YTM 225 Help

[splangeland]

I've got a 1984 YTM 225DX that I've been having issues with. Sometimes when you try and ride it, the thing will run great with lots of power. Sometimes it runs like absolute crap! There will be no power whatsoever and when you are really trying to get on the gas it sounds kind of wet fart-ish, and doesn't seem to ever really max out in the rpm's. This can happen all in a span of riding, heck sometimes without taking your thumb of the throttle. It will feel really bogged down with no power then all of a sudden shoot off and be doing great then right back to no power. I have cleaned this carb so many times and replaced the needle and float, I also made sure all the adjustment screws were set back to factory. Can somebody please tell me why this is so intermittent. I was thinking it was a fuel problem but with it being so hit or miss I'm wondering if its a spark problem. CDI maybe? Please help this is the most frustrating thing in the world.
Thanks, Spencer

[dougspcs]

Well if it was a Honda 200, I'd say check the mechanical spark advance..but then on that machine it's all in the box(CDI).

Not that I'm very experienced on the Yamaha 225 engine common issues..but it sounds like your head is in the right place.

Of course check all the electrical basics like grounds and plugs for corrosion..clean and apply some dielectric grease to seal them.

[splangeland]

I went through and checked everything and all was good. I held my plug to the block and noticed it's not getting a nice fat blue spark so I tonight i'm going to test the coil.