2008 Apex MTX (Need Advice)

[Doktor]

New to this forum and hoping I can get some insight to some problems I'm having. I have a Apex with a supercharger running about 10psi boost and my problems started with blowing the half moon plugs out of the valve cover gaskets. I siliconed them in and my dealer did a leak down test and said everthing is fine. Last weekend it started getting worse as the oil is now puking out my crankcase breather and it is starting to idle rough. The dealer now wants to pull the motor and do a complete tear down. The sled only has about 500miles on it and I hope this has nothing to do with the supercharger otherwise this is going to be a crazy bill.
Has anybody had this problem before or any ideas on what the problem could be?

Thanks

 

[lakercr]

New to this forum and hoping I can get some insight to some problems I'm having. I have a Apex with a supercharger running about 10psi boost and my problems started with blowing the half moon plugs out of the valve cover gaskets. I siliconed them in and my dealer did a leak down test and said everthing is fine. Last weekend it started getting worse as the oil is now puking out my crankcase breather and it is starting to idle rough. The dealer now wants to pull the motor and do a complete tear down. The sled only has about 500miles on it and I hope this has nothing to do with the supercharger otherwise this is going to be a crazy bill.
Has anybody had this problem before or any ideas on what the problem could be?

Thanks

Blowing that gasket out at 10lbs of boost is not a good sign. Your dealer leaked it down and said it was fine, but was is his definition of 'fine'?

Oil puking out the crankcase breather is worse. You can do a quick compression test to confirm, but you've more than likely taken down 1 or more cylinders.

What fuel were you running at 10lbs, and is this a stock engine, shimmed head?

Sorry guy, I know it's not what you want to hear.

 

[Doktor]

Stock engine no head shim 50/50 premium and 110 oct. Stage 1 Mpi supercharger.
The guy I ride with has the exact same setup with the same mileage and his is starting to do the same.

 

[lakercr]

Are you guys (hopefully) running wideband A/F gauges?

What are your readings?

 

[Doktor]

We have the Gems System on our sleds and have been making sure not to pin it until we get a few more miles on them. I'm a mechanically inclined person but far from a mechanic. We were told that this setup was basically bullet proof and little if any adjustment was needed from 3000+.
I appreciate any insight on how to prevent this in the future. Are we missing something that should be monitored? I have a 07 m1000 and this is the first yammi I have owned. I Will never go back to a 2 stroke again!!

 

[rxrider]

Does your sleds put smoke (or oil) out the crank case vent line? Most likely detonation have damaged the piston rings, pistons and the cylinders as well. If you tear them apart, make sure you measure your cylinders for out of round.

 

[Doktor]

Under normal riding they just vent hard but if you take a pull up a good hill it will puke oil out the breather.

 

[rxrider]

Oh no, compression gasses are blowing past the rings. Like lakercr said, do a compression test, it will tell right away if a cylinder or more are down. Again, rough idle sure doesn't look too promising. They usually do that when dotonation have done it's damage to the internals. Sorry about your loss, looks like the damage is already done :-(

 

[lakercr]

We have the Gems System on our sleds and have been making sure not to pin it until we get a few more miles on them. I'm a mechanically inclined person but far from a mechanic. We were told that this setup was basically bullet proof and little if any adjustment was needed from 3000+.
I appreciate any insight on how to prevent this in the future. Are we missing something that should be monitored? I have a 07 m1000 and this is the first yammi I have owned. I Will never go back to a 2 stroke again!!

Best way to prevent this in the future is to install a wideband A/F sensor and validate what it is telling you with plug readings. Start at around 14 for idle and the number should go lower to about 11.8ish for WOT.

 

[tko47]

had same problem 3 yrs ago on RX-1, you detonated it , the pistons are likely not round any more. I found out the hard way race gas is cheap if your running a stock engine. it needs to be taken apart, good luck....

 

[Doktor]

Thanks for the tips, I sure don't want to get bit for a second time! This bill is going to be nasty. So in the future should I run straight 110 octane fuel?

 

[yamiboost]

50/50 (110&91) is what i use @ 12psi. Sometimes i even run stright avgas.

 

[BlgsRX-1mtn]

Thanks for the tips, I sure don't want to get bit for a second time! This bill is going to be nasty. So in the future should I run straight 110 octane fuel?

I have a Stage 1 RX-1mtn and run 50/50 @ 10lbs boost. Riding in elevations from 3700' up to 11,000' with no problems after 3 seasons. I do run the wideband o2 sensor and WMS gauge that MPI sells.

Jim

 

[Doktor]

Looks like the equipment I need! Another question for you guys, I'm trying to track down a number for Iceage Maunfacturing for some rails, anybody running them with a big wheel kit? I have the timbersled rear suspension and these rails are supposed to be made to fit.

 

[stoutner]

Dok,

Mine was doing about the same thing as yours is. I broke a piston land when on nitrous. Get your hands on a compression tester and test each cylinder. You will find at least one cylinder is bad. It could be a valve problem but not likely. Did anyone have the cylinder head off? A bad valve could give you the same symptoms. Man, If I was running a turbo or S/C and had to tear it down, I'd probably install some lower comp pistons. Might as well since you'll have it all apart.

Anyone know what lower compression pistons and high performance connecting rods cost? I might tear mine down this summer and completely rebuild...make ready for a new turbo.