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95 spx 657x electronics on a 96 gti 717 ???

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jbug

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hello..my first post here...im sean..i have a 96 gti with a good motor,no dess keyfob, the grey box was submerged for a while, looks like crap, i have a 95 spx for parts .clean electrics, can i use the 1995 657x harness, flywheel, stator on the 1996 gti 717, and eliminate dess?? what would it take? thank you.
 
The 657x mpem has a lower rev limiter than the 718, if you want to get rid of dess you'd want a 718 mpem from a 95 xp
 
mpem

by mpem are you refferring to just the epoxy filled device with wires coming out of it inside the gray box, or the whole gray box? and do i loose the info center? thanks for the reply
 
mpem

also, if im understanding you, i could run the 657x mpem for now, and would be slightly down on power? is it true the 657x has a more aggressive spark curve? possibly giving better midrange? sorry for all the ??? this is my first ski project in a while
 
What Strizzo said is true but it could be overcome with the addition of an aftermarket rev-limiter. Yes the X electronics have a better spark. Notice the 5 wires coming out of the mag area instead of 4.
 
also, if im understanding you, i could run the 657x mpem for now, and would be slightly down on power? is it true the 657x has a more aggressive spark curve? possibly giving better midrange? sorry for all the ??? this is my first ski project in a while

What is the pn on the back of the mpem?
I'm no expert but I read a post where the 657X is comparable to the 717.

Its the 657 that is not.

Heres is a quote from bills86e

"In 1994 the XP had a 657X motor with a 278000071 mpem.
Kindly look in your electrical grey box for the big module with about 13 wires or
so, and look on the back for the part no.
In 1995 the XP went to 717 (and 787) 717XP engine with a 278000423 mpem,
that also that mpem was used on the GTX 657X engine. Same flywheels &
stators, so that kind of leaves us to conclude the two mpems timing curve
ROM is the same on the 717 engines as 657X. Carb Jetting IS different.
Suggest you open mag cover, pull flywheel and see if Stator timing marks
at 9:30 o'clock are aligned and woodruff alignment key is intact, clean by
vaccuming, and close back up. I agree with SeadooSnipe that the Rotary Valve
needs re-checked for its timing position, and that the 717 needs a 159* valve
properly positioned on the RV gear useing a degree wheel and the mag cylinder
at TDC.

From link
http://www.seadooforum.com/archive/index.php/t-24354.html
 
Ok now that Ive messed with these machines...you cant just say b/c its an X motor, it has different electronics. ALSO...the rev limit.

The 95 they changed the rev limit on the MPEM of the 657s....and the X motor had the regular ignition. In other words...the 95 machines except the 580s (and the xp800) all had the same MPEM.

The 93 and 94 XP are the ONLY 657x with the 5 wire stator.

SO....it will be plug and play with the exception of the gauges and VTS wiring...you'll prob have to do a little work there but it will otherwise be plug and play.
 
sweet

thank you so much for all the info!! you guys kick ass!
the 95spx has the xxxxx423 mpem so i lucked out with that, awesome
im not using the trim on the gti so im ok there, so it sounds like just need to figure out the gauges and im good to go?
the gti carbs were submerged for a while too and the spx carbs are clean so i was going to use them also, should i just swap in the jets from the 720 carbs
? could any of you point me to a wiring harness diagram for a 95 spx and 96 gti?
thanks again, i really appreciate it
 
thank you so much for all the info!! you guys kick ass!
the 95spx has the xxxxx423 mpem so i lucked out with that, awesome
im not using the trim on the gti so im ok there, so it sounds like just need to figure out the gauges and im good to go?
the gti carbs were submerged for a while too and the spx carbs are clean so i was going to use them also, should i just swap in the jets from the 720 carbs
? could any of you point me to a wiring harness diagram for a 95 spx and 96 gti?
thanks again, i really appreciate it

I have one easier.
I went from the two to one carb on both my 96 GTI's.
For what your going to pay for 2nd carb rebuild kit source a single carb intake for and use a bigger main jet.

Heres a good link for gauges and schematics

http://www.seadoosource.com/gaugeinfo.html
 
what would be the advantage to that ocod? i would gain simplicity and mpg, but i would lose power, wouldnt i?
 
If youre carbs were submerged are you sure water didnt get into the engine. Just wondering, from what youve described it seems as though you had alot of water in that hull for a while.
 
hmmm.. i havent torn it down to check, is there another way to check without a teardown? it had 160# compression and i didnt see any water fly out, it would be nice to know, ive been toying with the idea of tearing it down since its sitting on my bench, what would i need as far as gaskets?
 
I was wrong earlier in this thread. I see now that my point only works on the 94's(and old yellow engine electronics). Good thing Minne was able to clarify.:blush:
 
Its taken me many years of screwing with these things to regurgitate all this nonsense. I thought the same as you Matt...up until a few years ago and making a mistake on a flywheel.
 
Well you could just pop off the head and look at the cylinder walls to see if there is any rust there and maybe go from there. That way if you just pop off the head you wont have to order any gaskets if the walls look good. Be carefull when taking off the head not to let any water or antifreeze to go down the jugs.
 
i popped the head off and other than a little corrosion where the rings were sitting at one point (that i couldnt feel with my finger tips) it looked ok, turned over smoothly etc.. my first instinct is to rebuild it, but moneys tight, and it did have 160 both sides, so im gonna run it
 
Another question, how do you know the electronics are no good? I know you dont have a key but if you hook up a battery and press the start button 5 times and you a beep and gauges kick on, then all you have to do is buy a key and have a dealer program the key or send it to minnetonka and he can program a key and maybe check out the box for you
 
well i dont know for sure, but i dumped about 12 ounces of rusty water out of it and it looks like crap in the box, the spx stuff looks to be in great shape and i would be eliminating the dess, i want this ski to be dependable, and i dont want corroded wires shorting out, the parts could be good still, but since i bought it as a basket case, already partially disasembled, i want to put it back together as clean as possible
 
Well that sums up my? I must get super lucky, ive never came across one with a box that messed up. The factory seal must be great, i think the only way they would get like that is if someone was messing around in there and didnt seal it back up correctly or it sat on the ocean floor for a while. We just picked up a 96 xp and 98 spx yesterday, they had seen better days for sure but the electrical boxes were mint
 
Just start plugging it in...there will only be a few connectors for the hood and VTS that wont match up. Colors should match up.
 
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