2004 st13 cold start idle very fast 2500 rpm, then rough idle

[Steve Epps]

Hello members, I have had this problem for a while and it continues even after having the bike serviced. Some times worse than others, has anyone else had a problem like this and what do you think it is? I have Delkavic mufflers and a K&N filter. Even after the bike is warm it will sometimes get a rough idle at the lights and almost stalls. Any ideas will be appreciated, regards Steve

[Brock]

Do you have the foan outer filter fitted?? There are reports that the foam causes problems..

[Neale]

Sounds like it can't breath.

[saaz]

I have a vague idea that the idle wax module may be defective, so it is not getting the right signal that the bike is warm. Also, there are some vacuum tubes that go to the throttle bodies that can clog up over time and lead to idle problems.  The throttle bodies can also be synchronised.  I am not at home at the moment so can't check my normal information. I am sure some ST13 owners might have come across this.

[Steve Epps]

Thanks for the info guys, I'll pull the tank off and have a poke around!
Steve

[StinkyPete]

Thanks for the info guys, I'll pull the tank off and have a poke around!
Steve

Hey Steve, did you find a solution?  It may help other owners.

[Steve Epps]

Gday Stinky
ended up getting the throttle bodies synched and they also cleaned all of the associated plumbing, also was due for valve adjustment (53,000K). Rides heaps better idles better at cold, seems to have done the trick. They said that the wax module may need replacing but its a $500 job, so wont be doing that unless absolutley necessary,
All the best
Steve

[Biggles]

I'd be betting it was a blockage in the throttle balance tubes that saaz alluded to.
My quick-fix has been putting a dose of injector cleaner in the tank.  While it's true no fuel flows through those lines, the highly volatile nature of the cleaner seems to clear the passages at least temporarily.
It would be interesting to hear from the mechanics, but I've never heard of the valves needing adjusting, even though it might be scheduled.  Ditto I doubt the wax module is defective.

[saaz]

The throttle bodies as such cannot be synched, but the idle circuit for getting even fast idle can be adjusted.  Seems like this issue can be placed as a sticky at the top of the ST1300 section as it might become a more common problem as the ST13s get older (like the riders!!)

[Lonerider1]

When was the fuel filter changed ??,  Mine was running alittle rough, got a new filter in and turned the old 1 upside down, was full of very fine grit / sand. Runs alot better now around town, have not yet taken it on a highway trip yet.