Hi,
I'm having real problems with my DS90. I have had a new battery, sperk plug, ignition coils and fuel filter. I have had the carburetor taken off and cleaned twice, but still the same problem. I can get it to start and then it just cuts out and refuses to start again. It was running last summer, but I still had a problem when I opened the throttle but nothing happened and then it just cuts out again.
It's as tough the fuel isn't getting through. I've tried blocking the 2 stroke oil pipe and filling the petrol tank with a pre mixed 2 stroke, but still have the same problem. Before I order a new carburetor, has anyone experienced the same thing and fixed the problem?
I'm getting exasperated!
Thanks
Phil

 

Does it have brake light switch? If so check see if brake light stays on could be switch stuck making the ignition system thinking brake is applied an put in limp mode

 

Hi, thanks for your response. No there are are no lights on the ATV so that cannot be the problem. I'll re-check the spark again today and if that's okay it must definitely be a fuel problem. I'm wondering if the auto choke has anything to do with it?

 

Is it hard to cold start? Is oil dripping out exhaust? If is may try running a few seconds with exhaust loose from the cylinder just to see if its plugged or soaked with oil. If hard to start may check compression first an get a gauge reading? if compression 120 or so should be fine then I would assit running with hand sprayed carb with carb cleaner an see if the problem spot gets better.

 

Thanks for your comments.
I've managed to get it going! I disconnected the auto choke cable, tightened the jubilee clip where the carb connects to the engine and covered the inlet at the air filter box with some sponge. This seems to have had the effect of drawing more 2 stroke mix into the engine, and responds to the accelerator better.
It now starts and runs reasonably well but still tends to bog down a bit. I think the carburetor needs setting up properly, so that's the next job.
I think you need to keep trying different fixes and see what works, and not to let it beat you.
Cheers
Phil

 

40 to 1 or 50 to 1 ratio with good mix should be fine

 

Thanks for all help and suggestions.
Phil