cam help

[vwbull23]

Ok so here what I did I have 73 tx650 motor with all the 256 trans part the 447 crank a 700 kit in in the 457 jugs and the 447 cam I didn't know that their was such a difference in the cam lobe size I not sure if I f ed my self. where should I set the valve at ?

I had the bike running for a couple day then it now will start up sometimes then die I just clean the carbs out completely new fuel filter gas tank full. I have a pma with a Pamco kit running no battery please help thankyou

 

[grizld1]

Lift is about the same for 447 and 256 cams, but timing differs. Recommended valve lash for the 256 cam is .006" intake, .012" exhaust, but you have quite a bit of leeway there.

2:1 ratio must be maintained between crank sprocket and cam sprocket. Early motors (XS1 through TX650) used a 17T crank sprocket and 34T cam sprocket, and later motors used an 18/36 combination. Since your motor hasn't locked up, I assume that you've installed a 36T sprocket on the 256 camshaft. Was the cam degreed in correctly with dial indicator and degree wheel? If the sprocket was just pressed on any old way and the camshaft then aligned to the marks, you could have enough valve timing error to cause grief.

 

[vwbull23]

I'm running the 447 crank and cam So i the vavles set at .002 intake and .004 exhaust. Ive look over eve thing again all my electronic seem to be good I testing them with a voltmeter the bike is charging. it will run for a little then die out while running then won't start for a while

 

[vwbull23]

I did a compression test both cylinder right around 159 after 4 kicks

 

[azman857]

Will it run with the gas cap loose? Next time it dies on the run open the cap and listen for a sucking sound when you open the cap and/or if it will start up.

 

[grizld1]

Sorry, vw, I misread. Valve lash at .002 and .004 is fine with the 447 cam. Azman has probably nailed it.

 

[Marlin72xs]

I'm running the 447 crank and cam So i the vavles set at .002 intake and .004 exhaust. Ive look over eve thing again all my electronic seem to be good I testing them with a voltmeter the bike is charging. it will run for a little then die out while running then won't start for a while

Did u ever solve your problem? How? Just curious.