The main thing you have to remember is that the air screw is metering air, whereas a typical idle adjustment screw is metering fuel. So it works backward.
If you have the screw adjusted excessively in or out, and the pilot jet is clear, then you need to go up or down with that jet size.
$100 barn find cyclone
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400brian
- Posts: 5627
- Joined: Wed Jul 20, 2005 12:00 am
- Real Name: James T. Kirk
- Location: South Central Wisconsin
Re: $100 barn find cyclone
'09 Vintage Challenge Survivor, and I wasn't late for supper!
'10, '11, '12, '13,'14,'15,'16,'17, '18, 19, 20, 21, 22 Vintage Challenge Survivor !
72 400 restored, Father bought new in '71
73 X8 restored
'74 340 green machine
'74 X8 9 time VC finisher
'78 Spitfire in progress
2 '75 340S 1 running, one on deck
'78 LF 440 future CC clone
'73 Skiroule RTX 440, 500 mi.
Re: $100 barn find cyclone
The air screw should be turned in or out while running and find where the idle increases and smooths out the most. Then the idle set screw can be turned in or out to proper RPM. Common idle RPM is around 2600-2900. Clutch engagement should happen around 3200-3600.
1975 John Deere 800
1975 JDX8 (VC Finisher 2019)
1976 440 Cyclone (VC Finisher 2022)
1974 El Tigre 440 (Sold)
1996 Arcitc Cat 440Z
1975 JDX8 (VC Finisher 2019)
1976 440 Cyclone (VC Finisher 2022)
1974 El Tigre 440 (Sold)
1996 Arcitc Cat 440Z
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Garrett_p
- Posts: 19
- Joined: Tue Mar 30, 2021 1:14 pm
- Real Name: Garrett platt
- Location: Torrington wy
Re: $100 barn find cyclone
Thanks for the help! I got my sled out a few weeks ago, I had a problem where when you'd get on the throttle It would get high In rpm and then try to die It did a few times, then It would have more power than I could handle after about 15 min of running It. what would cause that? - Thanks! Garrett
Re: $100 barn find cyclone
What have you replaced so far? Spooling up to high RPM and then falling flat or dying sounds like the stator windings have failed, so you lost the high side of your stator. But, if it warms up and comes out of it / runs normally, not sure what's causing that. Generally the stator will fail after it gets hot.
Proper warm-up time before getting on it?
Have you replaced the crank seals? If not, running it hard will burn down a piston with likely air leaks.
Proper warm-up time before getting on it?
Have you replaced the crank seals? If not, running it hard will burn down a piston with likely air leaks.
1975 John Deere 800
1975 JDX8 (VC Finisher 2019)
1976 440 Cyclone (VC Finisher 2022)
1974 El Tigre 440 (Sold)
1996 Arcitc Cat 440Z
1975 JDX8 (VC Finisher 2019)
1976 440 Cyclone (VC Finisher 2022)
1974 El Tigre 440 (Sold)
1996 Arcitc Cat 440Z
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Garrett_p
- Posts: 19
- Joined: Tue Mar 30, 2021 1:14 pm
- Real Name: Garrett platt
- Location: Torrington wy
Re: $100 barn find cyclone
i let it warm up about 5-10 min after starting it. once it warms up it has 1/2 the power than when it's cold, like it's the stator.jep_800 wrote: ↑Fri Jan 21, 2022 12:53 pm What have you replaced so far? Spooling up to high RPM and then falling flat or dying sounds like the stator windings have failed, so you lost the high side of your stator. But, if it warms up and comes out of it / runs normally, not sure what's causing that. Generally the stator will fail after it gets hot.
Proper warm-up time before getting on it?
Have you replaced the crank seals? If not, running it hard will burn down a piston with likely air leaks.
i also did replace the seals.
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Garrett_p
- Posts: 19
- Joined: Tue Mar 30, 2021 1:14 pm
- Real Name: Garrett platt
- Location: Torrington wy
Re: $100 barn find cyclone
i got my snow mobile out today, from the long summer storage!
i ended up figuring out the spark plugs were bad causing the problem. it ran great after a new set, it actually had power
i ended up figuring out the spark plugs were bad causing the problem. it ran great after a new set, it actually had power