Unexplained Drop in Idle Speed

Energy One
MTSCMike

MTSCMike

Member
I took my 06 Pitbull in to the local custom shop for a new jackshaft seal to fix the leak that my (not so local) BD Dealer never could. All he did was replace the seal and tighten the top cover on the tranny which had started to loosen a little. NO MORE DRIPS :)

When I picked it up I immediately noticed a drop of probably 200-300 rpm in idle speed. It sounded like one of those older Harleys that have been idled down til they sound like the next stroke may be their last :eek: . I called the shop and he says he didn't touch anything that wasn't directly related to the leak and I believe him. He's anal like me.

The rpm lights never dropped to 500 when I let it idle without any throttle help but they did go a little crazy by flashing all around like they were making laps around the speedo. The idle mix was just like it's been for 2 years and so far as I can tell the idle speed screw has never moved in all that time. It took about a 1/4 turn on the idle speed screw to get the idle speed back to the level I'm used to hearing.

Three questions:

Are the flashing rpm lights a normal low idle warning or do they mean something else?

Has anybody ever had a BD change idle like this and if so why?

Is this some sign of impending doom?

Inquiring minds want to know...I think :(
 
G

Gas Man

Cool isn't cheap
Calendar Participant
Just adjust your carb all over again from the begining as described in my how to thread. It is possible that the spring on the idle screw is just a little loose. You could remove, pull the spring a bit to re-add in some tension and then adjust the carb. just count the turns out so you have a desent place to start.

The flashing rpm is a warning of low idle... you don't want a low idle cause anything under 1k your oil pump don't pump much which is obviously bad.
 
MTSCMike

MTSCMike

Member
Thanks, Gas.

I already knew about the need for at least 1000 rpm and I have a printed copy of the shorty carb adjustment instructions you link in the how to section. I was just surprised that it happened so abruptly.

I'll keep an eye on it. Sure is nice to have no leaks. I could get used to that!
 
Raywood

Raywood

The Pirate
Staff member
Calendar Participant
Troop Supporter
Mike, the flashing lights come on at less than 950 rpm as a warning to throttle up. I would guess your mechanic adjusted it but you never know!

:cheers: :cheers:
 
dogvet

dogvet

Banned
A change in idle especially idle dropping is a bit unusual (the idle will drop some after the engine is up to temperature). Erratic or hiogh idle speeds would indicate a possible intake leak. I would suspect that the idle speed screw has either moved or been moved. Since the only thing that keeps the idle speed and accelerator pump screws in place is a little spring, the screw may have shifted on it's own (perhaps the spring has become weak.

You could put a drop of paint or nail polish on the screw(s) just for a visual reference to see if things are changing over time. I have seen these settings move over time.

I wouldn't think a drop in idle speed is a sign of impending doom, but be aware of any further changes in engine sounds or performance.

Have you checked you air filter?
 
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