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15 prolite 940 now 950 runs like crap

C
Nov 8, 2015
32
5
8
Ok little background bought sled 2 months ago from a guy in WA was a 940 with 156 miles. Took it out first day within mile pickup it seized. Went through BDX purchased new top end 950 per their recommendation. Had installed by cat dealer. Picked up tookout first ride bebopped up the trail for about 8 miles started working into the throttle and was not opening up possibly running on one cylinder. So towed back to pickup took to cat they tested stator, ecm and checked reeds and all checked out good. Unplugged powercomander and said it ran better and relocated ground. Said it was good and can't find anything wrong. Took out today seemed to run decent but has a terrible bog in midrange and sounds like hell. If I keep hammering thorottle it pulls hard and runs good. If I hold mid for more than 10-15 seconds it's starts running like ****. Brought it home tore pipe off pulled plugs mag side look pretty good lots of oil, which is to be expected running first tank a 32:1. PTO side look almost unburnt and wet. Which is what I noticed before I took to cat the second time as well. So as far as my knowledge goes if it were coil it would give a code and I replaced injectors from different sled with no change. I'm looking for any advise as cat has no idea and BDX has not come up with a solution either. Also put compression gauge on pto side is about 124 and mag side is about 115 guessing this could be from rings not being seated all the way is this possible. Adding pictures of plugs and write up from cat. Thanks in advance

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nosajlleb

Well-known member
Feb 19, 2010
708
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Michigan
Did BDX supply you a tune for that 950 for your PCV? You should've kept the 940 and got a hold of Kevin at Hub's performance, he's the master of that BB. BDX will be of no help, I've got personal experience in asking for help from them with just a shoulder shrug for an answer. Also, which Throttle bodies do you have? 50mm or 52mm. Unfortunately your going to have to deal with SSI/BDX to get this right. Start by getting a tune for the 950 from them.
 

richardderkevorkian

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Feb 7, 2010
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Soldotna AK
Yes I have their "spot" on tune for the 950 they are 50mm thorottle bodies. I've noticed the shrugging of the shoulder lately.

I would check your tps settings. Whoever installed the TPS on the new throttle bodies probably set it wrong. I would venture to guess that was the cause of your first seizure.
 
C
Nov 8, 2015
32
5
8
I would check your tps settings. Whoever installed the TPS on the new throttle bodies probably set it wrong. I would venture to guess that was the cause of your first seizure.

That's an interesting thought, are both cylinders separate or the same setting? As it clearly running on one cylinder. I ran it again today briefly and runs ok if ya stab the throttle, but if ya ease into it it spits sputters and runs on one cylinder. I have video if anybody wants to hear it, just can't upload it.
 

richardderkevorkian

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Feb 7, 2010
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It is one tps for both throttle bodies. It will not run well if it's not adjusted properly. I can't believe a shop, and ssi hasn't mentioned that to you. That would be the first place I'd look especially since someone had to install that tps on those throttle bodies, they don't come assembled. They also don't come in sync so when you should make sure both butterflys are adjusted the same
 
C
Nov 8, 2015
32
5
8
Ok idk if it Means anything but I did have somebody pull the thorottle and both appear in sync. Idk how sensitive they are but that's my observation. How do you test check to ensure they are in synce?

It is one tps for both throttle bodies. It will not run well if it's not adjusted properly. I can't believe a shop, and ssi hasn't mentioned that to you. That would be the first place I'd look especially since someone had to install that tps on those throttle bodies, they don't come assembled. They also don't come in sync so when you should make sure both butterflys are adjusted the same
 
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nosajlleb

Well-known member
Feb 19, 2010
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Yes you can plug a computer into your PCV and with the PCV program you can alter the voltage on your tps. I've done it with a long Phillips screwdriver and my laptop.
 

richardderkevorkian

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I wouldn't recommend that. The tps is supposed to be set with the throttle bodies all the way closed, idle screw backed off all the way. Then you set the idle once the tps screws are tightened.
 

Thunder101

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Feb 7, 2008
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As said check your tps to make sure it is set right, then get a a/f gauge set up. I like the afx by ngk it has a big digital display. If your mid range rpm is in the 13's and wot is 11.5 to 12 it will run well. How much timing advance has been added ?
 

BlueDevil

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Oct 19, 2013
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I agree bdx will be no help. And like mentioned above get ahold of Kevin he will make it run. Has the bottom end ever been apart?
 
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nosajlleb

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Feb 19, 2010
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I wouldn't recommend that. The tps is supposed to be set with the throttle bodies all the way closed, idle screw backed off all the way. Then you set the idle once the tps screws are tightened.

Done it several times with Kevin at Hubs walking me through it. Although my TPS was never the problem but setting the voltage was quite easy while idling. If BDX would've loaded the tune in the $18k sled I bought from them I would've never been even looking at it. FWIW
 
S
Nov 26, 2007
1,403
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utah
I had a '14 with the 940 and had exactly the same symptoms as you, sympathize greatly....tried many programs on the PC, kevin tried many things and I have lots of tuning experience....did everything I knew, never helped...sold sled to guy who knew all the problems, sled died a mile off his truck, he replaced the stator, ran all this year with no problems....go figure...:face-icon-small-sad
 
C
Nov 8, 2015
32
5
8
Did the sled ever run good with the 940 on it?

Not for me. The 940 seized half mile from my pickup on the first ride after I bought it at 156 miles on the sled. I now has a 950. The guy I bought the sled said there was not a thing wrong with it when I bought it but I know different now haha.
 
C
Nov 8, 2015
32
5
8
I had a '14 with the 940 and had exactly the same symptoms as you, sympathize greatly....tried many programs on the PC, kevin tried many things and I have lots of tuning experience....did everything I knew, never helped...sold sled to guy who knew all the problems, sled died a mile off his truck, he replaced the stator, ran all this year with no problems....go figure...:face-icon-small-sad

Interesting as arctic cat tested it and said mine was good, but I know well enough it could very well be the issue. Thanks for the tip
 

Thunder101

Well-known member
Premium Member
Feb 7, 2008
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Variables in every sled.
fuel pressure
▶️⏺ ECU
Some are just rich
Some have less timing.some more
If you add 100 plus cc and have not added timing
And a bit rich yes you could be fouling plugs.
As for the guy that had a bad stator that can be
Tough to diagnose, did one this year and I was
50/50 if that was the problem. Pretty much a guess.

I don't have a 950 but I'm sure it will run great once
Tuned.
 
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