Hi,

I am new to this forum. I have been working on an 1986 4zinger60. The quad only starts with starting fluid. After it runs and cools off... I try to restart and it bogs out. It has a carb from a working pw50, new plug (the 4th plug), good spark, great compression. Any thoughts?

Thanks

 

Make sure it's getting fuel from the tank to the carb. You're not getting fuel to the engine for some reason.

 

Are you sure about the compression? The later Yam 70s were notorious for the valve clearances closing up. They would then be difficult to start.

 

I believe Fuel is getting into the carb, but I will double check. An yes, for some reason fuel isn't getting to into engine. The plug comes out dry after trying to start. Ill also measure compression.

 

since this an 2 cycle engine no value adjustment needed...but compression is important tho..What was the compression reading? also a lot of time these lil quad exhaust port and muffler gets stopped up from slow riding or too rich oil mixture..I would remove muffler from cylinder jug an try to start that way then you will know if any problem with exhaust system

 

I'm not near quad, I will have to measure compression later this week. I also removed pipe to check for any buildup. No buildup, I recall cleaning it last year. However, my buddy brought the manifold reeds to my attention. They may need to be replaced. When the bike runs, and the throttle is press and released, the bike runs as if I never let up on the throttle. So reeds stuck open or worn. Maybe this is why it has starting issues?