carb tuning

[scott12544]

Hi all, just bought a 1964 ca95 that is ready for a rebuild given there are 20,000 miles on the odometer, but the engine does run, just not very good. I have rebuilt the carb twice and the bike is very hard to start cold. here is where it gets weird. If I have the carb extention tube going to the air filter, the engine bogs down and when I rev it, it only revs up about half way, if I remove the tube the engine has full power...is the carb sucking air at the gasket?

[Spokes]

It sounds like you have a blocked air filter, also check your compression as worn engines often start hard when cold.

[scott12544]

no, there is no filter on it just a tube......but I have been working on the bike since then..and dont really think it is the carb maybe there is more too it....set the valves, when I checked them they were so tight no feeler guage thin enough could fit in their....but i think they are too loose now, but was more concerned with compression then tappet noise...is exhaust pressure on the mufflers an indication of anything...before i set the valves the right exhaust had more pressure then the left and had a nice pop to it....now after I set the valves the left side has more pressure then the right...idk what the deal is....also when I was setting the intake valves the driver side right cylinder, was tight at the black T position no matter how loose i set it, rotated the crank about 180 and it was loose, the manual says nothing about this and to me it only makes sence that you would set the valves at the loosest position. another thing when thinking about the valve settings, now this might be crazy, but why would the cam open both intake valves and then, according to the manual, both exhaust valves, or is it that at the T positon either the intake or the exhaust valves are in their respective neautral positions...idk...

[Spokes]

Setting the tappets according to the manual is poorly explained. Try the following:

Remove the cam sprocket cover on the side of the cylinder head to expose the cam sprocket.

Look for the timing "O" mark.

Rotate the "O" mark to the 3:00 position. Looking at the engine from the exaust side (front)

The Right Exaust tappet and the Left Intake tappet will be loose. Set the clearence to .003

Rotate the "O" mark to the 9:00 position. Again looking at the engine from the exaust side (front)

The Left Exaust side and the Right Intake tappet will be loose. Set the clearance to .003 in.

I use this technique on my newly assembled CA95 heads before putting the engine back together.