idle drop

Hey guys...I have cleaned my carbs twice also just recently because everyone is saying if you have lean idol,carbs are dirty.Went thru them and they are spotless both times. I have 42.5 pilots and set 2.5 turns out.The idle was not so bad yesterday,was coming down not bad.Today is acolder day and I will find out what happens. Ckecked plugs last night and they are a perfect cardboard brown right across. Even my SXR600 this year is having idle issues and never did before this season. I run my sleds hard and still not blowing anything up,but I shouldn't speak so soon...lol. Both the 600SXR and 700SRX show stock pilots at 42.5. They are 2 different sized motors..why would they have same stock pilots.You would think the 700 should be using larger pilots like 45's.I think I will be looking to get 2 sets of 45 pilots then .
 
Strange but true.In the Yamaha Specs for 2002 as an example:

02 SRX 700......................42.5 pilots at 1 1/8 turns out fuel screws
02 Viper 700 ................45 pilots at 1 7/8 turns out fuel screws
02 SXR 600 ....................42.5 pilots at 2 turns out fuel screws


why Viper at 45 pilots and SRX at 42.5 which is the same as 600.
 
I did the holes in the shelf and air box lid. It would go from fine to pig rich, to lean in about a 10 degree temp swing. It went from starting on 1 maybe 2 pulls to 10 or 12. I just didn't like it for sea level ridding. Now at 10000 ft maybe it would be fine. I covered the holes with duct tape one day, and it was back to the same good runner it was before. Maxdlx
 
thanks will try that because everything else is stock and the screws ar at 1 1/8 now so i will go to 1 1/2 see what that does ,and yes carb are all clean just done


dave
 
Yeah my carbs are squeaky clean and the pilots are stock and are about 2.5 turns out!!!!!!!!! It only hangs for about 5-10 seconds!!!
 
Don't mean to but in on this thread but here goes. Cleaned & reinstalled 147.5 pilots & carbs now. Air screws were at 2 1/8 out. Turned them out to 2 1/2. Still hangs at 4000 for about 10 to 15 seconds when run hard to moderate. It's 17 degrees here. I turned the carb heaters on and it does not hang nearly as long or as often. Sometimes not at all. Checked Plugs, They are very light tan when run at about 1/8 throttle for about 1/3 mile steady about 10 to 15 MPH then killed. They are fine for this temp but sub zero concerns me. Carb heater did not change color of plugs. I originally went up to the 147.5 pilots because it would backfire once in a while when it was shut off and that seems to have cured it. I'm with you Moparules in the fact that I can't believe the porting will change the jetting that much but I guess I'm going to have to get some 150 pilots to try. The gas here is 10% ethonol so maybe that has something to do with it.I use 93 octane. It runs great. I just want to be safe. Also Concerned about potential mpg drop. The 147.5s did not seem to effect it. Still 12 to 15
 
unscrew your pilot screw till it stop no more than 2 turn before it start to be critical for a lost needle screw...if it don't solved problem jump to next pilot size jet
 
your lucky guy on mind i try to lean it lollll...plug are haft brown haft black on 1/4 throttle
 
dave carpenter, did 1-1/2 turns not help any?

blue monster, the slide cutaway has a play in how big or small of pilot is used.

BornYamaha, try the 50 pilots @ 2 turns, and raise the needles 1/2 clip (1 washer on top and bottom of the clip, have clip in middle groove). i noticed on the ported vipers, raising the needles helps. the ethanol fuel will have an effect. service manual says to up the main jets 1-2 sizes if using ethanol or oxygenated fuels. maybe try shimming up the needles 1/2 clip too.

for everyone wondering about the hanging idle....as your throttle slides wear (due to higher mileage), they will alow air to squeek by on the sides too, and not only just underneath along the cutaway, which causes lean low ends, throttle bogs, hanging idles, etc. guys, check for wear on your throttle slides.
 
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thanks for the tips i should have checked that when i had them out... oh well do it again i guess, are they replaceable or does it require new carbs
 
please explain

mopar..if that is true what you said about slide wear..there is no way to replace parts for that.You would have to buy complete new carbs then.So explain to me how exactly the pilot jets actually work . If one goes to a bigger size,they supply more fuel on bottom end to mix with more incoming air.So in other words,with more slide wear=moreair=more fuel required.Is this what I am sensing.
 
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