight down.

 

[Metal]

OK thanks 5twins. May be I just have a badly made set of points. They are new but not as nice as the ones I pulled out. I still can't understand why the points plate would need to be turned as far as adjustment would let it In the anti clock wise direction. Any ideas.

 

[5twins]

Well, the cam chain could be stretched. It's hard to diagnose a problem like this over the internet. If I was there looking at it, I might have a chance. I would loosen the points plate screws way up and make sure I was getting as much rotation as possible. The plate is sometimes also off center a little and that can throw the timing off.

 

[TwoManyXS1Bs]

OK thanks 5twins. May be I just have a badly made set of points. They are new but not as nice as the ones I pulled out. I still can't understand why the points plate would need to be turned as far as adjustment would let it In the anti clock wise direction. Any ideas.

Anti-clockwise? That's retarding the timing...

 

[Metal]

Then maybe its just skipped teeth?

 

[5twins]

If that hole in the end of the cam points straight up at TDC then the chain is installed (timed) correctly and not off a tooth.

 

[retiredgentleman]

Here's a pic of how the large pin on the camshaft should aline with the engine at TDC. Small pin slot shown but large pin should aline the same.

 

[Metal]

How can I tell it he chain is stretched when looking at it?