Leakdown test results.


8 replies to this topic
  • CanadianWR450

Posted October 30, 2009 - 09:07 AM

#1

I have dug through the manual, and can't find what I'm looking for, and I have searched on here, and can't find exactly what I'm looking for either...

I had a leakdown test done, and the results came back as "5%", which, according to the dealer, is good, and shows that there is no issues (compression wise anyway), or compression loss....

It's not that I doubt the dealer, but I have heard "mixed reviews" on their abilities lets say, so simply looking for some confirmation on this reading and what it means.

  • KJ790

Posted October 30, 2009 - 09:15 AM

#2

On most engines a leakdown test should be below 10% loss when the engine is fresh. If an engine has time on it and has begun to wear then up to 20% loss can be considered acceptable. If you are at 5% loss then the ring seal and valve seal is pretty darn good.

  • CanadianWR450

Posted October 30, 2009 - 09:26 AM

#3

Thanks!
Exactly what I was looking for..

Unfortunately, I still have to tear into it due to a oil consumption issue, but this at least makes me feel better. If you search on here for a thread by me called "How to check oil pressure?", you will see what I got going on. Dealer is in full agreement in regards to what I think happened (should have replaced cylinder/piston last year, and didn't), and it can still use oil via the cylinder/rings even with no compression loss.....

Lesson's learned as they say.....eh.

If you do check that thread, the diagnosed the "noise" I heard as suspected play between the water pump shaft, and where it goes into the counter balancer

  • 123BigcoopDawg576

Posted October 30, 2009 - 10:19 AM

#4

Dealer is in full agreement in regards to what I think happened (should have replaced cylinder/piston last year, and didn't)


I wonder if they are in-agreement because if you buy new parts (assuming from them) that they will make money. :ride:

There is no need what so ever to replace a jug that is in spec. A simple pass of the hone is all that is needed.

Your oil consumption issue is because of something else not because you or your dealer think you should have replaced the jug on a rebuild....:smirk:

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  • CanadianWR450

Posted October 30, 2009 - 01:26 PM

#5

Well, it was me that went down that road on my own way before ever getting the leak down test done, as discussed in the other thread....

The conclusion I came up with on my own (without tearing it down) is that if the cylinder is to the point where you can not see any of the factory cross hatch left, it should be replaced, or re-plated, and I did reuse this cylinder with just a hone, and rings last year (along with seals, gaskets, etc...)

Of course, I'll be tearing it down before buying anything, and the cylinder (if needed) will not be coming from the Dealer, and they are well aware of this.

It boils down to I'm trying to figure out why I only got 2,000 - 2,500 Km's out of a "freshing up" of the top end.

Hopefully I'll know why for sure when I open it up this winter, but at this point, I'm speculating that I should have replaced (or re-plated) the cylinder, and replaced the piston last year, but didn't

  • 123BigcoopDawg576

Posted October 30, 2009 - 01:32 PM

#6

I'm speculating that I should have replaced (or re-plated) the cylinder, and replaced the piston last year, but didn't


Any why are you speculating that? I rebuilt my Dad's 06 with 13K miles on it and all we did was hone the bore. 3000 miles later and his is not burning any oil.

I just find it extremely far fetch to believe that your bore is the cause of your oil consumption (assuming it was in spec and honed correctly upon the rebuild)

  • CanadianWR450

Posted October 30, 2009 - 01:54 PM

#7

Any why are you speculating that? I rebuilt my Dad's 06 with 13K miles on it and all we did was hone the bore. 3000 miles later and his is not burning any oil.

I just find it extremely far fetch to believe that your bore is the cause of your oil consumption (assuming it was in spec and honed correctly upon the rebuild)



Mine is a 04, and I have no idea how many miles are on it. What I do know for sure, is that there was no cross hatch left.

I'll be honest here, it was not me personally who measured the bore, etc, but the person who helps me work on the bike, who has rebuilt many bikes, and who I trust, and even he said it was "close" ( borderline).

We tore it down because of exactly the same symptoms I have now:
- slight smoke at high rpm
- some oil consumption, varies on how hard, or easy you ride the bike. Mellow sight seeing ride...NO oil consumption, run it hard, it uses oil.
- no performance loss that I can tell.

We know the rings were worn when we got into it. So was the timing chain. One valve needed slight adjustment. Cylinder was as stated above, piston looked good.

New timing chain, new rings, valve seals and guides, ball hone to seat the rings, and new Hotcams (Just because).

did not burn oil or smoke at all for the 2,000+ km's....then it started to exactly as last year.

Again, I'm not saying I KNOW this is the issue, I am SPECULATING this is the issue...

Let me ask you this:
When you rebuilt your dad's, could you still see any of the original cross hatch left?

  • 123BigcoopDawg576

Posted October 31, 2009 - 07:11 AM

#8

Let me ask you this:
When you rebuilt your dad's, could you still see any of the original cross hatch left?


Most of the cross hatching was glazed over. Thus a quick pass of the hone and we were back in business.

If I read your post above correctly, you did not replace the piston? If that is true, I would say that is more likely to be your problem then the bore

  • CanadianWR450

Posted November 01, 2009 - 07:53 AM

#9

Correct, and my cross hatching was gone, not just glazed over....
So, I still think I'm on the right track...tear down, make sure there are no surprises, and if not, new piston, rings, cylinder, valve seals/guides, etc, and good to go, and I'll chalk it up to a learning experience.....




 
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