650 to 701 swap

[B-Roy]

Hello,

Ive never done a yamaha swap, it's always been Kawi's.

What is required to drop a 701 in a 650 sj hull?:woot:

Thanks, Brian

 

[demolition_x]

nothing really. every thing should line up. i think the cdi is the only thing you might want to switch. 650's redline a little lower. but not a big deal if you mod it.

 

[DaUpJetSkier]

you also have to clearence the top case to allow for the bigger sleeves and pistons.

 

[B-Roy]

specs?

 

[demolition_x]

do you have a 701 motor?

or are you rebuilding a 650 motor with 701 topend?

if you already have a 61x or 62t motor you don't have to do a thing.

if you are using a 6m6 case and using 61x or 62t cylinders then you have to machine the bottom to fit.

 

[B-Roy]

Alrighty, Thanks for the info.

 

[meatball]

dont use 6m6 cases and 61X or 62T cylinders, its a shame because the case on the 6m6 is tiny and choked.

You can either drop in a complete 701 engine (exhaust, intake, shortblock) and use all your electronics (stator/flywheel/bendix/starter) except the CDI.

650 CDI limits at 6400 RPM
701 CDI limits at 7100 RPM

You'll want to swap it out

OR you can use the 650 crank and buy the cases cylinder exhaust etc. You CAN reuse the 44mm carb from the 650 if you get a 61X engine. I'd sell the 650 engine complete however, as nobody wants them. You'd probably even have to pay shipping to get rid of the stock 650 exhaust.

Dont use the 650 exhaust, it will bolt up, however its smaller then the 701 and will choke the engine.

 

[DaUpJetSkier]

OR you can use the 650 crank and buy the cases cylinder exhaust etc. You CAN reuse the 44mm carb from the 650 if you get a 61X engine. I'd sell the 650 engine complete however, as nobody wants them. You'd probably even have to pay shipping to get rid of the stock 650 exhaust.

thats exactly what I am doing right nowc ^ ^ ^ Now am I better off getting an msd enhancer or can I find a cheap 701 cdi cheap?

 

[sflsurfrider]

its not HORRIBLE to use 6m6 cases. i had 6m6 cases with a ported 61x cyl and it hit pretty nicely. it wasnt as strong as my 62t cases, but....

 

[jetskiking]

There may also be a difference in the exhuast manifold bolt size. Nothing a drill cant fix.

 

[sjetrider]

6m6 cases will choce a 701 cyl. no sense in spending the money on 6m6 cases, 61x cases are cheap.

 

[sflsurfrider]

no money needs to be spent on 6m6 cases if he already has them and a dremel.

 

[meatball]

DaUpJetSkier-

I dont know, I've used nothing but stock ignitions, but unless you find a cheap used MSD, I'd go with a used stock, the new MSD's are outrageous.

 

[Fathom]

I'm dropping a 61X motor into a '90 SN and the stock exhaust is so small. What is the normal approach to allow the exhaust to flow with the 701 and a B pipe? I've considered the front exhaust but I'd like to hear what most people do in this situation.

 

[The other Alex]

OR you can use the 650 crank and buy the cases cylinder exhaust etc. You CAN reuse the 44mm carb from the 650 if you get a 61X engine. I'd sell the 650 engine complete however, as nobody wants them. You'd probably even have to pay shipping to get rid of the stock 650 exhaust.

thats exactly what I am doing right nowc ^ ^ ^ Now am I better off getting an msd enhancer or can I find a cheap 701 cdi cheap?

Ive got a 61X CDI if you want it, I can send it up with the cash. Let me know