Super Jet 650 to 701 62T SN conversion

[mjlvd3]

I've read most of these conversion threads from the X and pwctoday, but this afternoon I finally picked up a 701 myself. While tearing down my 93 SN for paint and turf this winter, I decided to replace the bendix and starter. To my surprise, the flywheel was locked on and no signs of coming off. This lead me to replacing it with a 701 I found on craigslist. I picked up a 94 Waveraider with a 701 62T and dual carbs and a single pwc trailer for $700. I took out the ski and it rode perfectly and started with no hesitation. The engine bay looks almost brand new and the interior fiberglass isn't even stained, yet. I'm looking to get the basics on the engine swap. To start, I want to keep this a stock and reliable 701 with mods to come down the road. What changes, if any, will need to be made for my SN.

Will I have to get an aftermarket exhaust to fit it? I have a Coffman Sizzler from my 650. Can I get a different exhaust manifold to apply it, or is it strictly a 650 add-on? The stock 701 exhaust seems incredibly large. Any direction is greatly appreciated.


I bought a bum 650 and have learned more in error than in trial, its now time to remedy that.

 

[kevbo]

Swap the engine and E-box from the raider. Your Sizzler manifold may work if there is enough extra material for the gasket but it will be close. You will need a low pitch prop and maybe raise the rev limit slightly.

 

[eeerieski]

Considering I just did a 701 shortblock swap, I can help a bit. The 650 exhaust manifold has a slightly narrower exhaust port, I dremeled out my stock manifold for a smooth(er) transition. How is the flywheel stuck? I needed the 6m6/61x stator, flywheel, and coupler from the 650, to get it off I first drilled and ground a long chunk of angle iron to fit on the end of the flywheel and bolted it on through the threaded holes on the flywheel, use short bolts as anything long will mangle the stator. I then used a long chunk of wood that fit between the coupler fingers to remove the coupler then used a 17mm socket and a breaker bar (actually a cheater pipe on normal ratchet) and unscrewed the flywheel bolt 1/4". I then used a harmonic balancer puller to apply a load of load to the flywheel and quite forcefully tapped the center stud on the puller with a small hammer. A satisfying clang occurred when the flywheel popped off and was caught against the flywheel bolt, I've heard of others having the flywheel and woodruff key fly across the room so I left the bolt in to catch it and keep the crank threads nice. My swap was mostly straightforward but I'm pretty well mechanically inclined. And man do I love my Bosch 12v tiny impact driver with a 3/8" driver adapter + a foot long 3/8 extension + a 6" 3/8" extension!

 

[mjlvd3]

Once the cover was removed, a considerable amount of water came out. It seems pretty rusted. I've had a few people attempt to remove the flywheel. The center bolt came off easily and heat has been applied by propane torch and an acetylene torch at the dealership I work at. With a flywheel pulley it still will not budge. I've counted it as a loss so I just want it off so I can part out what parts are still good. The 3 puller bolts were stripped and had to be retapped. Which is why I just started looking for a 701. Soon enough I may be selling my exhaust and ocean pro head to offset the cost.

 

[mademan9]

I did the exact swap you did. The 701 will swap over perfect. EEriseski is right about the exhasut ports, you will have to hone those out on you pipe. Other than that, everything will bolt right up. Just to let you know, that motor wont have a bunch of bottom end , compared to 61x/62t or the 61x/61x without doing a port job. But still in all , congrats on the new motor.

 

[dragginblazer]

I tossed a 61x in my 91 sn recently. I used the 650 ebox and got a newer superjet exhaust manifold off ebay.

 

[mjlvd3]

I tossed a 61x in my 91 sn recently. I used the 650 ebox and got a newer superjet exhaust manifold off ebay.

where you able to use the exhaust from the 61x? or did you get an aftermarket one? Its not looking like this exhaust will fit.

 

[djraider700]

The raider exhaust is huge and I highly doubt it will fit so u will need a stock exhaust for now or throw a b pipe on it

 

[mjlvd3]

Well I bought a 61x manifold and exhaust. Problem is the bolt sizes are different from the manifold to block. Any suggestions? I have access to a machine shop to retap the manifold to fit the bolts but I don't know if thats the best decision.

 

[mjlvd3]

Being the novice that I am, I also have no idea how to adjust the rev limiter or what to do with the lines from the ebox that hooked up to the gauge cluster on the waveraider. Can they be simply disconnected and replaced with a solid rubber grommet to seal the box?

 

[tor*p*do]

use the harness and positive battery cable from your 650 sn ebox
the raider harness is way too long and has extra connections for the dash
the battery cable is not long enough to get to the battery in the normal position
tape off the wires in the ebox that lead to the dash
just disconnect wires and reconnect to the sn harness one at a time.
battery cable is one lug swap over
this way you have the 701 cdi and it all fits nice in the sn

 

[mjlvd3]

Two major set backs today. 1 - my engine sits about an inch short of completely snug with the midshaft and backend.. 2 - I was sent a 650 exhaust manifold, which solves my problem bolting it to the block. Perhaps the entire exhaust system is a 650 because the exhaust, itself, does not appear to match up to the head. The motor mounts have been hand tightened in the pictures. 3- The 62T, being from a non premixed set up, is really giving me a headache to swap over. I have the old flywheel case from my 650 to put on this 62T, but I'm not sure what to do with the two lines going to each of the carbs. A new primer kit, I suppose. I have no clue where to go from here, especially with the alignment issue.

 

[eeerieski]

just cap off the nipples going into the carbs, or do a primer kit as you said. the couplers shouldn't be snug against each other, that gap looks a bit on the far side of ok, not sure what is up with that.

 

[tor*p*do]

pull the midshaft and make sure it hasnt been pressed back at one time
the manual has a spec for placement
it may need to be pressed back into spec
if you cannot take up the excess by pushing on the motor to the rear

 

[mjlvd3]

I have a friend with a Stock Sj that we have compared midshafts.. His measures at 2 1/4" and mine just at 2" exactly (to the bearing). That 1/4" is all I need for my coupler to fit snug like his 90 superjet. I cannot pull the midshaft to create any movement. With your direction I have switched over the necessary parts of the ebox with little difficulty. I appreciate that. My SJ used to run a Coffman Sizzler and they had shortened the outlet pipe leading to the water box. Now going to the stock SuperJet exhaust, on the 701, that outlet pipe is too short. I've looked everywhere and that outlet pipe is now obsolete. The only option is to find a used one on ebay, which I find hard to believe. Any suggestions on where to locate a replacement hose?

 

[mjlvd3]

I've been informed that the coupler fitment issue is due to a length alteration in the intermediate shaft after 93. looks like I'm now in the market for one. Also, the outlet pipe/exhaust hose can be supplemented with a radiator hose since it is now obsolete.

 

[dragginblazer]

A 61x bolted up fine in my 91 sn. You can't get 1/4" by sliding the motor back?

Sent from my Cyanogenmod G2 using Tapatalk

 

[gto0209]

just press the midshaft 1/4 inch farther forward in the housing.

 

[mademan9]

I never had that problem either with my swap. I put a 62t/62t in my sq and it fit perfect. I think something is up with your midshaft.

 

[piratelife]

i had to buy a factory pipe exhaust manifold to make the sizzler bolt up to a 62t cylinder but then ended up buying a complete b pipe and never trying it on that motor. But please update and let us no how it all works for you.