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Discussion Starter · #1 ·
Dealer replaced PTO Cylinder and put in a new set of rings after they ruined the cylinder trying to get a broken exhaust stud out. I put about 100 miles on the sled and checked compression. 135 Mag side/124 PTO side We're leaving for Togwotee tomorrow for a week. Is it going to make it?
 

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Summit motor has high comp head on it...should be around 155-160 I believe.

That sounds low even for a std 800. What did the dealer do..put in some old rings that were pitted or what? The new chrome rings should seat rather fast....either that or you need a new compression tester.
 

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ITs WINTER!
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It is quite a ways over the reccomended variance but both are still fairly high (easily enough to run) and shouldnt be a problem. Your going to want to look into it first thing when you get back, could just be junk rings the dealer put in there.
 
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Discussion Starter · #4 ·
Thanks guys-----I'm not 100% sold on the talent of the mechanics at my dealership, but I'm pretty confident that they put "new" rings in. I'm not as concerned about how high the readings are (accuracy of the guage), but more the fact that they are off by over 10 lbs already.
 

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Aux670 said:
I left a reply on the Mountain Sled thread as well, but my '04 with new rings 200 miles ago has 165 PTO, 170 MAG.
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Your still within spec, your good to 160/170 since your overall compression is nice and high.
 

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If his tester is somewhat accurate he is out of spec, with one jug at 135 the lowest the other jug should be is 128.

Now if he puts it on another tester and comes up with very similar numbers hes got a problem on his hands. But if it comes up something like your 170/165 hes obviously good to go.
 

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That said:
Dealer replaced PTO Cylinder and put in a new set of rings after they ruined the cylinder trying to get a broken exhaust stud out. I put about 100 miles on the sled and checked compression. 135 Mag side/124 PTO side We're leaving for Togwotee tomorrow for a week. Is it going to make it?
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Was the engine HOT when you did that test ? That always gives inconsistant and LOWER readings.

Do your comp checks on a room temp engine on run just for a few seconds first and always do it the same every time (throttle wide open too).

Sometimes rings take severall hundred miles to fully seat and compression to come up, my last ring job it took well over 300 miles before I saw 150 PSI with a 5 hole base gasket.
 

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i also had low/inconsistent compression on a 600HO after 100miles. like 11c said, give it some time -mine took over 200mi to get over 150psi. hope it works out
 
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Discussion Starter · #12 ·
Ok guys, just an update. About 600 miles on new cylinder/rings. Cold mag 115 / pto 115. Engine hot, mag 100/pto 125. Thought my gauge was on the fritz, so I borrowed a buddy's----same results. Test at less then 1,000 feet at WOT. Dealer says "as long as its running, finish out the season" Give me a break!! Am I going to do further damage my running it? I kinda wish it would just throw a rod and be done with it! Any suggestions? Thanks
 

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My 05 PT 800 is at 150/150. Like said do the leakdown, I bet it fails. e had a motor with good comp and the leakdown was 80%..the rings were bad. Put a cup of water in each side, this will up the comp big time
Just kidding, sorry for the problem, your dealer is a tool. You could do this yourself in hours so it is not too late.
 

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You can buy the gage for about $50, you need shop air and you can convert your comp gage to one with a fitting between the gage and the connecting end, it just needs the adapter for air and a shut off valve when used as a comp tester. That comp sounds too low, it may not be the ring but a gouge in the wall, I would pull the head and see, it is the easiest quickest way.
 

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That said:
Ok guys, just an update. About 600 miles on new cylinder/rings. Cold mag 115 / pto 115. Engine hot, mag 100/pto 125. Thought my gauge was on the fritz, so I borrowed a buddy's----same results. Test at less then 1,000 feet at WOT. Dealer says "as long as its running, finish out the season" Give me a break!! Am I going to do further damage my running it? I kinda wish it would just throw a rod and be done with it! Any suggestions? Thanks
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I'd say there's a problem unless they put in a big 8 hole base gasket (that should not be in there) either way that dealer doesn't sound too helpfull.
The compression should have went up in 600 miles not down so even my thick gasket theory may not make sense
 
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