Increase in power

[brettironbutt]

Good evening! I have developed a small symptom, if I am driving in town, and hold the throttle steady , it will occasionally accelerate slowly for no reason. I will start and ride steady for 10 seconds and then I get an increase in revs like I am adding throttle. Doesn’t happen all the time, I can’t be sure I am not inventing the issue. I usually ignore things for a long time, and look back and say I should have seen it coming . Asking for the wisdom of the group , if and where I might look?

[caker]

Hello! Hmmm .. shooting in the dark here, but at first think: ignition advance springs and stops, or an intermittent(?) intake leak?

-Chris

[Tinkertimejeff]

If it happens as you turn the handle bars check you cable routing and age.

[jgreen]

I think caker had the answer with an intake leak, particularly if you are holding the throttle steady.

I may be pulling this from my own a$$ here, but something is getting hot, expanding, and allowing for more air to leak in. At higher speeds, it doesn't really show as much, because you're letting in more air and fuel anyway.

If I recall correctly, you did a 500 mile break in back in October, so it's a relatively new engine rebuild. Again, pulling it from my a$$, but I recall that when you have a rebuilt motor, after 500 miles or so, you need to go through and re-torque all nuts and bolts. In this case, I'd really focus on the cylinder base on the engine case and the bolts attaching the heads to the cylinders, and tighten the bolts holding the carbs on to the heads. Then, when the engine is warmed up, you can test by spraying wd40 at all of the joints, and seeing if it affects the idle speed. if it does, there's your leak.

[Daves79x]

A sticking throttle slide will give you that sensation as well.

Dave

[sherman980]

If the revs increase but your speed does not.... Check for a slipping clutch....
Just a thought.

Chuck S.