Super Jet 90 sj, 650 looking for a little more lowed snap

M

millnoff

Location
minnesnowda
Hey i was just wondering what you guys think would be the best bang for the buck upgrade for my 90 sj 650 to help with a little more low end snap? it has a grate, and impeller (was on when i bought it so dont know brand or pitch), everything else is all stock. the motor is strong, 140-145 psi in both cylinders and it runs good just needs a lil help out of the hole lol

do f/a's do much for the ole 650's? or would i be better off going for a pump cone or something? im new to the sj's so any advice would be great!

thanks,
-Jesse
 
eeerieski

eeerieski

Location
NW PA
Upgrade to a 701, I did and sold the 650 engine for a net upgrade cost of $50. FA does very little for low end. Look for a sizzler pipe, they fit on the 650 and 701 engines. milling the stock head will help, use a higher grade fuel though.
 
M

millnoff

Location
minnesnowda
right on, idk if i want to sink tons of money into this old ski though? but if i can do it for cheap then why not. so 701 first it is lol. where is the best place to find one/build one? on here im guessing? do you need any different electronics? 701 pipe? or anything like that or is it all the same between the 2 motors?

so getting a freestyle cone is a waste of the 55 bucks tho?

thanks,
-Jesse
 
M

millnoff

Location
minnesnowda
So im going to resierect an old post haha, if i wanted to swap in a 701 would it be easier to do a 61x or 61t motor? do they use the same electronics and what not? is it just the single/dual carb difference ans some porting diff?

thanks for any help, im going to try and start getting things ready for the swap.
-Jesse
 
WAB

WAB

salty nuts
Location
coastal GA
do a search for 61x vs 62t. Lots of threads to read through....

Find a cheap Yamaha couch with a 700 (701) or a 760 motor to transplant into your ski.

millnoff said:
So im going to resierect an old post haha, if i wanted to swap in a 701 would it be easier to do a 61x or 61t motor? do they use the same electronics and what not? is it just the single/dual carb difference ans some porting diff?

thanks for any help, im going to try and start getting things ready for the swap.
-Jesse
Click to expand...
 
Last edited:
M

millnoff

Location
minnesnowda
WOW overload of information!

So what ive figured out is that i have 3 options, 61x, 62t, or 62t cases with 61x topend. seems like all 3 of the options would work ok for me im not extreme or anything lol. but my riding is more jumping wakes/waves so more lowend would be better than topend for me.

so i guess id like to have the smooth power, and well power potential of the 62t but from what ive read is there not as hard hitting on the bottom end as the 61x or 62t/61x mix.

so if i did the 62t cases with 61x cylinders i guess im a little confused on a few things. Is it possible to run the stock 62t jetting with the 61x topend? or does it take some tweaking? I want to get it all running and working on stock exhaust so would i need a 61x or 62t exh or are they the same thing?

-Jesse
 
WAB

WAB

salty nuts
Location
coastal GA
millnoff said:
Is it possible to run the stock 62t jetting with the 61x topend? or does it take some tweaking? I want to get it all running and working on stock exhaust so would i need a 61x or 62t exh or are they the same thing?
Click to expand...

just about any option is going to need some carb jetting/tweaking.
The 62t cyl uses larger exhaust manifold bolts. If you use the 61x manifold, you can drill the manifold bolt holes out for the larger bolts on 62t. Or, you can use stainless Timecerts. Do a search for '62t manifold bolts'

http://www.x-h2o.com/threads/89401-...-61x-61x-64x-62t&highlight=62t+manifold+bolts

http://www.x-h2o.com/threads/74194-701-vs-760&highlight=62t+manifold+bolts

http://www.x-h2o.com/threads/17357-waveraider-701-parts-swappable&highlight=62t+manifold+bolts
 
You must log in or register to reply here.
Top Bottom