Dropping Idle

[JoeMaico]

I have noticed that my idle keeps dropping on my last few rides. 2016 Beta 300 with RK Head. I first noticed it probably three rides ago - when I would be pulling up to a place where we were going to stop, and the engine would die. This went on for a few times, then I turned up the idle and the problem went away. Rode yesterday, and the problem is back. So, either my idle screw is backing out – or something else is going on. Bike seems to run fine otherwise (lugging, mid-range, and top end). It has just lost the ability to idle. I will be taking the carb apart this week and be going through it – perhaps I will even buy a rebuild kit to be sure. Just wondering if there is something else that manifests itself as a dropping idle – other than carb related issues.

I saw on another site, a guy with a early model KTM 200 experiencing similar issues. Recommendation so far – is to replace the metering block (which I think is the same as the Mik Jet Block) gasket. So, all the more reason for me to just replace all of the gaskets. But if there is something else that is not carb related that could cause a dropping idle - let me know.

joe

[aj_mariner]

If you run it hard for a bit does it return to normal idle for awhile?

I agree: either too much fuel or not enough air.

[JoeMaico]

No, do not think so. I can be hard on the gas then pull clutch on a downhill section - and it would die.

joe

[aj_mariner]

I ordered a jet block gasket from http://www.jetsrus.com not too long ago to have as a ready spare. It’s a back order item and took a couple weeks to come in. Their rebuild kits don’t come with it, nor the right top gasket...remember short body.

Some things to check in the mean time:
Back bleed and renew your clutch fluid: possible clutch drag. Something I have to do every year.
It might also help to do a compression test with the carb float bowl totally drained:more information for troubleshooting.

[JoeMaico]

I ordered one from ebay. His item ID was 183606901911. It states for for PWK 36S and it includes a Jet Block gasket. Guess I will find out if it is the right one. I thought clutch drag as well - so I tried shifting to neutral on a few places to see if it made a difference - it did not. I will do a compression test and also inspect the reeds to see if any are broken. But, I would think a reed issue would be experienced throughout the range, not just at idle. But, worth checking - regardless.

joe

[aj_mariner]

I agree about the reeds, but like the jet block gasket, figured it would be felt elsewhere in the throttle. You know what they say about “assume.” Compression test would show that without having to disassemble too much. I always do mine around 70degF.

[Hyde]

Mine was doing that this winter but it was also hard to start, turned out to be a little sliver of crud stuck down in the pilot jet.

[aj_mariner]

Joe, did this get resolved?