Hi guys,

Got myself into trouble playing with idle speed and now the idle is rather erratic.
Here's what happened:

Bike was running and starting OK.My standard starting procedure is choke fully out, hit the button - it always starts on the first crank. Leave on full choke for 2-3 seconds, then push and hold choke roughly halfway for 20-30 seconds, then choke off. Idle was around 1200-1400 rpm bar on the display, solid and steady.

After riding the bike for a while I noticed that when I stop and put bike in neutral, the idle is always solid 2000 rpm and will not drop. Maybe it is as is should be, but it was sorta bugging me.

So just lately I smartly decided to "fix" it and I adjusted the idle screw by hand when bike was warmed up from 2000 rpm to around 1500-1600 rpm. All good, sounded good, continued riding.

Next day, doing the starting routine as usual (and you already guessed it) bike wouldn't start no matter what. It didn't take me very long to realize why it is happening - gave the screw a turn to increase the idle, hit the button and voila, we are in business again. After choke went in, the idle was way too high so turned it down to ~1200. Again, when warm idle settled at 2000. So I decided not to play with it anymore and leave it as is.

Then I went on two weeks business trip to US ( Hi Lotrat, been to Carlsbad, nice place). After returning home bike is giving me some serious grief. Difficult to start, 1200rpm idle goes up and down , sometimes bike will just stall. When warm, idle is also all over the show.

What the hell happened? I can't get it running like before, haven't touched anything else apart from that damned idle screw. WTF? Any ideas folks?

Cheers.

 

Besides adjusting the idle speed screw, you may need to adjust the idle mixture screw on the bottom of the carb. Start with the idle mixture screw about 2 1/2 turns out.
With the engine warmed up, adjust the idle speed to 1200-1400rpm and then adjust the idle mixture screw for the fastest idle speed. Re-adjust the idle speed screw if needed and then the idle mixture screw.

Ride on
Brewster

 

I adjust mine all the time to suit the temps and because it just changes sometimes. Nothing to worry about.

 

Yes, I adjust my idle fairly regularly also based on temps, elevation, etc. But those adjustments don't result in a poorly running machine afterwards. Besides Brewster's suggestion on idle mix screw, you may have something else going on that may be coincidental to your adjustment, such as a dirty air filter, fouling of the pilot jet, sticking float, bad fuel. As a simple approach, maybe try running some Sea Foam through it?

 

I had to adjust my idle after doing an oil change (oil-to-synthetic) same weight. It took me a few days to get it dialed back in. I think the carb is sensitive to changes.

 

Thanks all for suggestions.

If idle is temperature dependent this maybe a case as we head towards summer and 35deg C (~100F) are quite normal.

I'm starting to suspect bad fuel batch. Normally I refuel at a local station that I pass on on my commute to work, but this time I did refuel from a jerry can. It was sitting in my garage for around 2 months, normally it is used for a lawnmower. I'll try a fresh gas and see how it goes.

I would try fuel mix adjustment already, but because of carb de-icing plumbing is routed in such a silly way that it effectively blocks the already tight access I'll leave this option as a last resort.

Cheers.