Jim,

surging is a lean condition. Dial the pump in to richen. You said that you tried it either way a turn but go in.....then maybe a little more. Another thing that may be the issue is an air leak somewhere. The DZ is less sensitive to these leaks compared to the other YS motors but it could be sucking air. Check the carb bolts, valve cover and backplate bolts for leakage....


Another thing to check is the rotor and make sure the pin (brass) is not loose. This can cause some grief. I have seen it a couple time....Don't just check the set screw...try pulling the pin out or see if the rotor is floating back and forth a little.

When re-installing the set screw rotate the pin off of the old mark. This way the set screw is grabbing fresh metal.

Another thing is most of the motors will have a double set screw....Tighten the first one up then run second screw down on top and it acts as a jam nut type of deal.

I would say I'd come up and work it out with you...but we are still not back in Colorado. No more Atlanta....been in Phoenix, AZ for about a week now. And the plan till about mid April.


Troy