Kawasaki SeaDoo Conversion

[barefootpolaris]

So heres what I got. I have an older model (probably 80's model) js hull. Fully modified with custom paint and set up for a racing motor.

Was thinking about dropping in a seadoo motor, maybe a 720.

What do you guys think? Anyone have any inof of anyone else that has done the same?

Thanks guys!

BarefootPolaris

 

[SUPERJET-113]

There are conversion kits/bedplates to put a 750 Kawi in there. Why do you want a doo engine?

 

[madscientist]

720 has more power even in stock form

it may not go, the 720 just fits in a sx or x2 hull w/ little to spare

 

[Flat Brapp]

a 587 is a nearly dirrect bolt in.

 

[jeepmark4x4]

they do make awesome power for the cc but man do they weigh a ton.

 

[barefootpolaris]

Thanks guys for the info. Keep it coming. As for the first question, I can get a seadoo motor pretty easily, but I have yet to locate a good used 750 Kawi motor. If anyone has any ideas of where I can start scoring parts for a kawi 750 for cheap, let me know.

As for the 720/587 conversion, do you think the 587 would provide more power than the kawi 550 motor?

Also, does anyone have any further info on the 587 and the steps/modifications it would take to do this conversion?

Thanks guys!

BarefootPolaris

 

[Flat Brapp]

A 587 makes more linear power than a 550. I modded a 550 engine plate to accept the 587, somewhat simple, just measure... allot. The only real problem is the exhaust is on the opposite side as the 550, i ran a jetcraft silencer and ran the exhaust out the back left side.

 

[WFO Speedracer]

The 587 is not worth the effort,the 720 and 587 are virtually identical in physical size but the 720 is the only way to go if you want any real power.

 

[barefootpolaris]

The exhaust issue may actually work out better for me. I forgot to mention when I was refering to this 550 hull that the exhaust port had been moved to the right side of the ski instead of it being in the stock left hand side location. The previous wrencher moved the exhaust port and placed it below the water line. Kinda makes me think this hull may have already seen a conversion at one point!

Anyways, I love the idea of using the 587. I dont know much about this motor but the whole idea behind this project was to make myself a new challenge.

Flat, do you have any pics of that conversion? I have an two extra engine plates, so I guess I can use the trial and error method for this one :biggrin:

BarefootPolaris

 

[barefootpolaris]

If the 720 is identical in size, does this also mean that it will be a near direct bolt in?

 

[brett]

put a 6m6 motor in it. it'll be more reliable than stock

 

[barefootpolaris]

brett, this may be dumb but what is a 6m6 motor?

 

[brett]

650 yamaha engine. cheap and lots of parts for it

 

[barefootpolaris]

hmm, so many options. How much do you think a good 650 motor with all the electrics will run?

Think it would be hard to modify the motor mount plate for?

 

[WFO Speedracer]

I would say the doo would be easier conversion wise that the yami engine.

 

[brett]

hmm, so many options. How much do you think a good 650 motor with all the electrics will run?

Think it would be hard to modify the motor mount plate for?

i just sold a block for for 250, you should be able to find a complete 650 for under 350 bucks.

I would say the doo would be easier conversion wise that the yami engine.

but a yami will be reliable and actually worth something if he parts it out later okey:

 

[WFO Speedracer]

i just sold a block for for 250, you should be able to find a complete 650 for under 350 bucks.



but a yami will be reliable and actually worth something if he parts it out later okey:

I guess it depends if you want a dependable motor thats a pig or a dependable motor that rips,the 6m6 is a pig.:moon:

 

[FreestyleFreak]

If your gonne go through all the work to put a 6m6 in it you mine as well put a 701 in.

 

[brett]

If your gonne go through all the work to put a 6m6 in it you mine as well put a 701 in.

good point.

reliable seapoo-lol
the 657 i had in my parents spx wasnt so reliable....

 

[WFO Speedracer]

657'S were pigs and unreliable ,thats why they only lasted two years,the 720 on the other hand has been around ever since,night and day difference between those two engines.