SXR Top End Rebuild

[scritch800sxr]

OK so i have an 04 800sxr the things bullet proof but its time for a new top end i dont know to much about them so i need some help. do i just have to resleeve i dont wanna bore it out at all . and would it be safe to get a new head and run higher compression on the standard size piston, and is pro-x a good top end kit or should i just get the wiseco . thanks, cory

 

[djkorn1]

Here is the deal. You WANT to bore it out. You don't need to re-sleeve until at least 2 or 3 rebuilds. If your ski is an 04 with alot of hours, I would do a crank too. SBT cranks are fine and I would go with a wiseco top end. The Pro-X tend to crack on me...
I would just contact wiseco and order the top end one size up from stock, get a gasket kit too and a crank seal kit.
The Piston boxes will tell you what to bore too, if you do it yourself, or have a local machine shop do it, make sure to use a file and take the sharp edges off of the ports.

This will save you money in the long run. You don't want to BLOW your crank, because then your taking out cases and cyllinders and thats where the big bucks come in.

 

[Matt_E]

Even if you re-sleeve,.you'll have to bore it after they're installed. The p proper way to do this is to bore one size up, like Korn said.

 

[scritch800sxr]

i talked to a guy from blowsion and he was saying that my sleeves may be 2 thin but i dont plan to bore it out to 840cc which i think he may of been thinking that. wiseco has a top end kit that bores it out to 800cc which would probably be fine.what do u think? . and is the 750 crank the same as the 800 im on sbt and thats what they have listed when i searched it.

 

[djkorn1]

Yes, the BIG PIN 750 crank is the same. Your sleeves are NOT to thin if this is the stock bore... you should have about 5 bores to go...

Yes on the Wiseco top end...you only want to bore 1 size over.

 

[X2Pilot]

DO NOT buy an SBT crank! Have a competent shop like Crankworks rebuild your crank.

Resleeving an SXR cylinder is not a simple job. The sleeve has to be machined out, it cannot be presssed out. The cost to resleeve is about twice as much as a typical cylinder.

 

[djkorn1]

Disagree...I have ran two SBT cranks in my skis with no issues. I HAVE blown two stockers.

X2Pilot, do you have first hand experience with and SBT trued and welded big pin crank?

 

[Travis]

I also have an 04 sxr. This past spring I decided to add a head and pipe combo for more power. I was going to hone and re-ring the pistons but there was some scorching on one of the cylinders. They cylinders were stock bore. I sent my cylinders to Randy at Watcon.com. He boreed them one size larger over stock. Randy did a great job and the prices were fair for somebody with his experience. He also did my girdle kit. Wiseco pistons are nice pistons but are forged. If you decide to use them you will have to make sure to warm your cylinders completely before ripping on the ski as they expand differently than cast. I used Pro-X which I think are made by the same company that makes the stock. My stock crank was still tight so I left it alone. Check out the Watcons website for his contact information.

 

[scritch800sxr]

thanks for the help Korn i had it up at erie on sunday at headlands beach waves were pretty good snapped the handlepole. lol

 

[ArtMaybee]

Ok, why does nobody mention that if you are going from stock standard bore pistons to forged... unless you have some major damage to cylinder walls, you can go with standard bore wisecos and have the cylinder honed for the proper clearance. The forged pistons require more clearance since the denser material expands more once it heats up. The hone to fit should take out any small imperfections in the cylinder and save a bore for later. I knew people who back in the day switched between OEM and forged pistons rebuild to rebuild. They got twice as many rebuilds that way.

As far as SBT cranks go, use at your own risk. Plenty of SBT motors have eaten themselves within a few hours of installation. I think the craftsmanship is fine with the cranks. The bearings and rod kits blow though. ProX pistons are pretty much the exact same piston you would get in a factory motor. They come from the same foundry as the stock pistons. I know they used to have the ART stamp just like OEM. Not sure if they still do or not. There is a reason people have called wisecos siezcos for years. If you got that route just make sure your machinist knows how much clearance they need and then check that you actually have it. Make SURE you warm you ski up well before putting a load on the motor. The wisecos are a good bit lighter than OEM pistons usually so should help with throttle response.

 

[djkorn1]

Good info, Art. The reason I use wisecos is because if they do blow, there is less chance of them crumbling and destroying your cylinder and cases.

Wiseco's have the exact bore and clearance written right on the box. I actually like the smooth throttle response of pro-x better, and they ARE less likely to blow, but when they do blow, (say water injestion) they take everything out with them.

I still run SBT cranks and will continue to... Haven't heard one complaint on ANY board or from ANYBODY about their cranks...and haven't heard complaints about their motors in about 5 years.

 

[IceRocket1286]

Good info, Art. The reason I use wisecos is because if they do blow, there is less chance of them crumbling and destroying your cylinder and cases.

Wiseco's have the exact bore and clearance written right on the box. I actually like the smooth throttle response of pro-x better, and they ARE less likely to blow, but when they do blow, (say water injestion) they take everything out with them.

I still run SBT cranks and will continue to... Haven't heard one complaint on ANY board or from ANYBODY about their cranks...and haven't heard complaints about their motors in about 5 years.

It is virtually impossible to note a difference in throttle response between seizcos and pro-x/factory kawi pistons. Pro-X or Factory pistons will not necessarily take out anything more than a wiseco would, and vice versa. If its going to blow, its going to blow, period. It all depends on how and why your motor blows up.

SBT is complete junk. By no means would I suggest ever purchasing one of their time bomb cranks. I have seen many of them snap rods and destroy engines compared to an OEM crank (new or rebuilt). I have also seen quite a few of their motors last less than 5 hours. Definitely not worth it at all.

I suggest running OEM pistons or pro-x. Kawi cylinders tend to crack between transfer ports, and it is usually hard to spot. I have seen this on many cylinders. I am sure they could still be run just fine as they were probably cracked for a long time, but I never risk it.

For crankshafts, get them rebuilt by crank works or get a hot rods crank (using oem bearings!) or just buy a new factory crank.

 

[Scorn800]

I agree with everything Luke (icerocket) said.

 

[djkorn1]

You guys have blown an SBT crank??? Never seen one go yet...My brother has built 100s of motors using them on rental skis and never had a problem. Plus they have a 1 year no fault warrantee. I haven't heard of one person who has had one fail.

The cast pistons when they blow tend to crumble sending parts thoughout your motor blowing holes in cases and destroying cranks. The Wisecos tend to stay together when the motor blows. So yes, a Pro-X piston WILL take out more of your motor.

So, I guess we completely disagree.

 

[IceRocket1286]

If I had rental ski's I would go SBT all the way, only because they are cheap and you KNOW renters are beating on the skis. If an SBT crank fails, and destroys the rest of my motor, they are only going to replace your crank, not your cases, cylinder, and head. Therefore you are screwed. I'd rather buy an OEM/Hot Rods/Crankworks rebuilt crank any day of the week before using any SBT junk.

I actually have a guy locally who rebuilds my cranks. The Hildebrand Sea-Doo Clinic. Fair prices, but he is local so it is less down time for me. Great guy, great work.

Hell SBT can't even make a flywheel puller. My buddy bought one for his SXR to change his bendix and that piece of junk stripped out within seconds, and we pre-heated the flywheel so it could pop off easier.

I rarely hear anything but complaints about SBT, and its for a reason.

SBT = Salt Bore Timebomb.

 

[djkorn1]

So you have personally or known someone who had a SBT crank fail??? I am not talking about their motors, but just the cranks. I have used two of them and they have held up perfectly and I have blown two oem cranks.

I have never heard of anyone have an SBT crank fail, ever, even on rentals.

 

[Matt_E]

Had one of their 701 cranks fail after 50 hours.

 

[IceRocket1286]

Yes, I have seen over a dozen cranks from SBT take a crap on people. It has never happened to me because I wont use their junk. When I meant motors I should have specified that it was due to crank failure, sorry.