SX/SXi/SXi Pro Anyone know anything about this strange 750 SXI based Motor?

[Jrod]

Looking for help on getting some information on this motor.



I have looked around online and haven't been able to find anything similar. I purchased a 750SXI ski that had a lot of aftermarket modifications, first the motor was definitely big bore and height of the cylinder case suggested it was a stroker as well. The engine top end has a Westcoast head with removable domes, however its not the typical westcoast head you see on other 750 and 650 motors. The cylinder case is also westcoat and all the through bolts which attach it to the crank case are internal like you would see on a Dasa. The piston size is 89.5mm and the stroke looks like it is about 78-79mm which puts the displacement around 980cc.

Other main performance mods that the ski came with:

Factory Wet Pipe w/ resonator *(thanks The Buzzard)
Dual 46MM buckshot carbs on R&D intake
Aftermarket ignition w/ lightweight flyweel (Bad Bone or something like that)

The ski pretty dirty when I purchased it however it did start up without too much trouble and ran fine. I have stripped the hull, disassembled the motor, and now I am just waiting to paint the ski after I finish the footwells.

If you have any information regarding the motor setup please let me know.

 

[SmittySX]

Interesting..

 

[TheBuzzard]

thats a factory mod wet pipe. no longer produced. as old as that setup is, its probably a 4 or 6mm stroker setup. if its a westcoast head, then its a westcoast big bore cylinder under it. is it a reed induction cylinder , with the crank case intake tract blocked off? or what? nice vintage stuff that there isnt much of out there. as costly as it was back in the day, not many were sold. dont blow it up or it will all be trash can filler.

 

[linden]

is that an external fuel pump to the left of the ebox?

also is that an aluminum gas tank with a sending unit at the top of the picture?

 

[Jrod]

Thanks for the information I really appreciate the comments.

Yes it is a westcoast head with the west coast cylinder, its marked in a couple spots with the standard westcoast logo. The cylinder is not a reed induction if I understand that correctly. The reeds are still in the crank case, and the crank case intake tract is not blocked off. It is definitely vintage and interesting, I agree that if it blows up there's definitely no finding parts for it.

 

[vodie0212]

Would love to see more pics of this!

 

[Jrod]

is that an external fuel pump to the left of the ebox?

also is that an aluminum gas tank with a sending unit at the top of the picture?

Yes that is an external fuel pump for the carbs, the crank case has two pulse fittings, one that split off for the dual carbs, and the other went to the external fuel pump.

That is an aluminum gas tank with a sending unit in it... I do not know what someone was thinking on that one but it looks like they were just learning how to weld when they built it. The sending unit and wiring inside the ski was a mess, they cut a nice 1-1/2 hole in the front of the chin pad for the fuel gauge, imagine smacking your head on that... I have a new tank for the ski that I will be using, as unique as the old tank was it was ugly, heavy, and most definitely leaked.

 

[camojoe]

LMFAO!!!!
Before I even read the post, I looked at the pic and I thought to myself this looks like a ski the buzzard would find, some sunken majestic treasure that only the pirate himself could find....then noticed your in San jose

Classic!

Looking for help on getting some information on this motor.

View attachment 212818

I have looked around online and haven't been able to find anything similar. I purchased a 750SXI ski that had a lot of aftermarket modifications, first the motor was definitely big bore and height of the cylinder case suggested it was a stroker as well. The engine top end has a Westcoast head with removable domes, however its not the typical westcoast head you see on other 750 and 650 motors. The cylinder case is also westcoat and all the through bolts which attach it to the crank case are internal like you would see on a Dasa. The piston size is 89.5mm and the stroke looks like it is about 78-79mm which puts the displacement around 980cc.

Other main performance mods that the ski came with:

Factory Wet Pipe w/ resonator *(thanks The Buzzard)
Dual 46MM buckshot carbs on R&D intake
Aftermarket ignition w/ lightweight flyweel (Bad Bone or something like that)

The ski pretty dirty when I purchased it however it did start up without too much trouble and ran fine. I have stripped the hull, disassembled the motor, and now I am just waiting to paint the ski after I finish the footwells.

If you have any information regarding the motor setup please let me know.

 

[Jrod]

Haha, I like the "sunken majestic treasure that only a pirate himself could find" comment. When I pulled it apart it look like it had been sunk at the bottom for a while, but inside the motor surprisingly clean. Ill take some pictures of the cleaned parts that show a little more detail and post them tomorrow. Here are a couple other pics I took upon first inspection. And yes I am flipping off the motor in the first pic... not intentional.

 

[TheBuzzard]

thanks camojoe,i'll take that as a compliment. i wish i found this gem. i'm sure he picked it up for ass wipe money. i flip kawi stuff off also, intentionally tho.

 

[smrbum]

i ran a couple of these motors and have one for sale,they are pretty rare and run strong

 

[camojoe]

Compliment all the way. Stop replying cause your messing up your post to thanks ratio hahah

thanks camojoe,i'll take that as a compliment. i wish i found this gem. i'm sure he picked it up for ass wipe money. i flip kawi stuff off also, intentionally tho.