LOW COMPRESSION 09 800 IQ - PLEASE ADVISE

[iride4fun]

I had a situation last weekend - updates all done on my 09 800 iq - bought it used, compression checked out good at purchase - 1000 miles ago. Last weekend about 30 miles into trip - mildly accelerating - approximately 5000 rpms it was liked someone hit the kill switch. Motor completely locked - pulled plugs- nice color brown. Put plugs back in and she fired right up. Ran it the rest of the day- night approx. 50 miles. The next day I burnt the chain and gears 50 miles later so my trip was done. Trip wasted - only 150 miles. Disappointed my whole family with this one.
After putting new gears and chain in yesterday I checked the compression. 105 psi in pto side - 85 psi in rt side - please advise as to what went wrong, what is wrong and a proper rebuild kit.
I checked the compression both cold and warm engine. not much difference either side, if any.
I have one trip planned to end the season - can I run it the way it is and tear it down later?
Please advise.
Thank you.
Mark

 

[Kraven]

I had a situation last weekend - updates all done on my 09 800 iq - bought it used, compression checked out good at purchase - 1000 miles ago. Last weekend about 30 miles into trip - mildly accelerating - approximately 5000 rpms it was liked someone hit the kill switch. Motor completely locked - pulled plugs- nice color brown. Put plugs back in and she fired right up. Ran it the rest of the day- night approx. 50 miles. The next day I burnt the chain and gears 50 miles later so my trip was done. Trip wasted - only 150 miles. Disappointed my whole family with this one.
After putting new gears and chain in yesterday I checked the compression. 105 psi in pto side - 85 psi in rt side - please advise as to what went wrong, what is wrong and a proper rebuild kit.
I checked the compression both cold and warm engine. not much difference either side, if any.
I have one trip planned to end the season - can I run it the way it is and tear it down later?
Please advise.
Thank you.
Mark

I'd recommend a MTNTK Piston kit beofre you go out with it again

Sounds like it was LEAN at part throttle, you'll need a fuel controller like a PC-5 and a corresponding map to richen it up

 

[iride4fun]

Kraven,
Thanks for the response.
Any links to the conditioner and how do I flash for it?

How about this kit on erape-- Sale Piston Cylinder Repair Fix Kit 08 09 Polaris 800 RMK Pro Assault Dragon | eBay. Is this a quality kit. Can I do this top end with the engine in the sled?
Let me know.
Thanks
Mark

 

[Kraven]

Kraven,
Thanks for the response.
Any links to the conditioner and how do I flash for it?

How about this kit on erape-- Sale Piston Cylinder Repair Fix Kit 08 09 Polaris 800 RMK Pro Assault Dragon | eBay. Is this a quality kit. Can I do this top end with the engine in the sled?
Let me know.
Thanks
Mark

Check with Jim at DYNOTECH, dynotechresearch, he sells the PC-5's and has maps that he'll include for free if you purchase from him

 

[iride4fun]

Update - more information - please advise

Okay gentlemen- more information - I have an update - please comment.
- It was suggested to me to retest the compression with wide open throttle- cold - so before I retested - I cleaned the exhaust valves and switched them to opposite cylinders. At wide open throttle with a cold engine I now have 100psi in the right side and 107 psi in the pto side. I feel much more comfortable with that - I am not sure my compression gauge is reading right- it could be reading low. Not sure how to calibrate the gauge.
I have been told that 105 psi is acceptable with no more than 10 lb difference.
I will still put the new top end on it - do I trust running it?

 

[Kraven]

Okay gentlemen- more information - I have an update - please comment.
- It was suggested to me to retest the compression with wide open throttle- cold - so before I retested - I cleaned the exhaust valves and switched them to opposite cylinders. At wide open throttle with a cold engine I now have 100psi in the right side and 107 psi in the pto side. I feel much more comfortable with that - I am not sure my compression gauge is reading right- it could be reading low. Not sure how to calibrate the gauge.
I have been told that 105 psi is acceptable with no more than 10 lb difference.
I will still put the new top end on it - do I trust running it?

Different gauges and different altitudes and temps read differently

At closer to sea level, 125 PSI +/- is in the ball park

Can you put that compression gauge on another sled for comparison ??

 

[iride4fun]

Updat - please comment or advise

Next update - I was able to get 135lbs compression at an idle.
I went out today and hooked up the compression gauge to each cylinder and ran it from cold at an idle on one cylinder - each cylinder quickly hit 135 lbs compression. Dead even on both sides running on 1 and testing the other -- is this a false reading. I decided to try the single cylinder idle test as I found that if I pulled it over really hard by hand - I could get the compression to go up on both sides. I did hook up my compression gauge to my air compressor to try and calibrate it. At 110psi by air - I was 3-5 lbs short on the compression gauge.
Just a little more info.
I did use this same gauge on my 07 600 - the motor was tired - both cylinders by this gauge were 105 lbs.
Thanks for any comments and help.

 

[retiredpop]

Couple of things. Is this the same compression gauge you used when you bought it? If so do you think the compression has dropped or are you at a different altitude now?
Also I would still be leery of the sudden stop you encountered. Possible lean seizure maybe. That's the way they act and it is possible to have a lean seizure even if the plugs look good. Can you pull the y pipe and take a look at the pistons to check for scoring or melting especially around the ring area?

 

[iride4fun]

It was not the gauge I used to test it when I bought it- I used the dealers of the place that I bought it. I will never deal with that guy again. I will share the story at another time. For all I know - his gauge was rigged.

 

[iride4fun]

Gentlemen,
Just put the top end in the last two days- waiting on a throttle body adaptor to fire it up. Thanks for all of your help.
What a mess.

 

[iride4fun]

Fix it kit installed with Weisco pistons. Tolerances much tighter - should be good to go.

 

[iride4fun]

First run on "the fix" - this weekend

Ran engine all weekend with the new update kit- 1st tank 50-1 oil added every other tank -no oil added.
Could only get 7800 rpms out of it- ran great thou. I have not done a compression test yet but I will later on in the week.
What rpms should I be turning?
It got real warm yesterday 48degrees and she didn't seem to run as good 7600 - 7700 rpms in the warm weather.