apex mountain low compression... help please

[StrRacerX]

hey guys, new to this site and definitley new to the rx10ml. i have a 06 apex mountain engine with a mpi supercharger swapped in a polaris rzr. I was tuning it and the starter took a crap. i replaced the starter and added a thicker head gasket for lower compression (0.051 thick). my compression is 80 in all 4 cylinders... i torqued down the head in stages and loosen 1/4 and back to final torque number... i dont remember what the numbers were but i did get it from this website

any suggestions, or anything i can check out?

also i am in san diego ca, not too many snowmobile experts here, anyone have suggestions for a good tech in southern california?

thanks

 

[StrRacerX]

Anyone out there?

 

[Viper_Dave]

I'm moving your post to the Turbo/Supercharger section. Look at RxRider's thread about building turbo motors. There will definitely be more help in that section. Good luck!

 

[kinger]

What do you need help with?

 

[TurboM700]

If it happened right after doing the head shim I'm guessing your cam timing is wrong.

I would go back thru and double check that.

 

[StrRacerX]

I went back to recheck my timing. according to the service manual, I have to line up the line on the magneto with a stationary line on the case. there are 3 lines on the magneato as you're turning it clockwise, two close together and 1 a little bit further down. which 1 is the TDC line? The sm dosent say.

Thanks

 

[Some_Boost]

i would do a leak down test you might have bent a valve . if the timing was done wrong.

 

[StrRacerX]

i would do a leak down test you might have bent a valve . if the timing was done wrong.

Are these motor a interference motor?

What about the multiple lines on the magneto? Sm doesnt say which line is 0°.

 

[Some_Boost]

yes they are interferance motors , you want the pto and mag pistons at TDC and then put your cams on and have lines on the cams level with the head. the SM says line the "I" mark up with the line on the cover , dont worry about the other lines just the single line thats all

 

[Some_Boost]

oh and update your info , we need you location please, maybe if theres some one close to you they could come over and give you a hand .

 

[StrRacerX]

Im im san diego california. Is there any apex mechanics in southern cali?

Also, if I had a bent valve, wouldnt only one or two cylinders be low compression? I have 80 on all 4 cylinders.

 

[spddmon]

what was done to the eng before it was installed in the rzr?

 

[StrRacerX]

Just a mpi supercharger. Original owner said it had a shim on the head to lower compression... There was not one.

Starter bearing went out well tuning, sounded bad, I thought a piston was cracked. Did a compression check, 65 on all cylinders. Pulled the head. Found a bad starter. Installed new thicker head gasket. Now compression is 80 on all cylinders. I think I effed up the timing. Im pulling the head right now to verify valves arent bent.

I torqued the head from a middle to out pattern to 14lbs, then 25lbs, then tge final torque... I forgot, but I found it here on the forum.

Thanks again