spark plug question

[yamaha guy]

hey, got a quick question, i pulled the plug on my trike it was really black so i went and replaced it, and today after i was done riding i pulled the new one out and it was just as black as the old one, so does this mean its running to prime?

thanks, Cory.

[ilmoakw]

It means it's running rich and/or possibly burning oil...

[yamaha guy]

what would cause it to burn oil??

[Mr_RPM]

bad piston rings, bad valves/valve guide seals. most likely the rings or both. do a leak down test to find out for sure. if this is on an old trike and it hasent been rebuilt yet its probably time to do so. new piston with rings and check up on those valves and stem seals.

and your running rich, you could have a dirty air filter or need to jet down. somthing is causing you to have a lack of air or to much gas. but as said above, it might be that.

does your exhaust smoke???

[3wheelmecca]

Whats your premix ratio???

[Mr_RPM]

yeah, what kinda bike is this. LOL if its a 2 stroke than its a different story. give year make and model please. LOL

[3wheelmecca]

by name, I am guessing its a Tri-Moto. may be a long shot but what the heck.

[yamaha guy]

its a 85 yamaha ytm tri moto 225 dr and my exhaust only smokes out a little bit of black when rev after it been left running for a couple minutes other then that it runs fine but some times it will start idling down and then shut off, but it will start right back up

[big yeller]

adjust air/fuel mixture screw or if that dont work decrease the jet size. for the idleing down check the slide on the carb to make shure its clean.