Motor swap, 650 to 701

[mademan9]

I just won a 701 62t From ebay, last night. It suppose to come in sometime next week. I have a 650 with a few after market parts. Protec pipe. And mikin dual carb. So my question is what would I need to do a complete motor swap. I read that everything is compatible , but is there anything else that I should know about before making the switch? Thanks before post.

 

[Matt_E]

It depends on what the 62T motor comes with and what topend it has (61X or 62T).

Do you know?


Regardless, nearly all parts are interchangeable. You can run the 650 electrics if you run stator and flywheel together. The 650 CDI will work, but the rev limit is so low that it will limit the motor.
If the topend is 61X, then your old exhaust will work.
If it's a 62T topend, then you will need different exhaust bolts or inserts for the cylinder to make the old bolts work. However, the manifold may not line up properly with a 62T cylinder - I am not sure about that.

The dual Mikuni carbs should work if you have the right manifold for the new motor.
Are the dual 38 or dual 44?

 

[mademan9]

Here is the description from ebay.


This is the more desirable dual carb motor found on RoundNose Yamaha Superjets, Waveblasters, WaveVentures, WaveRaiders, and more. This motor was just pulled from a great running superjet, and as you can see in my photos below, it has strong compression at approximately 160lbs per cylinder.



This motor was originally out of a WaveVenture so it has 62t Cases and 62t Cylinder, thus I am including the exhaust manifold bolts so that way you will have everything you need in case you are replacing a 61x motor (the 62t bolts use a larger/stronger thread on the exhaust bolts as opposed to the 61x.)



I went through the motor in August and installed a new top end with WSM Platinum Pistons/Bearings/Pins/Clips as well as new base and head gaskets. There are approximately 10hrs on the motor since the rebuild. It runs strong and it is ready to drop in almost any older Yamaha Ski. Upgrade that 650 or single carb 701 to a nice dual carb 62t!!!!


You will be getting the assembled shortblock plus bedplates, flywheel cover, engine coupler, and a starter motor. Electrical, stator, flywheel, carbs, etc.. are NOT included

 

[mademan9]

The carbs are dual 44's

 

[Matt_E]

So you will remove the stator and flywheel from your 650 and install it in the new motor.
I suggest you get yourself a 61X CDI with a higher rev limit (or one with the rev limit removed, or an MSD Enhancer). This isn't strictly required, but you won't get as much out of the motor as you can.
You will need an intake manifold and reed blocks - can't use your 650 stuff there.
Your exhaust may or may not fit.
The 650 exhaust manifold might not line up properly with the port and water passages on the 62T cylinder. Try it out I guess. If it does line up, you can drill out the bolt holes in the manifold to fit the larger bolts through it.

Does your current pipe bolt to the head? If it does, you'll run into a problem with the 62T head, as the bolt locations for the pipe mount are different.

 

[mademan9]

Ok i got it. i have been looking around on the x and other sites like blowsion. I found a couple things. Blowsion makes a few cdi parts but dont know which one is the right one. And you said i need reed box, jetsport484 is posting that he has a 97 Stock intake with reeds. Reeds look good, all close fine, nice seal. Parts came out of 97 superjet. would that work

 

[Matt_E]

No, it would not work with your dual 44 carburetors.
The reeds would work, but not the manifold.

 

[mademan9]

Where is a good place to look for manifold? And what exactly do I need ? intake manifold for dual 44 carb, right? Sorry for some many questions, just dont want to screw up a good motor

 

[mademan9]

Hardcore posted that he has a dual carb intake manifold for a stock 62t... How does that sound?

 

[Matt_E]

You need a manifold for dual 44 carbs.

Here are some reeds
Here are some CDI's
Here is an Enhancer
Manifold + reeds This one should work with your carbs.
Bunch of intake manifolds

 

[Matt_E]

Hardcore posted that he has a dual carb intake manifold for a stock 62t... How does that sound?

A stock 62T intake is for dual 38 carbs. Unless I am grossly mistaken, that will not work for your dual 44's.