250es Big Red- Diagnosis

[skypilot]

Ok, here's the problem. I have an 85 honda BR that seems to run great except for a coupla minor problems. Please help me figure it out, all you trike gurus! Trike is stock except for cobra exhaust(header and muffler). I had the carb rebuilt at the local honda shop because the trike seemed to sputter and pop a lot when you let off the throttle. Rebuild seemed to help, but trike still popping a lot(is this just a cobra problem?) and the headpipe is almost completely white. Pulled and replaced spark plug, the tip was ok, but engine seems to generate a lot of heat! Is this a carb problem still, or could it be a timing issue? How do I check the timing? Can it be adjusted? Carb was rebuilt to factory specs, have new airfilter, so what is the problem? Once trike is warmed up, runs great! Thanks for any input, would like to resolve this issue without breaking the bank, since its almost Christmas time!

[cosmohawk]

I'm assuming that your carb just needs some fatter jets. Upsize your pilot and main. I can't remember how big I went on both...but the popping on decel would be a lean issue. Needs to be richened up would be my suggestion.

[skypilot]

OK, take that into consideration, can I adjust the carb to make it run richer? Assume that honda shop set it right, but could be wrong! If i can get it set right, may not need jets! By the way, tried to get them to jet it, said that it was ok like it was, was running rich, but after pipe was installed they said it was ok now? Didn't make sense, spent $$ for nothing?

[Woodsrider]

I don't think it's realistic to think that you can simply install a carb that has been rebuilt, and expect it to be adjusted perfectly for your ES(or whatever). The Honda shop would certainly set up the carb to the factory specs, but that's JUST a starting point...it should certainly be close enough to start and drive the machine, but it still needs to be fine tuned...this is normal BTW. You need to either follow the proper procedure(get a manual), or get someone else who knows what they are doing to fine tune it.

[skypilot]

Thanks, will download the 250es manuel, go from there!

[ailll1]

Since you dont have the stock exhaust, your trike will run lean with factory adjusments. Aftermarket exhaust make the engines breath better with less restriction. It means it sucks more air into the engine. So you have to compensate by going up a couple with the main jet mostly. You can tell how your trike is running by doing a plug chop. Normally, you would put a new spark plug in and, for example, if you wanna know if you main jet setting is correct, you would hold it WOT for a couples of seconds and after check the color of the spark plug. Dark black means a rich condition and gray/white means lean. You want it to be golden/brown.

Hope this helps