Rough Running at Low RPM

[BA]

When I left South Texas 4 weeks ago I put some Seafoam in the tank, ran it for a little bit, then parked it.  Went back down there last week and its running rough at low RPM now, almost like its missing on one cylinder.  It idles at 1000 rpm, but surges up to 1200 about every 10 seconds or so.  I can run it up to about 2000 rpm, and it exhibits the same surging about every 10 seconds.  When riding it with a load it hessitates a couple times until I get over 3000 RPM, then takes off like it should.  It runs fine at higher rpm's, like when I'm on the freeway.

Thought it could be bad gas or something like that, so we ran up to the next town and back (70 to 90 mph the whole way) and used up that tank of gas.  I refilled it and it still runs bad at lower RPM.  Have gone through 3 tanks of gas now - still problems at low rpm but runs fine at anything over 3500 rpm.

So what does everyone think?  Sticking float or something stuck in float valve on one of the carbs?

[John Luttrell]

One or more of your idle jets are clogged; I see a trip into the carbs in your near future. 

[Magnum Magna]

I was typing while John is posting.


I have had intermittent issues with the battery before.  One of the first things I look at is verifying the battery terminals are tight,  So while people with more technical you might as well eliminate that possibility.

[hootmon]

What John said.. IF you haven't run SeaFoam in quite a while, then the SeaFoam may have broke some trash loose.. Sounds like clogged slow jets to me.

[Jim8208]

John's right on the money. My bike was doing the same thing and took his advice. Runs great now.

[guywheatley]

The guys are probably right about you slow speed jets. HOWEVER, Robert has a point. My bike did almost exactly the same thing you're talking about a few years ago. I was dreading a trip into the carbs when  the problem got worse and it started to die on me. It wound up being a loose negative battery terminal.
I never did get into the carbs, and it runs great now.

I did keep running seafoam, and I suppose it's possible the seafoam cleared up the problem about the same time I discovered the loose terminal. Still, that's such and easy thing to check.

[John Luttrell]

^^  ^^Hey, I'd surely check this first; it's much easier than a trip into the carbs and it may save you a lot of time and frustration.