96 XP, Rossier Pipe, Mod Questions

[Pwnage1337]

Hey guys I have a 96 XP, just installed a new SBT engine that has 15 hours on it. It runs great, SBT was awesome to work with.

My goals for this ski are just a reliable pump gas friendly ski. Not looking for anything crazy, at the end of the day I think it would be cool to hit 60 MPH. I have it on GPS pulling 57-57.5 depending on water conditions right now. The only mod the ski currently has is an X0 impeller. It pulls 6700-6750 with the X0 in good water. I plan on picking up a 97SPX waterbox for it. The ski is still oil injected, running BRP XPS Oil.

Moving on,

I just scored a Rossier Pipe for my Ski. A few questions I have are:

Can I run the stock airbox, or is it highly recommended that I get Aftermarket Flame Arrestors?

Should I consider going to an aftermarket head, with the understanding that I will have to run premium pump gas? I currently run the cheapest Ethanol free gas i can find, which is 88 octane. Paying for 91 doesn't bother me and is not a factor.

I understand that running the rossier pipe requires plugging the waterbox. I have seen the Jetworks flow control valves, and haven't seen anything bad about them. Would it be wise to run one, or should I spring for an ECWI kit right away?

I found some good jetting info on the pipe that i'm going to give a try. Ordering Jets from OSD today. If i am able to run the stock airbox, I'm sure it would change the jetting requirements a little bit so i will order a few jets sized around the recommendations i've found.

Any input is appreciated!

Thanks

Jeremy

 

[Pwnage1337]

Also, does anyone suspect that I will be hitting the factory rev limiter with the new setup?

I reached out to Matt Braley and he has rev limiters for sale so I can get one if I need one.

 

[mikidymac]

Just to give you a fair warning, the SBT engines are a good stock replacement and that is it. They are really not up to performance mods due to the quality of materials and machining designed to lower compression and prevent warranty claims.

 

[Pwnage1337]

SBT engines have lower than stock compression by design? I didn't know that. I will check my compression tonight. It makes sense why they'd do that

 

[mikidymac]

They cut the heads to lower compression to reduce warranty claims.

 

[Pwnage1337]

Good information to have. Thank you sir.

Is the rotating assembly noticeably worse also? I would imagine they are rebuilding BRP cranks, using their own brand of pistons, and probably their own brand of bearings.

I'm going to proceed with Mods as intended, I didn't know that they intentionally set them up that way but I understand their reasoning behind it.

 

[mikidymac]

Don't get me wrong, SBT is fine for a "stock" rebuild but es, they use their own pistons, bearings and rods. The quality is fine but not OEM.

 

[Pwnage1337]

Wouldn't cutting the head increase compression?

I could see the overbore causing an overall drop in compression, but milling a head would increase compression, right?

I'm going to roll the dice and say another 400 RPM (i hope i can turn 7100) probably won't kill it

 

[mikidymac]

No, they cut material out of the combustion chamber that raises the volume and lowers the compression.

 

[Pwnage1337]

Makes better sense that way. Thanks for your input

 

[mandriva]

I use rossier pipe 787 with head mod 92 (175 psi/043 squish) jet kit rossier/flames arrestor/ primer kit/ true 40 carburetor/ rotary valve 163 with SOLAS X 0 , i got rpm 7100@7200 rpm, i hit 59/60 GPS smartphone

 

[mandriva]

You need check mid jet pipe , with ECWI you need 90 and without ECWI 110@115
200 stinger

 

[Pwnage1337]

200 seems big in the stinger compared to some of the other posts I found. They were recommending a 150-160. Do you run a 200 only with ecwi?

 

[Pwnage1337]

Anyone else have input?

Follow along as i purposely void my SBT warranty by bolting on a different head, add a rossier pipe, and spin the fucker to 7000.

Yee Yee!!

Uncle Ricky would be proud

 

[mandriva]

yeah! for safe use 160 stinger, 115 without water injection and also remove the rave valve water on muffler and block the hole! i have instructions rossier!

 

[mikidymac]

Anyone else have input?

Follow along as i purposely void my SBT warranty by bolting on a different head, add a rossier pipe, and spin the fucker to 7000.

Yee Yee!!

Uncle Ricky would be proud

Good luck with it and hopefully it holds up. SBT isn't known to be the best quality especially for a performance base. Let's see what happens...

 

[Pwnage1337]

Prob just a bunch of kids who don't know what theyre doing ruining engines and blaming it on bad manufacturing. Lol!! Just kidding. I know it's not 'the best' but I don't have 15 months worth of patience waiting for someone to rebuild a 2 stroke so I have to work with what I got

 

[mikidymac]

Or you could rebuild it yourself in a couple weeks using high end parts.

 

[Pwnage1337]

Probably what I'll end up doing next winter. I want to try to get one full season out of it before I tear it down

 

[fatblockabody]

Lot's of good info here, I'm new to 2 stroke ski's but not to engines and performance stuff (drag racing and associated fab work) and looking for similar goals with my 97 SPX.


Just curious, why are people switching to the SPX waterboxes?

 

[Pwnage1337]

They apparently flow easier. If you look into an SPX box they have a nice tapered entrance, the stock 96 box is not. The spx box is a little louder too