650/X-2 more power?

[Ghetto Jet]

My friend just recently purchased a bone stock 1990 x2 and he would like to have more power. He would like to be on par with my superjet power wise. (2000 superjet, ada head 35cc and b pipe)

I suggested that he try to max out his 650 as much as possible, new intake manifold, a 44 carb, higher comp head, pipe, prop etc. Is it worth it to max out the 650 engine? If not, what would be the best route to go... kawi 750, seadoo 717? Can the 650 pump handle the power of the bigger engine if propped correctly? Lastly what would I be getting myself into with an engine swap? I for some reason highly doubt it is just going to drop right in.

on a side note I had an absolute blast on that x2 today. I was just going to take it out to make sure everything was running right and I just couldn't make it back in. My friend didn't look to pleased on the dock.

 

[Cannibal]

Any 750 or SXR 800 will bolt right in. E-box needs to be dealt with (either swap in the 750/800 box, or modify the engine to accept the 650 electronics). Dual carbs are a tight squeeze, but do-able. 650 pump is very close to a 750/800 pump (same diameter, a little different center), once you get a larger engine, call impros and have them cut a Hooker prop down to fit or run a stock SXR prop that is cut down. Also, a head, porting, Factory Pipe, etc, can all be done to put out some damn good power.

I'd just skip the 650 engine all together. Don't throw any money at it if he eventually will go up to a larger engine. Just ride it as is and start buying some parts until you have what you need for a full winter rebuild/re-power.

 

[Crab]

750 can be a handfull at times

 

[Ghetto Jet]

Would a 94 kawasaki 750 sxi, or a 98 sxi pro be a good ski for a donor? If so we are going to go buy one tomorrow. 900 for the sxi and 1200 for the sxi pro.


Your picture sold my friend.

 

[Vumad]

I think those 2 motors are pretty much the same. You could also buy the conversion plate (Crab sells it I think) to bolt in a Yamaha motor.

 

[Cannibal]

94 is an SX so its a small pin engine, lower port timing, more bottom end, but single carb. SXi pro has big pin engine, little more overall horsepower, but not as good on the bottom end, has dual carbs. Crab and I both run a small pin, I have a Blackjack 44 on mine, he's running OE SXR carbs.

I know guys running the big pin engine and are very happy with it. So in my opinion, I would buy whatever ski is the better deal and in better shape. You will be able to recover a good amount of the investment by parting it out, so the one with more valuable parts would be my choice. But stock for stock, go with the 94.

 

[tor*p*do]

94 motor is 4 years older
cost, compression and motor condition
would make this call IMHO

 

[Ghetto Jet]

I am going to go take a look at the 94....it has no spark right now but it also comes with a 2 place trailer and an extra battery. If spark is the only issue and I can get him to drop his price a little it is most likely going to come home with me today.

 

[WB1994]

650 power baby !

 

[jetman624]

The '94 will have a small pin motor, which has porting that lends itself to a more even power band. The Big pin motor out of that sxi pro will be a little laggy on the bottom in comparison. I have small pin 750 is both my X2s

 

[Jayski]

Mines pushing good power- 750 small pin bored 2mm, wz total loss

pritty much done everything i can in chase of more power and turing that power into thrust.
http://www.x-h2o.com/threads/63642-750-X2-build.-allot-of-pics.

 

[WB1994]

man i just got a pjs section 3 pipe man it's definately 36%power increase! Still need to mill it! and prop it! but a 750 is a easy way to get more power! i would get a pjs or factorypipe there probably the exact same nearly.That big pin SUCKS FUEL AT 3 dollars a gal

A pjs 700cc cylinder is stupid too much

Nowhere near the same. PJS is bottom of the barrel , especially if your putting it on a 750.

 

[shawn_NJ]

WB is dead on, old school PJS pipes do not even come in the ballpark of a ported FP SJ limited chamber for bottomend power. The PJS cylinder is an old school racing setup that needs custom impossible to find pistons and will not even come close to any well setup modern 61x setup on bottomend. Forget HP #'s as there all BS, and ride a well setup modern big bore yamaha.....I've ridden a PJS pipe and cylinder and at best its a topend only racing config.

 

[Jayski]

jae

if i did it all again i would had put yam power in my ski for sure... My x-2 is quicker on the top but the power delivery is much better in my 61xSJ and the motor is pritty much stock besides the ignition and pipe.

 

[shawn_NJ]

yamaha's have weak motor's period the reason they don't win titles. They are the most comfortable to ride though. forget the hp number's! what is supposed to move it magic and 20k

My point about HP is that there are no dyno charts comparing different motor setups. And I'm not arguing kawi vs yam either. If I was into racing then I agree with you, I'd be running an sxr motor too. But after spending alot of time on my friends full PJS 650sx and pjs 550...that the usable powerband on the PJS 700 motor was aweful. If you want a topend only setup then I guess there cool, but for a rec/freeride ski the setup kinda sucked. I've sunken a ton of money into my sxr motor and ran an 800 with race gas 215psi, the sxr motor never came close to the bottom/mid power that my pump gas BB 61x has. SXR motor def made more power on topend though. As far as the pipe discussion. I ran a PJS pipe on an otherwise stock 650 x2 years back. Bottomend power was not even close to the factory pipe BPipe limited chamber. I had to prop up from the 8/16 to a 9/17 when I put the FP on, because it was spinning the 8/16. The PJS ran fine on the 8/16.

 

[shawn_NJ]

It doesn't really matter to me I like both of them. In salt I could'nt really see waisting more than 3500bucks on a machine that's gonna just get wrecked from salt anyway

LOL! Agree with you there. (The salt wrecking everything)

 

[SUPERJET-113]

yamaha's have weak motor's period the reason they don't win titles.

:haha: :haha:

 

[2XLR8]

I don't see the reason to buy another used unknown condition ski to take out the engine only to find out you need to sink money into it as well. If you get a 750 you must run the 750 ignition with the heavier flywheel or tear apart the crankcase to machine the front to take your 650 stater. At this point you will more than likely find that it is freshening up time for your newly purchased 750 engine. That there brings more money into the equation.
If your 650 engine is in good shape just port it install a good pipe and a super bn carb and you are done engine wise. The better pipes are the Factory pipe, coffmans all aluminum unshortened,the last mariner pipe which was made by factory pipe and even the westcoast with the limited chamber. You should be able to purchase used parts at decent deals on line. An old 15 degree straight pitch,13/16 or a new 12/16 big hub swirl would work good.
If it was me I would take the money that I would spend on the 750 and buy the parts that you will STILL need to buy anyway.

 

[WB1994]

yamaha's have weak motor's period the reason they don't win titles. They are the most comfortable to ride though. forget the hp number's! what is supposed to move it magic and 20k

But they do backflips , lol.

 

[WB1994]

It doesn't really matter to me I like both of them. In salt I could'nt really see waisting more than 3500bucks on a machine that's gonna just get wrecked from salt anyway

Surfs the most fun you can have on a machine and you want to ride a sh!tbox?
14 or so years riding surf in the ocean and nope , salt hasnt wrecked any of my machines. Rinse with a hose and lots of WD40 , thats it.