Engine seems to Missfire...Need help.

[Paul RX1]

Twice this has happend. Engine seems to missfire like if I had a foul plug (running on 3 cylinders)or something. Engine idles rough and when riding engine performance is sluggish I can hardly bring up the rev's. I've stopped and turned the engine off to push the plug caps down. Start it again and it worked ok. The other time turning the engine off and on would not fix the problem so I replaced the plugs and it worked ok. I have a hard time believing a 4 stroke would foul plugs?

Anybody seen this before? By the way its a 05 Rx1 2000 miles.

Thanks

 

[grader]

those plug caps are the coils. remove them and clean them with brake cleaner. be sure to spray inside where the plug makes contact. the black dust is carbon trace and can cause missfire if its bad enough.

 

[LazyBastard]

The plugs definitely CAN foul if you leave the choke on for too long.