idle speed

[sam0840]

Got everything back together seems to be running ok but today it seemed like it took awhile to come down to idle. I leak tested holds good. Still have tors to my knowledge carb settings r stock. Needle is at second slot from the top. Its about 50 degrees today. I really have no way of measuring idle speed just go by ear. Any advice?

 

[dirtysquared]

When you rev it, does it take awhile (hang) to come back down? Thats a sign of a lean condition. Set the air screw. 1.5 turns out from tight. What mods you have done to the motor? jets in carb?

 

[sam0840]

I don't think so. It seemed to do it after id ride for a few min and then coast to a stop with the clutch pulled. As soon as I let the clutch back out some it goes back to a normal idle even after I pull the clutch back in. I think I have a 220 main. Air screw 1.5 and needle on second slot from the top. Maybe its cold enough to put a larger main in?

 

[dirtysquared]

Stock main jet is 230. So as soon as you let the clutch out it will drop the idle to "normal" ? If you moved the clip on the needle up, that makes for a leaner mixture .

 

[sam0840]

Yes when I would put a load on the engine it would drop it down and it says down. I don't have a tach so I don't know how to set the idle speed correctly. Ive just been doing it by ear with the idle screw and the air screw. So maybe I just jacked something up. Ill check that main tomorrow. I moved the needle down the other day because it was running rich and bogging down as I went through the gears so it much more crisp now maybe I should try the middle clip position. But I know needle doesn't have much to do with idle circuit.

 

[dirtysquared]

Your right about the needle and idle. Did you give the carb a good cleaning also? Set your float levels. Check the carb boot for leaks also. Did you put a vacuum cap on the oil injector nozzle if your running premix?
Sorry if rattling a lot off, just typing what's comin to my mind.

Fred

 

[Awk08]

coming back down from lean mid throttle positions
(1/4 to 3/4 throttle = needle/clip position)
can and will create a lean condition that shows up as high idle rpm's.
lower that clip back to the middle position.
while you're in there.......

first, set/check your float height:
http://www.blasterforum.com/carburetor-138/float-heights-how-adjust-them-50565/

then set your airscrew/pilot circut.....
http://www.blasterforum.com/carburetor-138/adjusting-your-airscrew-pilot-jet-51060/

plug chop for main jetting

 

[sam0840]

Ya all that is good. I had the whole engine split to repair a leak and before I rode it did a leak test it held strong and the other day seemed to run fine. That's why I was questioning the main because since then it has cooled off from 70s to 50s. But that has nothing to do with idle either. My manual says to adjust idle with the idle screw to like 1300 rpm and then adjust the air screw to highest rpm and then adjust idle back to range with the idle screw nut there's no way of knowing where I am at just going by ear.

 

[Awk08]

Ya all that is good. I had the whole engine split to repair a leak and before I rode it did a leak test it held strong and the other day seemed to run fine. That's why I was questioning the main because since then it has cooled off from 70s to 50s. But that has nothing to do with idle either. My manual says to adjust idle with the idle screw to like 1300 rpm and then adjust the air screw to highest rpm and then adjust idle back to range with the idle screw nut there's no way of knowing where I am at just going by ear.

yeah, you can do it by ear
return the needle clip to the middle,
i jump up 2 main jet sizes for temps in the 50's down into the low 40's/high 30's
so yes, that 20 degree temp drop will require a larger main jet (especially if it's a 220 ? )
an airscrew adjustment and possibly richen the needle by dropping the clip 1 position.

 

[sam0840]

Thanks guys. Ill give it a go tomorrow and see what happens. My computer is down otherwise id try and take video of what it sounds like for you.

 

[sam0840]

Got it checked out. Had a 230 in there so that was good elevated needle one slot and then did some refinement with air screw and idle screw. Seemed to be good! I just don't ever remember it being so picky with the weather! Thanks for the help everyone

 

[dirtysquared]

Thats a small stock main, Deoending on your mods, elevation and temps, you might have to increase the main size. Throw a list of what all is done, and someone can get you close to the right main Jet size.

Fred

 

[sam0840]

Its stock. A 230 is what my manual says should be in there so I should be just fine.