I live in Costa Rica. Brought 2 Dingo 250's with me last Sept. Got some dirty gas. Engine would not idle. Found the idle jet clogged. Cleaned it and blew out the rest of the carb. Now it idles good, but will not take throttle. Found that crimping the small hose coming from the small vacuum valve will change the idle and allow for throttle, but when I release the hose with the throttle on the engine bogs and and dies/backfires. Can anyone tell me how this carb works? I thought I understood SU type carbs, but this one has me fooled. I understand the elecric choke, but temp is not an issue here (does not get below 75). Engine ran very good before the dirty gas. Only has about 10-20 hours on it. Both atv's got the dirty gas. I think this problem is in the idle mixture and idle speed circuit, but what is the function of the little vacuum valve attached to the upper rear of the carb. Is this valve open or closed during idle? Need some help Please.

 

HI there. I am new to this forum but i like to read some of your posts. I also have a dingo 250 and battle with the same problem as you CRDINGO. Tell me have you sorted out you problem with the bike not wanting to take throttle?

 

It's been over 5 years. He's probably not here anymore.

 

you are probably right! Didn't look at the dates. Ma bad!!!