03-04-18, 06:23 PM
If the choke made it worse it does suggest it’s rich. A blocked air filter could cause that so the new air filter is the place to start. If that doesn’t fix it the next easiest would be to check the choke plungers are all returning correctly. If they’re all good as punk said there’s a chance that the last guy lowered the retaining clip on the jet needle which raises it and allows more fuel through at part throttle. So next would be to check the position of the clip on the jet needles. I think position three on is standard.
A few other things that could cause rich running would be if someone’s put bigger jets in, if the jet needles and emulsion tubes are worn but I think that would need fairly high mileage, float heights not set right but that would probably make it run badly everywhere, o-ring under the float needle seat leaking but again that would probably make it run badly everywhere, mixture screws but they seem to be fine. I think the most likely culprits now are the air filter, choke plungers or jet needle position but hopefully the filter does the trick
A few other things that could cause rich running would be if someone’s put bigger jets in, if the jet needles and emulsion tubes are worn but I think that would need fairly high mileage, float heights not set right but that would probably make it run badly everywhere, o-ring under the float needle seat leaking but again that would probably make it run badly everywhere, mixture screws but they seem to be fine. I think the most likely culprits now are the air filter, choke plungers or jet needle position but hopefully the filter does the trick