I have a bomb ds650 that cranks but won't start. I was told it could be the valve clearance, so I checked it and fixed it. I had zero clerance on one of the intake valves. It now is to specs.

It cranks. I sprayed starter fluid directly into the carb. It runs weakly for for 5 seconds or so till it burns the starter fluid.. There is fuel in the bowl. If I choke it, it sputters a few times and quits.

Don't have the correct fitting for my compression guage.

If it runs on started fluid, can it still be plugs. They have been replaced twice in the last year because hard starting. Didn't seem to solve the problem.

There is spark. I don''t really know what a good spark looks like.

A little history. It has a high compression piston and runs quite poorly on premium auto gas so I run $8/galon racing fuel.

Have you got any suggestions?

 

sorry for the last response, but kinda sounds like the carb to me, i would do a good carb cleaning, also the ds will crank but not start if the battery doesnt have a good charge on it....hope this helps.....not alot of folks on here for the ds ive noticed

 

Make sure the carburetor has a good supply of gas going to it. Then, clean the carb.

 

sounds like one of your main jets is clogged. Remove the carb, and take it all apart, and remove all the jets. there should be two. the main, and the secondary.

 

The DS650 Needs alot of juice to turn over, the battery could be low. Jump it from a car battery and see if it starts. (note: car does not need to be running) Just use the battery to help it start.

But it could be nuber of things. Always start with the easy things before you dig into it.

 

Try re-setting your idle screw.

If its out by too much it won't deliver enough fuel to start the quad