Superjet motor swap.

[Daryl2cb]

So I just picked up a really nice wave venture 95 with a trailer and a 701 twin carb 62t engine. I have a 91 superjet 6m6 and was thinking of swapping the engine. So other than general engine removal, what Else needs to swap over?

Also I have a 61x full exhaust if needed. Is it possible to get the 6m6 back in the wave venture as well to unload it. It has digital gauges so I know that needs addressed to. Any help would be appreciated

 

[Daryl2cb]

So 123 views and no one knows. I was looking for information like the bed plates must be swapped. The 650 electronics will work in couch anything like that.

 

[Req]

So 123 views and no one knows. I was looking for information like the bed plates must be swapped. The 650 electronics will work in couch anything like that.

Sent you a pm about some specifics. In Summary most will swap over, electronics too but some things will need to be massaged depending on if you want to keep the couch gauges working with a 650 motor.

 

[Magnum Mike]

I think bed plates are the same for all Yamaha 650s and 701s.

your flywheel will need to match the CDI in your ebox. I am guessing the 62T engine has a 62T flywheel and the 650 has a 61X flywheel. The CDIs are different for the different flywheels so keep them matched. 61X flywheel weighs less but 62T is better spark. If you are going to keep your original ebox in the superjet put the flywheel from the 650 on the 62T engine to keep them matched.

The 62T cylinder is going to have larger threads for the exhaust manifold than a 650 cylinder. Some guys use helicoils or timecerts to make the threads take the smaller bolt. Don't drill any exhaust manifold holes larger to take the larger diameter bolt.

 

[Req]

The 650 comes with 6m6m electronics I think but the premise is the same, you have to keep the entire electronics together to make it work on other 650/701/760 platforms.

I like timecerts for the cylinder threads, they fit right in the m10 thread and bring it down to the m8 thread and are quite beefy compared to helicoils.

 

[Magnum Mike]

Yes, Req is right, and I need more coffee.... flywheel AND stator from the 650 should stay with the 650 ebox. Keep the 62T flywheel and stator with the couch ebox.

 

[Req]

Something that no one asked was what pipe? If its the bread box I would do a hard pass and find a pipe.

Cheater pipe about 300 complete (650sx based)
Riva black pipe about 350
Riva red pipe about 350
Coffmans sizzler if you can find it is about 550
FP Bpipe is about 800

Various dry pipes also exist and would probably work well but tuning, price, fitment, and maintenance scare most away.

 

[mikidymac]

The 650 CDI will have too low of a rev limiter so you will need to disable it if you keep the 650 electronics with the 701.
Also keep in mind that 701 cylinder is not the same 701 that is in the superjets.

 

[Daryl2cb]

Ok great info. So here’s the plan of attack at least so far with your input.
Pull 6m6 and remove flywheel. Remove exhaust. Stator can go with motor correct?

Pull 62t remove oil injection and exhaust remove fly wheel.
Put 62t flywheel on 6m6 and 62t couch exhaust stuff back in to couch. Oil injection swap over?

Put extra 61x exhaust on 62t from 701 superjet for now. To avoid pipe search and timeserting head. Put on 6m6 flywheel and locate info on cdi mod or buy enhancer.

I miss anything? Doing this should keep both machines as they started with all electronics working on the couch?

 

[Req]

The only downside is the lower than standard Rev limit and the pipes fitting but not port matching. Helicoils will need to be used on the couch cylinder and Im not sure how you will align the couch exhaust to the 650 since the exhaust uses bigger bolts, it will have a bit of wiggle till you crank it down for sure.

You can swap the front covers as well for the injection stuff.

Your power band is going to be a couple hundred rpm higher than the X cylinder so plan your eventual prop accordingly, something like a 9/15 would likely be a good place to start.

The bread box stock superjet exhaust is going to be a massive hindrance so also plan accordingly on that. You are looking at a ton of HP that that thing robs, up to 20 from what I can tell.

Stock waterbox is a ticking time bomb. I would also put that on the eventual list. In the interim I would grab some massive hose clamps and wrap the box so the lid doesn't go flying off. Its only glued together and its plastic/composite.

If you have steady hands @yamanube has a porting template that can squeeze some more HP out of the motor.

 

[Daryl2cb]

Cool ski has a new 9/15 hooker in it now. I did forgot the water box.

Think I just need some manifold gaskets I guess.

 

[Daryl2cb]

Any opinion of running a factory type 4 on the ski. I have one around I could use.

 

[Req]

I have read good things about them. May require some tuning but if you have it on hand I say go for it, way better than the breadbox.