[Njn1995]

I have a 2017 uforce 800 while in park neutral and reverse the unit runs operates smooth rpms will climb to around 5000 with no issues what so ever. In high gear when accelerating the rpm will only go around 3200 and mph sits around 25. The side by side will barely make it up a hill in high gear. My seat belt was on and the diff lock was off. The issue started a couple days ago while in wide open throttle it would sputter and go down to 3200 rpm and sit around 25 mph. Now it does it constantly in high gear. I cleaned out the air filter, replaced with new fuel, and checked all sensor connections still having issues.

Thank you for the help

[NMKawierider]

I have a 2017 uforce 800 while in park neutral and reverse the unit runs operates smooth rpms will climb to around 5000 with no issues what so ever. In high gear when accelerating the rpm will only go around 3200 and mph sits around 25. The side by side will barely make it up a hill in high gear. My seat belt was on and the diff lock was off. The issue started a couple days ago while in wide open throttle it would sputter and go down to 3200 rpm and sit around 25 mph. Now it does it constantly in high gear. I cleaned out the air filter, replaced with new fuel, and checked all sensor connections still having issues.

Thank you for the help

Sounds just like the problem another member was having. For some reason the reverse RPM limiter was no longer triggered in reverse but was in the forward gear positions..ie the skyblue/white wire on the ECU found a ground. I suspected the gear selector switch or a problem on the board in the pod but the member elected to snip the trigger wire on the ECU and it started operating normal. This didn't fix the problem...just the symptom. I have a How To video in the How to section on doing this on a ZForce which would mostly apply to the UForces except the ECU location might be different. I do urge you to actually find and fix the actual problem though.

[Weatherly Repair]

Sorry, this has nothing to do with the last post, but I'm new to this site & didn't know how to post a question. Here it is; Customer brought his 2016 UForce 500 EFI into my shop because of a no start. The engine has 125 psi compression, but acts like the ignition timing is WAY advanced. The starter will barely turn the engine over on the compression stroke w/the spark plug in. With the compression tester, the engine spins no problem. My customer had it at another shop, which he said the shop advanced the timing due to low power.
  Can a guy manually set the ignition timing on this electronic system?
   Is there a service manual available?
  Any help woud be much appreciated.

[NMKawierider]

Sorry, this has nothing to do with the last post, but I'm new to this site & didn't know how to post a question. Here it is; Customer brought his 2016 UForce 500 EFI into my shop because of a no start. The engine has 125 psi compression, but acts like the ignition timing is WAY advanced. The starter will barely turn the engine over on the compression stroke w/the spark plug in. With the compression tester, the engine spins no problem. My customer had it at another shop, which he said the shop advanced the timing due to low power.
  Can a guy manually set the ignition timing on this electronic system?
   Is there a service manual available?
  Any help woud be much appreciated.

You can not change the spark timing except in two ways, one, reflash the ECU with a different set of maps or install a degree key changing the pickup point of the CPS. Both are unlikely at an average shop. But do inspect and test the engine speed sensor...aka CPS. What is more likely here is that the valve timing has jumped a tooth...and that happens when an old CFM issue comes into play. That is failure of the chain and/or tensioner.  I may have a U500 manual and if I do, I'll PM you with a link. If I don't, you won't get a PM from me.

[NMKawierider]

I had one and you got a PM.

[doug80638]

125psi is a little low but seems reasonable given the age, and it was tested cold.

It makes no sense that it would turn over differently with a compression gauge or a spark plug. Makes me think the gauge is leaking, which might also explain the low reading (should be closer to 145 psi).

Definitely check the timing marks and chain for factory alignment and tightness if another garage says it "advanced" it  the timing.

You might also want to load test the battery, as these machines don't like low voltage during startup.

After that, the diagnostics process begins. (fuses, kill switch, fuel pressure, etc ...)

[Weatherly Repair]

I got the PM with the manual. Thank you for the help! I tested the CPS & found the resistance in the 900's! I'll see how the machine acts after I get the new sensor.

Thanks again for the help.