LeakDown results- post em up
- Thread starter minus40
- Start date
In case you haven't heard there seems to be a push on leak down testing.
850, 24 hours run time, 5.5% both cylinders. Using extreme oil. OTC gauge.
Ouch! For your sake I hope Dan was just throwing numbers out...
He had 3.5% for new, 1.5% for broken in and running strong, 7% junk...
5.5% at 3-400 miles by the numbers given, doesn't bode well. Maybe Dan can clarify.
hot? cold? with oil? dry? it depends a lot, we shoot for 5% or less in a top level race engine, (at running temp) when it gets over 8-10% time to re ring and hone again. Just as a reference in alloy blocks i've seen them leak at 15%+ cold and 2% hot.....4 stroke, 4.700 bore deals
I would like to know what Dan, SLP, Wahl bros,cutler, etc like for a 2 stroke sled motor??
I would like to know what Dan, SLP, Wahl bros,cutler, etc like for a 2 stroke sled motor??
I can tell already this thread is going to be all over the place one guy saying apples the next saying oranges... multiple leak down testers of questionable quality and accuricy... pretty soon it will come down to the build date who got a good engine lol
A leak down test is used to diagnose problems with your engine. There is more things that can happen in 4 strokes that I would normally test for like leaking valves. This is just a basic description of how it works. I would go by the recommendation instructions on your tester.
"Basically" the testers look like an engine compression tester that also uses compressed air to build the cylinder pressure compared to pulling the engine over to build compression.
The piston must be at top dead center and fill the cylinder with the compressed air using the spark plug adaptor that should be included. Note that some older testers only had standard plug threads and many sleds and many newer cars have metric threads. Mine has the metric and standard adaptors.
The test results are compared to the other cylinders.
The leak down can test things like a leaking head gasket that you might find bubbles in the cooling tank while testing.
Each motor will have its own specifications from the manufactures. No engine is completely sealed. Each motor will have leakage depending on miles, type of oil used ect.
I like to make sure Im comparing apples to apples, so if you do different test, make sure the motor is the same temperature between tests and record your results.
To locate a leak listen for escaping air from things like intake manifold, muffler if exhaust valve leaking (4 stroke), dipstick or oil fill port if the piston rings are leaking again 4 stroke , etc.
I will post up some pictures of doing it on my sled when my buddy finds my tester and a few other tools he borrowed.
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I get all of that.
How do u get %?
Is it timed?
5% of 130psi over 10min?
[emoji848][emoji12]
M
minus40
Well-known member
Thanks, that better than my description. I would rather copy the instructions off my tester, but its just like my neighbor to not be able to find the tools he borrowed when I need them back. Think my lending to him has come to a close. You should see how he returned one of my chainsaws lol.
Love thy neighbor must have some limits
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
Edit- both tests were done cold w 100 psi . I run polaris ves oil
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Don't you guys get it? The only way we can get reliable and consistent results is if we all buy the same leak down tester from Indy Dan!
My .02, the LARGE majority of guys and gals that ride sled either aren't mechanically inclined enough to care or just dont want to spend the money on a leak down tester for a brand new sled that has 4 years of warranty. Especially when the majority of them aren't having problems. I agree there are some major issues for a few folks, but most are out there loving this new sled.
And the leak down test will only show the condition of the top end, it has nothing to do with a bearing problem which is the biggest issue we are seeing this far. I would be curious to know the mileage on these sleds that have lost crank bearings as well. Are they all or most in break in mode yet? Aka, fail right away or not at all?
And the leak down test will only show the condition of the top end, it has nothing to do with a bearing problem which is the biggest issue we are seeing this far. I would be curious to know the mileage on these sleds that have lost crank bearings as well. Are they all or most in break in mode yet? Aka, fail right away or not at all?
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.
Dan
V
volcano buster
Well-known member
Before this thread jumps the rails, I have a question.
Is there any value to doing a leak down test on a 2 stroke with the piston moved down the cylinder just before any leakage could occur through the transfer ports? It would seem to me that this might be where more cylinder wear could be occurring compared to TDC.
I understand a crank retainer (opposite piston, clutch, ?) of some sort would need to be used to keep the piston locked into the desired location for the test to be of any use.
Is there any value to doing a leak down test on a 2 stroke with the piston moved down the cylinder just before any leakage could occur through the transfer ports? It would seem to me that this might be where more cylinder wear could be occurring compared to TDC.
I understand a crank retainer (opposite piston, clutch, ?) of some sort would need to be used to keep the piston locked into the desired location for the test to be of any use.
I bought this leak down tester for my stuff. It wasn't cheap, but for what I want it to do and tell me, it's worth the money.
I didn't pay the MFG's price but it was close to it.
Digital Engine Leak Down Tester
Instructions
I didn't pay the MFG's price but it was close to it.
Digital Engine Leak Down Tester
Instructions
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Dan, Read my whole post. And yes, Bearing problems. You have nonstop been talking about the bearing issues that have happened on this new motor. Can you explain to people why you are giving up on the bearing issues that you have been harping about since the beginning and now are jumping all over the leakdown tests that you want everyone to perform that will not have anything to do with the bearing issues. Maybe because you can't make enough money on a bearing issue that is easily remedied from the factory in 2020 and only affected a small percentage of motors? It is mighty convenient that you are now selling a "large order" of leak down testers after you posted in just about every Polaris subforum to do leak down tests....
Fyi, Since December, when I picked my sled up, I have done 3 leakdown tests. Only because I was putting a turbo on and wanted to keep tabs on it. Customers should not have to do a leak down test on a brand new motor with a 4 year warranty. PERIOD.... Those of us who are mechanically inclined will do them for piece of mind, otherwise if you are having problems, tell your polaris tech to do one when they are looking into your issue. This is why we have a 4 year warranty. I don't doubt your knowledge when it comes to engine building, but it is becoming more and more clear you have an alternative agenda which involves making money at the expense of members here.
Thanks for the info
Thanks, that better than my description. I would rather copy the instructions off my tester, but its just like my neighbor to not be able to find the tools he borrowed when I need them back. Think my lending to him has come to a close. You should see how he returned one of my chainsaws lol.
Love thy neighbor must have some limits
Harbor Freight Loves Thy Neighbor!
