Best Pistons for 97SPX Full Rebuild -OEM, WSM, Pro-X, Weiseco?

[CASPX]

Doing a full rebuild on a super low hour 1997 SPX with the 787 in it.

Owned it since new and only had 20 hours on it but mag housing got salt water in it and corroded everything so instead of taking the risk the front crank seal held up I'm rebuilding the motor

Had a local guy Jim Yokum rebuild my crank & counter shaft (new bearings, seals, new rod bearings, new rods, wrist pin bearings, etc), bead all the components, head, lobes, shafts, cylinders, and hone the cylinders.
(PM me for his number if you're in So Cal and need your crank rebuilt, took me a year to find this guy)


This is going to be a stock rebuild that will ONLY be ran in fresh water and I want it to last a LONG time, what is the best piston to use, OEM, WSM, Pro-X, Weiseco?

The cylinders measure as follows:
PTO Cylinder -Across: 82.01mm / Exhaust: 82mm
Front Cylinder -Across: 81.98mm / Exhaust-intake: 81.97mm


Because the cylinders are original (82mm) with ONLY 1 hone on them I should run a cast piston as it will not require as much expansion clearance as a forged?

It also seems that the PTO cylinder is slightly larger that the front cylinder, any worries here?



Photos of the Job:
Before:
















After:

 

[AdamXP800]

I would stick with oem pistons.



95 XP800!!!
Keep the 2 strokes alive!

 

[AdamXP800]

[MENTION=57920]racerxxx[/MENTION] on bore sizing



95 XP800!!!
Keep the 2 strokes alive!

 

[CASPX]

Can you still get OEM pistons?

Or are they just NOS off ebay?

 

[WhiskeyD]

I'd go with oem or pro-x

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[racerxxx]

You can still get oem from the dealer. Guys list stuff nos all the time. They have no clue what nos means. They use it for new parts that your not getting from the dealer. It's typically reserved for obsolete new old stock parts that are not produced anymore. But some guys just think it's ok for any OEM part to be nos since they're selling it.

Typically, eBay will be your best source for OEM pistons at a lower price. You just have to be diligent and have patience. I typically pay buy one get one free prices for OEM pistons.

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[racerxxx]

We're your cylinders bored or just honed?

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[CASPX]

]

We're your cylinders bored or just honed?

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Just honed and just this one time.

Motor only had 20hrs at tear down, I could still see the cross hatch marks from the factory.

What size and production method pistons do you recomend?

Thanks

 

[racerxxx]

Well, what do the original ones look like? If they're clean just re ring them. If not if just look for some OEM pistons on Ebay. If I get some time tomorrow night I'll poke around

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[Hicktown]

I got pro-x pistons on my 800 rebuild and they've held up great. Probably around 50 hours of hard running so far. Cannot go wrong with OEM either.

 

[glsmohio]

how much did you have in the crank rebuild? if you don't mind me asking

 

[mikidymac]

If it is just a hone then get the standard size OEM pistons and rings and be done with it. They are the correct size and the best quality.

 

[CASPX]

Well, what do the original ones look like? If they're clean just re ring them. If not if just look for some OEM pistons on Ebay. If I get some time tomorrow night I'll poke around

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I kinda screwed the pooch on this one, Originals where good but builder told me to soak them in simple green for 1 week to de-carbon them. I left them in for 5-6 weeks and when I pulled them out the skirt chromeium surface coating was gone and they are ruff like 300 grit.

So can't use the originals and totally my fault.

So go with a 82mm OEM seadoo set?

 

[racerxxx]

Can your read the size on the top of the piston? Should read 81.89 and ELKO

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[racerxxx]

Oh, btw soak engine parts in kerosene. Your engine didn't run on simple green, it ran on a petroleum based product.

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[CASPX]

how much did you have in the crank rebuild? if you don't mind me asking

$650

I broke down the motor and took him the parts so this included:

Breaking down crank & counter shaft, bead blasting them, blasting the cylinder water jackets, the two head pieces, honing the cylinders, new nachi bearings & seals, WSM gasket & seal Kit.


Took me over a year of searching for a shop and found Jim through a referral, he has a mini machine shop at his place and does a lot of local race teams engines.

I'm very happy so far if I just had the time to get it back together.

If someone needs a crank rebuilt PM me for his number.

 

[racerxxx]

Ouch, OEM rebuilt are cheaper than that. Like $150 cheaper, with gaskets.

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[CASPX]

Ouch, OEM rebuilt are cheaper than that. Like $150 cheaper, with gaskets.

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Yea but where? I didn't want to take it to some hack shop and it took me a year to find this guy who'd do it right.

 

[racerxxx]

Just take you old crank into the dealer, give that to them. They order a rebuilt crank that comes from Seadoo. You get it 3 to 4 days later. Then while your there you could order the gasket set or shop eBay for a cheaper price for the gasket set.

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[CASPX]

Can your read the size on the top of the piston? Should read 81.89 and ELKO

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I checked and yes it says 81.89 ELKO

 

[Jetskigoodies]

Those were oem pistons from the factory then. I see them on ebay all the time.

 

[mikidymac]

The factory pistons did not have a coating on them, they are all aluminum. I could see the simple green discoloring the aluminum and it could have rusted the piston ring locating pins because they are steel.

The last OEM 787 Crank I bought from seadoo was under $400 delivered to my door, Group K charged $100 to bore and hone my cylinders to 1st over and a WSM gasket kit is $60 on Amazon. They you still have to rebuild the blalncer for roughly another $100 with OEM bearings and seals. So for $660 I got my cylinders bored not just honed, OEM crank and OEM balancer.

I say for $650 you did just fine especially if the guy did a good job and used quality parts.

I would rebuild your rotary shaft too or get one from SBT.

It can be done cheaper with cheaper parts but for my personal ski it is all OEM.

 

[CASPX]

Here are the OG pistons after 5 weeks in simple green.

 

[jhjesse]

Sorry to hijack, but has anyone had problems with WSM pistons?

 

[Matt Braley]

No they work. They are like a poor man's OEM. Obviously they are not of the same quality but they don't fail early as far as I know. I wouldn't use them in high performance applications.