Quote:
Originally Posted by Robby45
Looking for help on two (maybe related, maybe not) issues with an '11 300 ec.
First issue is the engine is stalling (while throttle is shut off) during hard riding especially on uphills/downhills. The idle works fine at rest although I have had to turn the idle screw in nearly all the way. My first thought was float height, but it looks to be ok. I have had this issue since the bike was new.
The second issue just started last weekend: the bike surges while the throttle is shut. Just quick short blips that while coasting with the throttle closed cause the bike to accelerate every so slightly. This started (I think)after I backed the the air screw out to 2 turns to try and get a higher idle to fix problem #1. I have enough slack in the throttle cable so I can't figure out what's happening here.
Carb set up:
175 Main
38 pilot
stock needle ???
air screw 2 turns out
not sure which model carb, but the bike is an e-start with ohlins/marz.
|
That sounds like a lean surge issue. Since I like a really crisp off-idle acceleration, I tried going as low as a 35 on the pilot and got similar symptoms. I tried a 40 pilot with as many as 2.5 turns out and the bike got blubbery off-idle. I ended up going to a 38 pilot at 1 3/4 turns and bumped the idle up a tad. I also swapped the 48 tooth rear with a 50 which enables me to ride a gear high in most situations and lug around in 2nd. This keeps you into the throttle a bit more and avoids the worst of the gurgling/blubbery part just off-idle. I'm using a JD blue needle (GasGas kit) in #3 clip, 175 main. Typical elevation is 500 ft and temps are anywhere from 45 to 65 degrees F. I think the 38 pilot is probably marginally lean and I still get a minor surge every now and then, but my plug tip is fine and anything bigger on the pilot will cause the off-idle to blubber too much for my liking.