E
So about 6 weeks to get it back and with pulled threads in the case. not bad
LeakDown results- post em up
- Thread starter minus40
- Start date
D
Discovery motor sports Yorkton sask. Tech that knows and cares what he is doing and wants to actually help you out.
125psi compression and 4% leak on mine with OTC tester at 320 miles.
Thumbs up !
So nice to see people going thru the work to check their leak down %
Leak down numbers don’t lie.
If you have leak down numbers in the 1 to 3%..... your top end will make really good power if all other areas are functioning correctly.
4 & 5% are still ok.... past 5% starts to get a little grey.
If it stays at 5% for a several hundred miles not horrible.... but you won’t have the fastest sled on the block.
6,7,8,9,10 % in my opinion it needs to come apart soon.
Dan
So nice to see people going thru the work to check their leak down %
Leak down numbers don’t lie.
If you have leak down numbers in the 1 to 3%..... your top end will make really good power if all other areas are functioning correctly.
4 & 5% are still ok.... past 5% starts to get a little grey.
If it stays at 5% for a several hundred miles not horrible.... but you won’t have the fastest sled on the block.
6,7,8,9,10 % in my opinion it needs to come apart soon.
Dan
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What temperature is the engine at when you test yours Dan? I did mine at room temp "65F" and did not run it prior to testing. Maybe I should have done it with a warm engine instead?
leak down
my leakdown tested just under 2% at 612 miles. Has ran great from the start. Reflash cleared up slight richness at low rpms. These are all mountain miles
my leakdown tested just under 2% at 612 miles. Has ran great from the start. Reflash cleared up slight richness at low rpms. These are all mountain miles
70 degrees sat overnight
Not warmed up
To give people so,etching to hang their hat on........ ( an example )
A 2002 500 XC EDGE was dropped off because it doesn't run right.
Customer said it starts good and idles pretty good...... But it it seems really rich and has not top end speed.
One of the shop guys drove it and said it seems like it needs to be jetted down a few sizes on both pilots and mains.
I said check if it has stack jetting....... It was already down one size from stock..
I said do a leak down check
45% on the PTO and 3% on the MAG.
Np tuning in the world will fix this problem..... Yes it will run better jetted down on one cylinder.
But it's down 45% power on one cylinder.
Leak down is the best trouble shooting you can do.
Dan
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So just out of curiosity, in your opinion do you think if he had done a standard compression test he would have noticed a difference as well?
Theres a good chance not. One of my trail sleds (04 pro x2) i seized tight let it cool at a gas station broke it loose by grabbing the primary at the gas station fired it up and drove it 50 miles home. Ran completely fine. Before tearing it down i did a compression test, 125 psi both sides... Tore it down, cylinder was all tore up and the piston had a standard 4 corner seizure.
S
What evee happend to chadlys comments on here i thought they were pretty good.... mods delete them?
sure looks like it
Compression check does not work very good.
To much much piston speed...
People holding the throttle open....doingg everything to get it higher.
To many pulls.
Leak down is the only way to see the truth.
Major damage can be found with compression check.... but it’s still lame.
Dan
Definitely the BIGGEST troll on this site - by far!! No self-control at all. Nothing he says has any value at all, and adds NOTHING worthwhile or constructive to the conversation!
Surely there is someone who might enjoy his "contributions" on another part of this forum (cat section) . . .or on another site altogether, would be best case scenario.
I have found that the "ignore" feature works VERY well to keep that little "bugger" away
please please please share with the class how I go about putting this troll on ignore
I have the OTC tester and have never got good numbers. 1 ride on a brand new top end and I'm getting 4% & 5%. Compression test is 128psi both cylinders though.
Prior to the first rebuild I was seeing 7% & 8%. It was running 250-300 RPM shy of my buddies 850. Oil line popped off and it was tore down. Here were the pistons:
What do people think happened to these pistons ? ........, what causes that kind of damage to pistons and rings ? I would really like to hear opinions.
I wonder if a head with a ( State Name ) would have helped this problem ? I wonder if milling machine grooves in the combustion chamber would cure the piston problem ?
7 to 8% leak down found this......... those pistons and rings are junk.
Compression would have most likely showed nothing wrong.
Dan
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What do people think happened to these pistons ? ........, what causes that kind of damage to pistons and rings ? I would really like to hear opinions.
If you turn the volume up, you can hear how the competition reacts to the 850 Patriot's first year out.
https://youtu.be/0SNqvFN4RnU
If you turn the volume up, you can hear how the competition reacts to the 850 Patriot's first year out.
https://youtu.be/0SNqvFN4RnU
The 850 better start worrying about the Cat...... the Alpha is one badazz machine.
Polaris will not get good consistant performance feedback until they get their cylinder finish problem fixed.
Inconsistant cylinder finish means inconsistant piston life.....which sad to say leads to sleds that run complete different within the same exact model.
Dan
<div>I do agree, but cat is having their share of inconsistent running as well.</div><div>Figuring out all this inconsistency will benefit us consumers greatly!</div>
N
Is your opinion the cylinder finish?
Could it be a chamfer issue on exhaust port as well chewing things up?
Cylinder finish in silicon carbide cylinders is the number 1 cause of inconsistant piston life.
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