582 alternate pistons

[109jb 181]

Soon I'm going to be doing some work on my 582 and one thing I'm looking at is replacing the pistons and rings. I see some top end kits that have spi brand pistons but they are single ring pistons. I'd prefer 2 ring pistons. I'm wondering what aftermarket pistons you guys are using in your 582s. If you have part numbers that would help a lot  

Thanks

John B

[Avid Bart 39]

I don't have part numbers, but you will want to look for Seadoo pistons. They have two rings in the pistons.

[Dusty 126]

Don't use the single ring Pistons! They make it very hard to do a huff puff test and also don't have the side port. Despite the instructions stating the port isn't necessary, it IS needed. The top bearing will start to fail in less than 200 hours.

they can supply 2 ring Pistons  which are very good quality,but make sure you use the genuine rotax cageless bearing and pin.

cheers

Dusty

[109jb 181]

Finally had some time to look.  Does this look like Sea Doo pistons that are compatible with a gray head 582?

https://www.wsmparts.com/Item/010-815PK/Piston_Kit_Sea_Doo_580_89_96_Standard_Platinum?iCartID=67780&sSessionID=ed8be7df-99c8-4821-ba6c-c8b63c2757f4#start_view

[1avidflyer 1983]

I just looked at the link you posted, and see the pistons are listed as being 76 MM.  Looked at LEAF catalog, and see they supply 75.94, 75.95, 76.19, 76.20, and 76.45 MM pistons.  Not sure how much of an issue it is using these, but it's something to think about.  I am as cheap as anyone, but when it came to needing new pistons on the last 582 I had overhauled, I went with the $230 each Rotax pistons.   And yes it did hurt to do it, but now that is one less thing to worry about when I fly it or sell it to someone else.  JImChuk

[109jb 181]

The cost is only a very small part of the consideration for me. If it was only cost then it wouldn't even be a consideration and I would just buy the OEM pistons. However, I have been a sledder for many years and have had the best luck with coated skirts and crowns.  I feel that the coatings are a big plus for longer engine life and better resistance to seizure. What I am looking for is a hypereutectic cast aluminum piston with moly coated skirts and a hard anodized crown. For sleds I like the SPI pistons and have had good fortune with them. I haven't had time to look but I'm hoping SPI has a compatible piston. 

As for the size, There are plenty of shops near me that can hone the cylinders to achieve proper clearance.

[akflyerbob 41]

I have been running the wsm sea doo pistons for somrtime now. Both standard and .5mm over with no problems. they were a perfect fit.

[Fly-n-Low 181]

The cost is only a very small part of the consideration for me. If it was only cost then it wouldn't even be a consideration and I would just buy the OEM pistons. However, I have been a sledder for many years and have had the best luck with coated skirts and crowns.  I feel that the coatings are a big plus for longer engine life and better resistance to seizure. What I am looking for is a hypereutectic cast aluminum piston with moly coated skirts and a hard anodized crown. For sleds I like the SPI pistons and have had good fortune with them. I haven't had time to look but I'm hoping SPI has a compatible piston. 

As for the size, There are plenty of shops near me that can hone the cylinders to achieve proper clearance.

I was thinking about coatings before I got to your post, if anyone flying was running coated pistons. I too run hotrod two strokes, but outboards. The last set I had done, he had a teflon coating for the skirts and a ceramic thermal barrier for the crown. He didn't do the ring lands though... I wanted them done too as an experiment for carbon build up.

[Fly-n-Low 181]

And the single ring, I have a set of Wizard pistons (http://wizardraceshop.com/) in my Merc 225 ProMax... ???? I think it is a efficiency thing... How much blow by do you get? Unless it is worn two rings would be better?

 

[akflyer 1427]

We tried the single ring SPI pistons and both bob and I had the rings fail at less than 5 hrs.  The rings were super soft and not "springy".  In under 5 hrs on both engines we did with them the compression was close to zero, and I do mean zero.

[Fly-n-Low 181]

Wow!!! That had to suck. A lot of labor and money wasted!!!

[akflyer 1427]

Wow!!! That had to suck. A lot of labor and money wasted!!!

and almost 2 planes.  The poor 582 doesn't make much power when it had the compression of a turbine.  I could use one finger to spin the prop on Bob's plane when we got it back on the ground but it stayed running.  Mine I dead sticked it in with a 20 knot tail wind and BARELY made the runway.  Had to call an emergency to clear the pattern and get the other planes the hell out of my way including a twin on short final that was headed straight for me trying to land into the wind.  Was an interesting day to say the least.

 

[Allen Sutphin 705]

Speaking of a 503 Rotax, I don't recommend coating the skirts or anything below the crown. When at operating temps there is just not enough clearance for the coating. Coating the crown is OK since clearance isn't an issue. Don't know about a 582 but I expect the same clearance issue with them as well. Rotax runs pretty tight clearances.

[109jb 181]

Clearance isn't an issue as long as it is checked and the cylinders then honed to yield proper clearance. If you just want to throw new pIstons in without checking then you are better off letting someone else do your engine.

[allonsye 85]

Maybe it's time to be looking at "alternate" engines, and by that I mean 4-stroke. I am.

[Fly-n-Low 181]

Speaking of a 503 Rotax, I don't recommend coating the skirts or anything below the crown. When at operating temps there is just not enough clearance for the coating. Coating the crown is OK since clearance isn't an issue. Don't know about a 582 but I expect the same clearance issue with them as well. Rotax runs pretty tight clearances.

I have a friend that does it. I will ask him how thick it is. It can't be much.

[Fly-n-Low 181]

Bud, who owns East Coast Powder and Ceramic Coating says:

Spec calls for .0005 to .001. But can be built up to as much as .003.