07 Rev Goes down...what's the fix?

[shawnmcgr]

I've read all the '07 Rev threads I can find here. There aren't any before '10 so maybe the good ones on this issue got nixed?

Anyways, a buddies '07 Rev Summit was backfiring and hard to start (1700kms on it). He left fuel in the carbs over the summer and just started every month and thought maybe the carbs needed cleaning.

Dealer gets back to him and 50psi compression on one side and they say marks on the cylinder. 120psi on the other side. They are going to tear it apart but they are saying likely new cylinder and piston.

I've heard these '07s had some motor issues, poor crank bearing lube if I've heard right. One of the crank bearings needs to be greased as it doesn't get enough injector oil lubrication, is that right? Was thier piston issues as well?

So what's the right fix here...is this just bad l luck? Should both pistons be changed out to something better? Is there something that should be done to the crank while it's @ the dealer? Greased? He just wants to make sure whatever needs to be addressed is done while it at the dealer, he not a wrencher. Doesn't want to worry about the other side burning up.

If these '07 are a "ticking time bomb" did BRP ever cover any work with extended or secret warranties?

Thanks,

Shawn

 

[summit1974]

i think its just bad luck...i have 2000miles on mine and its fine

 

[Slamnek]

The bearing tolerances on the crank bearings were too tight on lots of 07's. With 1700km's on it i would guess that the crank is good. Get a crank run out done at the dealer and if its with in spec then put a good set of pistons in it and ride away.

 

[imdoo'n]

while the motor is apart, it makes no sense in not pulling the pto side seal and check grease and or add. at this point cost is low. if the rear of the primary clutch is greasy in any way, pull the seal as it is leaking, don't even ride until it's done. i just finished pulling the motor in my 08, pto side gone, bearings, rod, piston, cylinder, head. $2300 for short block + labour+. shheeet for the $150 have the seal taken out, regreased and new seal installed.
i did get 4500 miles on motor.


friggin wrenching in the cold.

 

[maxwell]

7200km...ya that motor did well

 

[imdoo'n]

yeah, it grenaded, on the primary clutch side. heard some strange grinding, thought it was clutch, everything looked ok and sounded good at idle but went blahh not much farther. was kind of expensive. did find a low km motor, got my fingers crossed.

 

[shawnmcgr]

Turns out it's more than a cylinder and piston, cranks gone too. One of the middle bearing on the crank is nfg. I have not seen the damage but sounds like mucho $$. Doesn't sound like the case is damaged but theory is a piece of the bearing went out of the crank and up into the piston and bounced around up there - there's damage to the pistin top. No theories on why the bearing went

Might be short block time. Hard to swallow at 1700kms!

 

[maxwell]

sounds about right. i agree 1700km is to early

but these motors are notorious for this issue. 2000$ and a night in the garage you guys can get it runing and it will last for a long time.

 

[jackinthebox]

Mine went just last week @ 3300 miles/5300 km ,center bearing on crank went for a shyte.Took some material up the mag side piston scored cylinder pretty good.It didn't strand me,i put another hard 60 miles on it the day it started acting up.
Knew something was up,was ripping down loggin road and it died like somebody hit the kill siwtch or flooded it.....Fired it up and rode hard the rest of day...BUT would not idle correctly or go into reverse..
I got it home and started tearing into to find the mag side piston badly scored.....compression test showed 50 psi mag 140 psi pto ...tore into it more and found bad center crank bearing
Noiw looking @ short block options.

 

[MoFoREVxp154]

The best option is a updated short block 421000645
Just make sure there are not pits in the head or you will be doing it all over again fron detonation due to a hot spot in the chamber.

 

[jackinthebox]

I've got REALLY SMALL pits,BUT was told they can be smoothed out with emery cloth.No big ones like i have seen.just small.