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Running on only one cylinder.

D

Danbot

Well-known member
Nov 29, 2007
1,696
967
113
Alberta, Canada
Tested the fuel pressure myself, and it was about 62 psi and remained there even when the mag cylinder quits.
Anyone have a good used yellow mag injector they want to sell me? Should I try to get both injectors? I really don't want to buy new ones...over $400!

Before you spend any money on injectors, swap yours side to side. If the problem follows the injector then you will know whats up. If it does not, then you can divert your attention to the wiring / electronics.

Reminds me of a buddy's sled a few years ago... stock 05 900 would run great until it was hot, and then it would cut the pto cyl only when carving to the left. He sold the sled before we really got into trying to find the problem.:face-icon-small-con
 
B
Feb 21, 2011
28
8
3
Bend, OR
Danbot, great idea to switch the injectors, hadn't thought of that.
Garlic, the fuel pressure never drops, even when hot and the problem begins.
I'll switch the injectors next and see what happens. Time to pull the engine out again:( On a side note, I have to find an oil leak I developed after the last time I put it back together...
Guido, I'll definitely let you know if I determine an injector is to blame with Danbot's test idea.
 
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B
Feb 21, 2011
28
8
3
Bend, OR
After a long summer, we've finally got enough snow to ride. Over the summer I replaced the injectors with some off a good running 900 (thanks guidoxpress) and took it out for a test yesterday. I didn't have time to do a long ride, but it ran great! I want to get a full day on it before I'm convinced it's fixed, but it's promising. Thanks for all the help.
 
After a long summer, we've finally got enough snow to ride. Over the summer I replaced the injectors with some off a good running 900 (thanks guidoxpress) and took it out for a test yesterday. I didn't have time to do a long ride, but it ran great! I want to get a full day on it before I'm convinced it's fixed, but it's promising. Thanks for all the help.

Please confirm after your ride if it was the injectors ?
 
L
Jan 3, 2011
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langley b.c.
just a note i pulled my motor during the summer to replace motor mounts and general maintance and when i got it together and started it found mag side cylinder not running proved with a temp prob at each side of y-pipe pulled plug and found wet tested for spark and had spark checked further and found no fuel on cylinder caused by pins pulled back at injector harness they looked ok but werent making contact with female side of harness.. a couple things that can be deceiving 1 the plug was wet but with the oil injection it can be hard to distinquish a wet plug and an oily plug when one cylinder is running and 2 the way the rubber boot sits on the wire insulator it can hold the wires in place in the clip even though they are not fully seated... just something i found that i got lucky enough to find reasonably quick without spending a bunch of cash that i wanted to share in regards to this thread
 
B
Feb 21, 2011
28
8
3
Bend, OR
Last week we finally got some snow and I was able to put in a good day on the sled and I'm relieved to report that it ran very well the entire day! The injector must have been the culprit. On a side note, reverse is still not working...
 

guidoxpress

Well-known member
Lifetime Membership
Jul 13, 2008
5,105
1,506
113
Wasilla, AK from MT
Last week we finally got some snow and I was able to put in a good day on the sled and I'm relieved to report that it ran very well the entire day! The injector must have been the culprit. On a side note, reverse is still not working...

Glad I could help with the injectors bud..

As for the reverse..it's either a bad tps wiring harness, tps out of adjustment or bad tps..could also be too high of an idle ;)
 
B
Feb 21, 2011
28
8
3
Bend, OR
I put a new TPS harness on it and adjusted it while doing all the troubleshooting. That was last February though, and I've had the engine out of the sled since then, could have possibly bumped the sensor(?) out of adjustment...I'll have to recheck it.
 
D
Jan 5, 2015
1
0
1
just a note i pulled my motor during the summer to replace motor mounts and general maintance and when i got it together and started it found mag side cylinder not running proved with a temp prob at each side of y-pipe pulled plug and found wet tested for spark and had spark checked further and found no fuel on cylinder caused by pins pulled back at injector harness they looked ok but werent making contact with female side of harness.. a couple things that can be deceiving 1 the plug was wet but with the oil injection it can be hard to distinquish a wet plug and an oily plug when one cylinder is running and 2 the way the rubber boot sits on the wire insulator it can hold the wires in place in the clip even though they are not fully seated... just something i found that i got lucky enough to find reasonably quick without spending a bunch of cash that i wanted to share in regards to this thread
I wanted to add a response to this thread, as I was having the same exact symptoms as described above on my 05' 900. After laboring through most of the trial and error checks described in this thread, and after completely pulling the motor, sending my injectors in for cleaning and testing and finally deciding to replace the injectors completely (just to be sure). I put it all back together and still had the same issue. After hours of additional research on the web, I revisited this thread and this post jumped out at me. Sure enough, the pins in the mag side injector plug were not seated properly and were breaking connection after the engine warmed up. A very simple problem that cost a lot of time, money and patience. Gook luck!
 
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