ran fine 2 weeks ago now runs like crap!

[Guest]

I don't get it. My 750 ran fine 2 weeks ago other than the clutch slipping a little the bike ran great. Now I took it out for a short ride last night and at 4000rpm the bike starts to breat up real bad. Seems like it is running on only 3 cylinders. No time to work on it today I am going out with the family. It will have t wait a day or two. Any suggestions?

[BentRod]

assuming nothing went bang, click or wham to signify a mechanical failure, I would say that it is an electrical fault. perhaps a coil pack has faded? or there is a short

[DimitriT]

Dirt in the carbs.

These old gas tanks produce alot of rust particles which cause the carbs
to become dirty very quickly. The tiny jets on these carbs can get partially
blocked by almost nothing.

Some will suggest running Seafoam or Chevron cleaner.

I've never found it to work as well as pulling the carbs are cleaning the idle
jet and idle mixture channel manually.

[Joe Nardy]

Yep, dirty pilot jets. I've been there several times myself............Try some fuel additive if you have the time to run a couple tanks of fuel through it but you'll likely and up pulling the carbs for cleaning.

Thanks,
Joe