2012 Proclimb Misfire at 6000+ RPM

[firecat1250]

Hey guys trying to narrow down an issue with my 2012 Proclimb. While riding last week I started to get a misfire at 6000 RPM. Thought it was plugs so I replaced those......no change. Unfortunately, it's not throwing a code. Yesterday I tore into trying to find the issue. This is what I've already done or checked.

-Drive clutch full rebuild
-Driven clutch full rebuild
-TPS delete with tether
-New plugs
-Air sensor relocate
-Injectors - Tested and Cleaned
-V-Force 3 reeds - Checked (look like new)
-Servo motor - works as it should
-Power valves - Cleaned and work as they should
-Great compression - Pistons and cylinder walls look great
-Checked all connectors under the hood

The sled is acting like I'm hitting a Rev limiter at 6000+ RPM. How does the quad plug setup work? From what I can see on the Cat Service Manual, there are primary and secondary coils. Do these fire at different times in the RPM range? How would I go about testing the coils? Also wonder about the stator.

The sled is very snappy and runs great up until the 6000 RPM mark. Any help on what direction to go would be great.

 

[firecat1250]

Checked all 4 coils and the stator. All seemed to be within spec except the lighting coil. That seemed a bit high but I'm not having any lighting issues. The misfire seems to be a bit higher RPM than I first though. More like 7200-8000 RPM. It seems to be better if I slowly increase throttle vs right to WOT.

 

[boondocker97]

Had an issue last year where my fuel pressure was getting low and was running a little lean when I'd run it at WOT. My stator was the issue but a bad pump might cause problems too. See if you can get a fuel pressure gauge on it and see what it's doing to rule that out.

 

[firecat1250]

Sounds good. I'll tear into the fuel system tomorrow. Thank you for the reply.

 

[Readymedic]

Sounds more like a clutching issues. Are you sure about your RPM., sounds like your not really sure. Although you cleaned your valves, is the motor working to control your power valves. My 14 did not like the air temp relocate, it wouldnt even run close to properly.

 

[firecat1250]

Both clutches are fully rebuild. Both seem to be working perfectly. I put the sled up on a track stand and run it without the belt guard to verify this. This is more of a misfire in the engine than a bog. I have both Proclimb and Procross driven clutches that I've tried and the problem persists no matter what clutch is on it.

Yes.. I powered the servo motor separately to verify that it works. I pulled the hood off the machine and verified that it's opening the valves while hooked up and running.

What I don't get is why it's not throwing a code during a lean condition in addition to the misfire which I would think would throw code.

 

[spoon]

Lean condition wont throw a code unless you have bad enough detonation. Running out of fuel at high RPM load sometimes cuts power enough to notice but not hurt engine just not make power. Tee a fuel pressure guage in and see if you can duplicate condition and watch fuel pressure. Easier said than done I know. I have a turbo kit I just installed and having similar issue and need to do more testing to see if pump not putting out enough or if secondary injectors aren't coming on.

 

[firecat1250]

Fuel pressure stays right at 43 PSI throughout the RPM range. I pulled the fuel pump and smart valves out to make sure everything was good. The front smart valve did look to be fully closed. I pushed on it a few times to release the fuel. Not sure if this is normal or not? The pressure readings I took was after pulling the smart valves out of the tank to inspect. Not sure if that was the problem or not?

 

[firecat1250]

Just finished checking the full fuel system again including smart valves and fuel pump. Vented smart valve is first in line now. Topped off with fresh premium after checking every other component of this sled. Still have the top end misfire and not sure what to look for anymore.

I've always been a cat guy but this sled has completely ruined that. I'm at a loss with this thing. It's been problem after problem. Might be time for a full part out.

 

[firecat1250]

Replaced the BMP Powder Lite can with the stock exhaust. No change. Pretty much at the end of the road for things to check.

 

[Old & slow]

Checked all 4 coils and the stator. All seemed to be within spec except the lighting coil. That seemed a bit high but I'm not having any lighting issues. The misfire seems to be a bit higher RPM than I first though. More like 7200-8000 RPM. It seems to be better if I slowly increase throttle vs right to WOT.

The lighting coil does power your servo motor for the exhaust valves. If the servo motor isn't seeing proper voltage it may not be opening the valves. Country Cat has service manuals. Good luck

 

[firecat1250]

Servo tested and good.

Been doing some testing with different helix's. Was running a 44/40 and dropped back to the 36. Thinking the combination of the C3 belt drive and the 44/40 helix, it was seeing an over rev case?

 

[firecat1250]

Well.......my issues continue. Took the sled for a 30+ mile ride and ran great in the beginning. The longer I rode the more I noticed the misfire was back. From what I can see, the misfire I'm seeing is a lean condition due to lack of fuel. Went to leave camp, fired the sled and it died right away. Then no fire after that. Trailered it home to find no spark. Fuel pump worked great when hooked to a battery.

What I suspect is I've been dealing with a voltage issue from the start of my problems............bad stator or voltage regulator. I did notice my hand warmers were much warmer than I remember.

Will a bad voltage regulator cause no spark?

 

[firecat1250]

Just wanted to report back that the issues have been fixed. Boondocker97 gets the prize. Was a fried coil on the stator.