has anyone removed the pilot air screws? (not the fuel screws)

T

TJ500

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Joined
May 17, 2003
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661
Location
Lockport, Manitoba. Canada
I have a strange idle on my 2002 MM700 and for the life of me, the only thing left to remove/clean are the pilot air circuits (not the fuel screws)... In my many years of owning this sled I've frequently and regularily cleaned the carbs thoroughly (excet for the pilot air screws and related circuits).. I just can't seem to get them to budge when trying to remove them and find myself afraid to force/strip them

Are these something that is regularily removed and if so, might these air circuits be contributing to a boggy idle?... Almost sounds like it's running on 2 rather than 3 (verified running on 3)... Once harder onto the throttle, the problem isn't there...

Just cleaned carbs but willing to try again if removing these air screws is possible... Fuel screws are 1.5 turns out... Jetting has been the same for the last 11 years... no mods to sled other than Tempaflo (Tempaflow has been installed 10 years and I did try bypassing it).... never a problem before this year.... fuel is fresh full tank of 91 octane.. thanks TJ...
 
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the pilot air screw is on the bottom of the carb and should be removed and the passages blown out with air. The engine runs on this circuit until about about 1/4 throttle and will cause your off idle bog.
 
01sxr700 said:
the pilot air screw is on the bottom of the carb and should be removed and the passages blown out with air. The engine runs on this circuit until about about 1/4 throttle and will cause your off idle bog.
Click to expand...

did you have any trouble removing them? they seem very tightly fitted and don't want to ruin things ...... thanks for the reply.. tj
 
the pilot air jet is in the mouth of the carb. (it seems you understand the difference between them and the fuel screws in the bottom of the carb) I dont remove them when cleaning my carbs. But when you spray carb cleaner through the pilot jet hole it should come out the air jet. I've removed them on a few carb racks without problems but I did have one a few years back that wouldnt budge and got all F'd up so thats why I dont remove them any more.
 
I had a messed up Pilot air jet one my sled when I bought it. I used a star driver that I could tap into the hole to remove it, then I replaced it. Never taken them out since. I just do what Staggs does, blow carb spray through it when I clean the carbs.
 
I check the air jets with a benda light. Send light down the particular circuit from the bowl and you should be able to clearly see through the air jets in the air horn of the carb. I have to use magnification with my eyes, but it helps give peace of mind when you can actually see it. Cleaning with carb cleaner and then compressed air like mentioned above is important. Always watch the exit points of the carb cleaner when you first hit the air of course. Make sure the cleaner comes out each port for that particular circuit. Most pilot circuits have 2 ports into the venturi as well as the fuel pickup where the pilot jet is located.

Many sleds with the VM carbs went without air jets (they just left it open). I think it was Olav Aaen who discusses this a bit in his carb book. They found that there was really no benefit to restricting the air flow. The important part is that it is open because if not the fuel will not flow like it should through that particular circuit.
 
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