need some help guys

[pythonz281]

I have a 1996 gtx 787 i have spark to both plugs and wont fire even on either i know shouldnt use but i am running out of ideas i can pull the spark plug near the back of motor and sounds like its trying to start on the one plug but when i put it back in nothing what in the worlds would cause this
ps ...was ridding at full speed and motor bogged all the way down then stalled hasent started since

Thanks kenny

 

[kustomkarl]

What is your compression in the engine. It should be 150 psi ideally. If its low, say less than 90, it won't fire either with all the spark in the world.
Does it back fire at all? It's possible that the woodroff key that holders the flywheel on broke and it isn't in time. It will spark but not at the correct time to fire. Pull the cover and give it a look see.
Also check to be sure all the wires have a good ground and connection at the positive ends as well.

Karl

 

[pythonz281]

ok this is what i got

With one plug in and throttle colsed back cylinder 0 psi and front 110 psi think its time for a rebuild ,,,, if so is it safe to do a top end rebuild or should i just rebuild the hole thing

Kenny

 

[timmyboy76]

you plan on keep'n them for a while?

 

[kustomkarl]

Well, you could start by pulling the engine and tearing the top end down. See what it looks like. You might want to join as a "premium Member" so you can down load a seadoo manual from our library. You can either read it on line or print it off and keep the copy for your own personal and private use. If you get in a jam we will be here for you to point you in the right direction. Click on the Manual link for more details. We also have a sister company that sells seadoo parts at a very fair price. Click on the parts link at the top of the page or in my avatar.

Keep us posted on your progress. Remember were only a click away.

Karl

 

[pythonz281]

thanks guys

I do plan on keeping the skis considering i brught them both running for 1500 with trailier ......

Update i pulled the motor and took top end off dont look to bad but i really would like to get some pics up here so u guys can see them and tell me witch way to go but i dont know how to post them ... i also was wondering it i should just do a upper rebuild or rebuild the hole thing ... as for becoming a premium member i dont have a pay pall account and dont want one if u guys have another way then i deff will become one ... thanks agian for all your help

http://s578.photobucket.com/albums/ss221/pythonz281/

Kenny

 

[b15philly]

I would upload your photos to photobucket.com. Then copy the bottom link below each of your photos and paste it in the text box here:cheers:

 

[pythonz281]

Here is the link to my photos

let me know if it works

Kenny http://s578.photobucket.com/albums/ss221/pythonz281/

 

[timmyboy76]

topend..

bore it out, get new pistons and gaskets.
http://cgi.ebay.com/ebaymotors/SEAD...00295440911QQptZPersonalQ5fWatercraftQ5fParts
probably, cut you deal for 2, and i have gaset kit if interested.

 

[kustomkarl]

The only was to get a premium membership is sign up for pay pal for free. Than subscribe...or go to a seadoo dealer and get a manual for $85.00, like I did before the forum had one in stock for $10.95

Karl

 

[pythonz281]

i have to bore first

bore it out, get new pistons and gaskets.
http://cgi.ebay.com/ebaymotors/SEAD...00295440911QQptZPersonalQ5fWatercraftQ5fParts
probably, cut you deal for 2, and i have gaset kit if interested.

i am def interested let me get the bore done so i can see what size pistons i need first

thanks kenny

 

[PWCdoc]

Python, the machine shop will need the pistons first in order to bore and hone the jugs. Pistons can vary slightly in size and therefore the machine shop will actually measure the piston and machine the bore to the proper specs (that you supply) to accommodate the supplied piston. The pistons are stamped with a number on top of them to let you know what bore size they are so you order the correct pistons for the next oversize.

In the photos you supplied...the picture of the exhaust appears to have had water sitting in it for quite some time and you ask "is this normal" in the caption. The answer is yes and no....yes it's normal if you've flooded it and never blew the water out of the exhaust afterwards...and No it's not normal if you take care of your stuff. Given this...keep that boat taken care of after you get it cleaned and repaired.

On the pistons....the rear appears to have leaned out, gotten hot and melted the edge of the piston. This can be a common problem on Doos on the rear cylinder. You will need to rebuild the carbs to make sure you don't have another failure. Also, you might want to consider replacing the fuel pump on the front carb, that supplies fuel to the rear carb after the front carb gets its fuel, with a dual output Mikuni fuel pump that will supply equal pressure to both carbs at the same time regardless of carb condition. When the diaphragms inside the fuel pump begin to age, they start to lose their efficiency and gradually begin to flow less fuel. In the grand scheme of things this is ok but when the diaphragms are near the end of their life they will only flow enough fuel for one carb/cylinder. The fuel pumps are very easy to install and a bracket is made to mount the pump on the front of the motor next to the carbs.

So, in my opinion, this is what you will need to do a quality rebuild:

2 pistons. Go with Pro-X
Top end bearings
2 carburetor rebuild kits
1 Mikuni fuel pump, mounting bracket and some fuel line
Associated gaskets
Machine shop services
Some grease (for o-rings) and sealants (for gaskets)

 

[pythonz281]

Thanks pw doc

I have tried very hard to take care of them since i have owned them they were sitting for almost 2 years since i got them and the last owner omg did nothing ..lol ..

This fuel pump u are talking about am i adding another one or replacing the one i have .. and how much oil should it use with a full tank of gas.. and i think i am going to premix what do u guys think whoul this help the problem so this dont happen agian .. thanks kenny

 

[timmyboy76]

I have tried very hard to take care of them since i have owned them they were sitting for almost 2 years since i got them and the last owner omg did nothing ..lol ..

This fuel pump u are talking about am i adding another one or replacing the one i have .. and how much oil should it use with a full tank of gas.. and i think i am going to premix what do u guys think whoul this help the problem so this dont happen agian .. thanks kenny

cant blame the oil injection anymore. i'd mix 16oz of oil, to every 5gal of gas (40/1 mix)
Think what Doc is referr'n to, is an external fuel pump(65 buks) and it cmes w/ block-off plate and gasket for the removal of pump that on the believe "mag' carb.
#53....http://partsfinder.onlinemicrofiche.com/seadooforums/Seadoo_oem/Seadoo_PWC.asp?Type=13&A=43&B=17

 

[pythonz281]

cant blame the oil injection anymore. i'd mix 16oz of oil, to every 5gal of gas (40/1 mix)
Think what Doc is referr'n to, is an external fuel pump(65 buks) and it cmes w/ block-off plate and gasket for the removal of pump that on the believe "mag' carb.
#53....http://partsfinder.onlinemicrofiche.com/seadooforums/Seadoo_oem/Seadoo_PWC.asp?Type=13&A=43&B=17

thanks timmy ...

i guess premix is the way to go now LOL

Kenny