[rpfeiff]

I have an 08 with 6500 miles. Lately, long runs at high speed I start to lose power. It will do 55mph for a short burst then slow down to less than 40mph. No back fire, no hesitation, just won't go any faster until I back off the throttle for a while and try again. I replaced the fuel pump and still won't keep going at high speeds. Work perfectly otherwise. Any ideas?

 

[Pirate]

Probably time for a top end job.

Do a compression check and a cylinder leak down test.

Remove the air cleaner filter have someone hold the gas pedal down and look through the air inlet duct. Is there dust in the duct before the throttle body? Is there "mud" behind the throttle plate and into the intake manifold?

Those are some easy diagnostic tests that will tell you a lot about your motor.

Also, did this just start to happen or has it been slowly getting worse?

Pirate

 

[rpfeiff]

Thanks Pirate. Slowly getting worse.I'll look at th things you suggested.

 

[Pirate]

If you continue riding, be sure to check the oil often and make sure you carry a couple of quarts with you. If things get worse, it happens in a hurry and the oil disappears...and ruins the whole motor.

Been there done that, and those with us never saw smoke from the exhaust...but the motor burned every bit of it and then completely failed!!

Pirate

 

[rpfeiff]

If you continue riding, be sure to check the oil often and make sure you carry a couple of quarts with you. If things get worse, it happens in a hurry and the oil disappears...and ruins the whole motor.

Been there done that, and those with us never saw smoke from the exhaust...but the motor burned every bit of it and then completely failed!!

Pirate

You were right. Top end is done. Now to rebuild. Not wanting to do anything crazy but I wouldn't mind doing a little more than just stock. Don't need tons of power, just reliability.

 

[desertvet1990]

I have an 08 with 6500 miles. Lately, long runs at high speed I start to lose power. It will do 55mph for a short burst then slow down to less than 40mph. No back fire, no hesitation, just won't go any faster until I back off the throttle for a while and try again. I replaced the fuel pump and still won't keep going at high speeds. Work perfectly otherwise. Any ideas?

I started having the same kind of problem. Went to change the brakes(not related) and noticed my Wheel bearings on my '08 were toast. Almost siezed up and dry as a bone. Even had a set fall apart in my hands. Replaced them and got alot back. Its amazing how much they will hold you back.
Wouldnt hurt to try this. For $200 from American Star, Im happy!!

 

[Pirate]

rpfeiff,

I'd look at the Trinity big bore kit. The Holz Stage III is awesome, but to get your money's worth...it takes the whole kit, which includes Cam, lifters, pushrods, head, cylinders, pistons, ECU and Muzzys dual exhaust...so a lot.

I believe Trinity and others can provide you with a "big bore" kit, just the cylinders, pistons, and needed gaskets and rings.

Takes a lot of thinkin to figure out what to do to match your plans and budget.

Just some thoughts,

Pirate

 

[JBergstrom777]

Mine doing the exact same thing today. Under full throttle for a minute or so & it starts stumbling, breaking up & losing power. Mine sounds like the valve train & everything getting louder. Turn the key off & let sit for a minute or stay out of the throttle for a little while & its good to go. Mine is an 08 & only right at 1000 miles. Last oil change about 75 miles ago.

Just checked my oil & not even on the dip stick! Can honestly say thats a first for anything I have ever owned. Wow....Think thats all it was & it should be okay with a fresh oil change or did it hurt it?

 

[whaffner]

JB, your oil went somewhere. You need to figure out where the oil is going. It's either leaking it out, or burning it up. Compression check.

 

[JBergstrom777]

Gonna dig into it tomorrow & see what I find. Just as a general rule of thumb how often would you typically have to add oil to these engines? I think I read somewhere on here that its normal to have to add oil because they burn a little. Is that correct? I bet I rode it 10 times after I changed the oil & never even checked it like an idoit & it was 275 miles not 75. Just realized my typo in last post.

 

[whaffner]

shouldn't use any, if rings are good

 

[Hayseed]

1400 miles on my '11 and it has never used any oil between changes.

 

[Orangemadness12]

Over 3500km since my last oil change and hasn't burned a drop. Stupid question but have you checked for any oil leaks?

 

[JBergstrom777]

I store it & work on it in my garage & has never been any oil under it. I will dig into it tonight & see what I find. Hopefully I didnt bust something on my ride yesterday & find it empty or something.

 

[Pirate]

Sadly, I'll bet you find the compression to be low and that's where the oil is going.

I'm not sure on oil consumption. RZRs are water cooled. Harleys are air cooled. All six of my Harleys had varying oil consumption. Some rides, didn't use a drop. Some rides, use a quart in a 300 mile day. Figured it was a function of cylinder temp and expansion.

I change the oil in my RZR after every major ride or rally, so probably about every 350 miles. Have had to add as much as 6 ounces at the end of a day, other days not a drop. But I check it every day. Fire up the motor, let it run about 20 seconds, shut down, check oil...add as necessary.

JMO

Pirate

 

[JiAnthony315]

Mine doing the exact same thing today. Under full throttle for a minute or so & it starts stumbling, breaking up & losing power. Mine sounds like the valve train & everything getting louder. Turn the key off & let sit for a minute or stay out of the throttle for a little while & its good to go. Mine is an 08 & only right at 1000 miles. Last oil change about 75 miles ago.

Just checked my oil & not even on the dip stick! Can honestly say thats a first for anything I have ever owned. Wow....Think thats all it was & it should be okay with a fresh oil change or did it hurt it?

You should check your fuel pump...Mine did the same thing and my fuel pump was bad..Changed it and runs fine..My oil level was fine though

 

[JBergstrom777]

I changed the oil/filter & when I drained it I bet there wasnt more than a quart or so of the old oil. Couldnt find anywhere oil had leaked so I am going to check it after I ride on Sunday & see how it looks. Rode it around through my neigborhood & tried to get it warmed up good. Was working perfect & then started missing all over the place & barely made it back in the driveway. Hooked up the laptop & was looking at the power commander & it wasnt trying to add any fuel like it was lean. Checked for codes, none. took cover off behind seat & saw the spark plug wire was not snapped down good. Popped it back on & drove it around for 10 minutes or so & ran perfect. Hope that was it all along! Lucky if thats all it was.

Does that ever happen very often? Dont know how that could have happened. Im sure I put dielectric grease & snapped them on firmly when i changed the plugs at the beginning of last summer.

 

[Pirate]

My experience has been that getting the spark plug boots off is the hardest task on a RZR!!!

I would go ahead and do a compression test. One thing my experience has showed me is that the motor can burn all the oil in it, without ever seeing any white or blue smoke...all the way up until the motor completely failed.

I check the oil after every ride and find there are times I have to add a couple of ounces. Not a lot, but its using a bit. The only engine I do not regularly check is in my diesel pick-up. I suspect that is because the compression in a diesel is so high, the piston ring fit has to be nearly perfect, thus no leak by.

JMO

Pirate