Just a continuation if anyone was curious. I've been keeping track of mine since I picked it up in early December. I had to back out of a trip so don't have as many miles as I'd like yet but it is what it is. I've never had a problem with this sled and it has ran great. At this point, I'm not worried, but I'd be lying if I said I wasn't just a little concerned with the leakdown tests creeping higher. Although they were done in a colder enviroment this last time around (not sure if that affects it much). Hoping to sneak out west one more time to put some more miles on the wknd of the 28th-31st if I can find somewhere with good snow/weather and I will check it again.At 20 miles 1.5%, at 340 3.5% and 132- 133 psi. I don't have papers in front of me and dont remember the hours off hand. Compression raised a cpl psi with more hours, I assume from rings getting broken in
Edit- both tests were done cold w 100 psi . I run polaris ves oil
I think Cat should start worrying about Polaris. With the new homoerotic colors of the Khaos all the lifer Cat guys are going to switch to Polaris :face-icon-small-disThe 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.
You are doing yourself a great service by testing your motor as you go.Just a continuation if anyone was curious. I've been keeping track of mine since I picked it up in early December. I had to back out of a trip so don't have as many miles as I'd like yet but it is what it is. I've never had a problem with this sled and it has ran great. At this point, I'm not worried, but I'd be lying if I said I wasn't just a little concerned with the leakdown tests creeping higher. Although they were done in a colder enviroment this last time around (not sure if that affects it much). Hoping to sneak out west one more time to put some more miles on the wknd of the 28th-31st if I can find somewhere with good snow/weather and I will check it again.
504 miles, 42 engine hours
4.25% - 4.5% leakdown both sides
132psi both sides
This last test, both were done when sled hadn't ran for a week in a semi-heated garage at 45* compared to 60* in my shop for the earlier tests.
got a link to the video?There is a massive difference between ( not mechanically inclined) and lazy.
A leak down test should be done if you are having any kind of performance problem....... Bogging, hasitating, not going into reverse, hard starting.not pulling rpm, poor idling & so on.
Bearing problems ?????????? If you have a bearing problem...... The results are almost always the same..... The motor will soon lock up.
If you do a leak down on 2 different sleds.....
Sled 1 - has 6%
Sled 2 - has 2%
Then you go ride both sleds...... You instantly understand the value of a leak down test.
The 2% will run substantially better in every way.
The 6% sled needs top-end work...... No need to trouble shoot it until the top-end is fixed.
This thread proves.....that the masses would rather wonder what's wrong and talk endlessly about small problems then do a leak down test.
We did put in a large order of leak down testers that should be in soon and we are also going to do a YouTube video showing how it's done if anyone is wants to
See the procedure performed.
If it’s a cylinder finish problem you see the damage firstI'm guessing it is more important in this case as the other parts of the piston look fine, it is just in one location. If the finish was to blame I would expect to see damage, more even over the piston.
So some people have put their sleds away for the season and some are still lucky enough to still ride. If your still concerned over this and need help (Ive walked a couple people through this over the phone). Your welcome to stop by my shop if your in Upper MI. Ive also done a couple in my enclosed trailer out west. I keep a separate tester in there if you see me out or stop by if your in the Yoop (Send me a PM 1st). I'm guessing "most" sleds are fine but some are still nervous over this. If your numbers are low, the off season would be a good time to get it to the dealership.I repeated the leak down test on my 850 with a different test kit and ended up with the same results as my more expensive tester. The cheaper one is an OTC 5609 on line.
My tests using 100psi at TDC was 98 which = 2% leak down. I only use Polaris Extreme oil. Test done at room temp and motor cooled to touch after running. If you haven't done one before I would use something soft (like a Q-tip) to find TDC top dead center after pulling your spark plugs. Of course do 1 cylinder at a time, but you will need something or someone to hold the primary clutch from spinning once you add air pressure. Do not damage your clutch!! A clutch tool from SLP works great or you could be careful and use a wooden broom handle. Once I find TDC I put a sharpie mark on the end of the clutch bolt so I know it hasn't rotated under pressure.
1st pic is gauge hooked up before air pressure added.
2nd pic is with 100psi shown on left gauge, right gauge is how much the cylinder is holding.
3rd is Operating instructions. At the bottom you will see that my cylinder at 100psi held 98psi which translates to 2 percentage of leakage.
4th Cheap kit that can be ordered on line for cheap at less than 1/5th of my "good brand" that showed the same results.
5th OTC cheap compression tester. Didn't read as high as my higher $ tester, but it was consistent on several cylinders I tested. When I test compression with any tester, I only compare prior readings from the same tester for this reason. What is more important to me it the pressure differential between cylinders. For example if one is 130psi, and the next one is 115psi you have a problem.
6th is the cheap compression test kit part # 5606
7th is my reference above about marking the clutch bolt once you've found TDC.
Hope this helps.
What do you mean by this ?All these posts and 3 or 4 people have posted leak down numbers. Seems all these threads are about IndyDan now.
Quote:What do you mean by this ?
Leak down tests are the only way to check the the true condition of the top end.
it’s surprising how many people will not do it.
performance problems cannot be trouble shot accurately without leak down numbers.
Great question....... I can't give a 100% positive answer to that.Wouldn't a single ring leak down faster than a double ring at the end gap, unless the single ring end gap overlaps? What is the std. end gap on a 3.34" bore? Seems like it would just leak real fast unless oil was taking up the space.
He just states the facts...a lot of people simply have permanently ruffled feathers from a chronic case of knowitallness.For me this had nothing to do with Indy Dan. Yes, he has some valuable insite and recommendations. And yes he is good at ruffling peoples feathers lol.