Ski-Doo 600 Rebuild - Base Gasket Leaking

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sledheadjoe

New member
I just rebuilt my 2004 600SDI over the summer from the crank up. No failure, just preventative as the inner PTO crank bearing seal failed a leak down test. I used a Winderosa base gasket and installed it dry (I know there are a lot of debates on this but I followed Bill Cudney's advice). Cylinders and crank case surfaces were spotless; no scratches, old gasket contaminants, residue, etc. Installed Y pipe (loosely) before torquing jugs to ski-doo specs. Put everything else back together and installed back in the chassis. About a month ago I topped up the fluids including anti-freeze but didn't get the chance to start it up... last week I went out to complete the first start-up and did a final "once over" before pulling the cord. I found a small amount of anti-freeze leaking down the case from the base gasket. Not a lot, just a bit of dripping with a couple small puddles in the belly pan. Here's what I want to know:

1. Is it likely that the gasket leaked because I filled the fluids and let it sit for 3 weeks without starting (and hence warming) up the engine to "seat" the gasket?
2. Do I need to rip the top end off again and replace the base gasket or will it seal properly if I just go ahead and start it up?
3. If there's coolant dripping down the outside of the block, it's likely there is coolant in the bottom of the case too. Is there a way I can get this out before starting? I'm thinking of pulling the plugs and pulling it over until no more coolant comes out. Will any residual coolant create a problem on start-up? Or will it clear out after a few seconds of running?

Thanks in advance for any help!
Joe
 
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snowfreak56

Member
Not trying to be smart but if you feel lucky pull the plugs pull it over a few times and see if it blows any coolant if not put plugs in and fire it up.But if it was mine and i knew it was leaking i think i would bite the bullit and pull the jugs and find out why, and if i didnt find anything i would go back together with a new base gasket.And i personaly use a lite coat of 2stroke oil on the gasket.Good luck with what ever you decide.
 
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dab102999

New member
I have been in enough doos to say if u even think there is fluid in it pull it out and strip it...it will wash that iso flex out.
 
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dab102999

New member
R u sure it is coming from base gasket and not a tight water hose....or water pump area?????.... If u do tear down again i use base sealant....1104 or equivilant....
 
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skeeter2010

Member
Why not clean everything up check the torque the bolts and pressure test the system and see if it is sealed up, you could even get some dye and a black light.
 
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mjkaliszak

New member
Tear it back down... F in BRP... Here is a good link for a DYI leak test. I just did this, I can hold the 3.5 psi for the 5 minutes. I found all kinds of things that tick me off. Like case/casting perosity, new carb boot was not " packed out " enough during the overmold process, both of these caused my slight pressure drop during test. ADDITIONALLY... I found what caused my burn down with this, it was not alot of money since I had several " leak down " guages. The entire problem with my sled is due to many things mostly ( BRP ) but after spending 1300 on parts I'm not chancing anything. Remember " Murphy's Law " , why chance it ? Tear it down then do the leak test on reassemble just to make sure. My dam doo just cost me a ton of money, and we caught the burn down quick.... I wouldn't chance anything anymore, other wise " WE " end up paying. AND with the price of sleds parts .... enough said !

Here is the link, hope you use it.

http://www.dootalk.com/forums/index.php?showtopic=258932
 
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sledheadjoe

New member
Thank you everyone for all you input! This is what I was looking for. Some additional comments...

snowfreak - thanks for the reality check. I'm not sure at this point in time it's worth half-a**ing it. I have too much time into it now.

dab - how will the coolant get past the bearing seals to wash out the iso-flex? Also, I'm sure it's not coming from a hose (checked every hose connection) and it's leaking too high on the exaust side of the jugs to be from the water pump. Also, do you use 1104 as a base gasket dressing or as a crank case sealant? I used loctite on the crank case, nothing on the base gasket. I do have 1104 in the tool box but I'm not planning to split the cases again.

skeeter - my main concern with doing a leak test at this time is that the motor has not been started yet. I think the base gasket will likely leak as it has not been heated and properly sealed. Hence my suspicion that this is why my leak occured in the first place and perhaps starting it up may be enough to fix the problem.

mjk - I performed that exact leak test in the spring. That is how I discovered the inside PTO bearing seal was shot. GREAT test!! On the rebuild, I did everything including crank bearings, pistons, rings, all seals & gaskets, VF3's and Cudney head. This engine is fresh and just buttoned up. I did find lots of porosity, etc. also. My crank run out was within 0.001" though so that was a bonus.

I'm heading to the shop this weekend to have another look. I'm bringing a spare base gasket just in case. Will let you know if I find anything.

Thanks again everyone.
-Joe
 
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mjkaliszak

New member
Here are a few leak spots on my rebuilt motor. I happened to buy a new BRP boot and the f-er leaked, not much but I'm meticulous. I did find the weakness in the casting producing leakage. Not to mention a very small leak around the exh gasket. I went over this with a fine tooth comb . My doo was originally built on a snocheck, at the factory the reeds had some flash around the molded perimeter and were stuffed in the boots thus leading to a preloaded stress on them causing the leak. Not that they wouldn't have failed anyways but....
As far as the base gasket leaking before starting the motor ??? mine does not, I have leak tested it 10 times looking for the smallest bubble when spraying it with simple green. I opted to go with the Boyesen reeds after my experience with the doo boot leaking. I lose 1.5 #'s over the 5 minutes so that's why the repeated leak testing. From your last post , I assume you increased the base gasket thickness from stock ? I think that was recommended on the 600's also ? I feel for you, believe me, I want to put this back together and have it run thousands of miles... I have .003 on the TIR but that was not pulled out of the case and measured like I would in a toolroom. Never built a grenade, but never accomplished a build quickly and there is no way I could ever make money at it. The last thing I always have done ( after emptying the fuel ) is fill with coolant , gas it , and start it. I never waited with it loaded with coolant . I thought your question was a valid one, something that made me think about it 2X's.In fact I can't even explain why I do things the way that I do, I never thought about it until you posted this topic.

Just for the record, I do use Three Bond frequently, I didn't use it on my base gasket but love it for chain cases. I did start to reseal the leaking area's (with new gaskets ???) with the permatex ultra copper. The job turned out to be a nightmare, I even had to buy a cylinder. I caught this one quick we pulled the belt and towed it bace to base camp. When I took the cylinders to be honed by my budd, he found 2 small hairline cracks going fron the exhaust valve orfice to the 2 small exhaust ports.... I mean how weak are there things ??? In the pic with my finger, is where the upper case was leaking slightly, right in the ribs... Sorry, I had to vent !!!!

Thanks

Mike
 
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sledheadjoe

New member
Yes, stock base gasket was a 6 hole (0.6mm) and I put a 0.65mm back in. And I can relate - I would never make money at this as I am just too meticulous with checking and then checking again. Have about 50 hours into the rebuild, not because I don't know what I'm doing but because I do everything the best I can. I applied permatex ultra copper on the exhaust gasket upon assembly to ensure no leaks but nowhere else. Was considering dressing the base gasket with Hylomar if I can't get the leak to stop.

Still not sure if letting the fresh build sit for 3 weeks with coolant in it is what caused the leak but I will certainly never do that again in the future even if it wasn't.

I added a picture of the void in the case casting I found when I pulled the crank (outer MAG bearing).
Void.jpg

Joe
 
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snowfreak56

Member
sledheadjoe said:
Yes, stock base gasket was a 6 hole (0.6mm) and I put a 0.65mm back in. And I can relate - I would never make money at this as I am just too meticulous with checking and then checking again. Have about 50 hours into the rebuild, not because I don't know what I'm doing but because I do everything the best I can. I applied permatex ultra copper on the exhaust gasket upon assembly to ensure no leaks but nowhere else. Was considering dressing the base gasket with Hylomar if I can't get the leak to stop.

Still not sure if letting the fresh build sit for 3 weeks with coolant in it is what caused the leak but I will certainly never do that again in the future even if it wasn't.

I added a picture of the void in the case casting I found when I pulled the crank (outer MAG bearing).
View attachment 27314

Joe
Click to expand...
I am woundering why the leak myself, and also woundering about the 3 week set time haveing something to do with it, but my theory there is it should have sealed.I wounder about the winderosa base gasket but alot of guys use them.There is also pros and cons on the thicker base gasket personaly i would go back to the 6 hole that was on it.If it wasnt for the possibility or likely hood of coolant being already inside the crankcase running it to see if it sealed wouldnt bother me ,but with there likely being coolant in the crankcase that thought just makes my skin crawl.I have never used sealant on a base gasket but always put a thin coat of 2stroke oil on them and have never had one leak.Good luck.Keep us posted.Tom
 
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sledheadjoe

New member
I have been in contact with Bill Cudney a few times throughout my build to get some tech tips. I called him to discuss this issue and he suspects the leak was in fact from sitting without start-up to seal the gasket. He also suggested that I could pull the plugs and anything inside the case should blow out with a few pulls. Just keep pulling until nothing more comes out... Bill really knows his stuff and I trust him. I do plan on stopping in at the Doo dealership on the way to the lake this weekend to discuss with one of their mechanics and get a final opinion. I have the head back off and most parts disconnected so it wouldn't take long to pull the jugs and do it right.

Will let you all know how things go early next week. Thanks for all the replies!

-Joe
 
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