99 Suzuki DT225 misfiring/no power

[ReedvilleVaBoater]

Engine has started misfiring and running rough. I pulled the plugs and they were really gummed up. I had just replaced them back in April. I went ahead and replaced them again and checked for spark and everything looked good. But it is still not running right. So I think it is either a fuel issue or a compression issue. The fuel filter was changed in april as well.

At WOT it will only turn about 3200rpm or about 9 knots. After about 20 minutes of running like that it will start to hit on all cylinders and it will speed on up. It seems to stay that way until you stop and let the engine cool.

Any ideas? Sounds to me like low compression until it heats up and the piston expands. I haven't had a chance to check the compression yet. But last year it was good.

 

[ReedvilleVaBoater]

Re: 99 Suzuki DT225 misfiring/no power

I ran some injector cleaner through the motor and it seemed to help some. The problem is still there a little though. I cleaned the small fuel filter on the motor. There was a little trash in it but not bad. Should I clean the screen in the VST? Do I need to replace any gaskets if I do that?

At this point it seems like it is a fuel issue.

Any help if appreciated.

 

[99yam40]

Re: 99 Suzuki DT225 misfiring/no power

If you run a motor lean it will eat pistons, so fix fuel issue before running

 

[ReedvilleVaBoater]

Re: 99 Suzuki DT225 misfiring/no power

I'm still having issues after making sure that fuel is not the issue. So I pulled the plugs. They only have about 10 hours on them. The left side plugs look bad. One has water on it while the other two had some carbon on them. The right side plugs look fine.

Any ideas? Head gasket?