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Rebuilding a XP 720 Motor

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Lol you guys with your oz. and lbs. We talk in Liters and Kg here:p
Not sure i'll go see the boat tomorrow. thx for the info.

Anyone else has advice, info, tips??:)

Thx
 
That thing still has oil in the tank and it looks like fuel also.Battery.
I'll give him a bell tomorrow and see what he can come up with.
 
very well spotted there. Yeah he is gonna find out more about it tomorrow. I'll ask and see how long it stayed under for.

Any other tips?
 
Hey Guyph
Ok.Spoke to the guy I know.A stage "2" rebuild(bolt your carbies, exhaust on,rebuilt crank,new rings,pistons bearings etc.virtually a sealed motor .About 2grand.Unless other parts come into play!)Being a motor that has no history to you,electrical will most likely be an issue
His recommodation is to NOT go ahead with the rebuild.It will cost you a lot more than the ski could ever be worth.
This is from someone that could make money from doing it.He is not knocking back the job, he is giving his advice to me as a mate.His words were a cheaper rebuild will come back to haunt you.Everything has to be done 100%.I told him about your trailer and he says you are sitting on $900 just there.Good used trailers are as rare as rocking horse shit and they can't get enough of them.
His thoughts are to get a ski that is running without any problems and/or maybe need a top end.It would be better to go that path than to dig up the dead.Sorry to be the bearer of news you probably did not want to hear.we both know what stuff costs compared to the US.
 
hey guys,

Ok well i went to have a look at that ski boat and engine is sized. Its a shame, apparently it sank, was recovered but then let for well close to a year now. Could have maybe been brought back to life quick after as it was apparently a good motor. Anyway. From all the parts that i need to buy, Head, pump, oil system, carby etc etc it looks like buying the boat come about the same price. Ok i know no one in the US would pay this much but its whats it gonna cost me if i had to ship parts or buy them second hand here.

Yes from local guys a total rebuilt is gonna cost me about $2000. And yes i could buy a good running similar ski for $3000 if im lucky or 4-5000. Which turns out to be what this one is gonna cost me with all this. At least that way i'll be sitting on reliability and peace of mind as long as i take good care of it which i will having spent that amount of money:)

Also i might be able to sell some of the good extra spare parts let over from that ski-boat.

Another thing that i've been thinking and tempted to do is to stick an out-board on the ski-boat but not sure if its gonna even be legal plus thats more $$$ to spend. Time will tell. So for now looks like this is my best option.


I would like to say a huge Thank you to all you guys that have posted on this thread. Thx for the inquiries you did and thx for your time going out of your way to try and help me. Its been much appreciated.

Will keep you boys posted on whats happening Down Under with my little ski:p
 
All it means is ok.If you need a hand to source any parts etc,pm me.With the boat,post a pic of the transom and I'll see if you can bolt an outboard on it easily.Legally should be no problem.Mate .We were all worried that you may have to spend money on unforeseen problems and that the project would cost you a lot of hard earned.Thats all:cheers:
 
Hey mate, Yes i thank you all for the advise and concern, but i'm gonna keep it as long as i can and it wa gonna cost me easy about $1000 to get the parts i needed from over east or US Plus A fresh rebuild engine is $2500 where as a running second hand one is around $2000 here.

So yeah overall i think its ok. I'll just have to sell my project bike, my 2nd car and a few other thing to get the money:P Lol my 2nd car, reliable daily runner, is worth just under whats its gonna cost to rebuilt the engine. Crazy....
 
Mate.When you get it on the water you will have a ball.Keep in contact here and tell us how you are going.Or stay and have a joke or two.all the best.
 
Yeah that shipping is insane!! Maybe check with SBT; I have heard some fairly good price quotes for international shipping. Then, I could send in this crusty motor in as a core. May just be cheaper than a local used motor!
 
Hey guys,

So the plan is to get the engine of the jet boat out and send all the parts and the ski to the mech that will help with the rebuild. Anyway i've started to remove the engine in the jet boat. I'm not at that stage yet but once i get all the bolt out, how do i get it out? I mean how do i get it off the shaft?

Any detailed steps or tricks i should do?

Thx
 
Hey Mate,

If you haven't already done it the first thing you need to do is download a manual, you can download one from this site if you join as a premium member, or just google it and download one elsewhere.

It's not that difficult to remove the engine, probably even easier in a boat than a PWC. To free the drive-shaft you'll need to pull the pump. This is good practice, this way you'll know how it goes back together. After you remove the pump, remove the drive shaft, disconnect the wiring, hoses, loosen and remove the four bolts on the motor mounts and remove the engine.

You can remove the engine with a hoist, or a block and tackle, get two old spark plugs, break off the insulators and weld a large washer one each plug, you can use these as lift points. It's easier than you think.

You'll need to talk with your re-builder to see how much he wants you to remove from the block, ie: carbs, exhaust manifold, starter, flywheel, etc.

Lou
 
Hey Guys,

So it looks like i'll be getting my ski back in about a weeks maybe two weeks time max. I wanted to ask with you guys experience what should i do and what not to do maintenance wise. I'm not to familiar with them and wanted to get as much info on tips etc to maintain it as long as possible.

Being a fully rebuilt engine, having experience with cars only, should i run special oil in it? when is the first service due? what needs to be replaced? when and at what interval are the regular service normally done? How to properly flush it and for how long? Have i missed anything else i should have asked?

Thx guys:)

P.s Little pic of the day i bought it:p
sdc19854.jpg
 
These instructions are from SBT, Small Block Technologies, the largest re-builder of SeaDoo and other engines.

Proper break-in of your engine is the most critical aspect for determining the longevity and performance of your engine. Engines not properly broken-in will often fail within the first minutes of operation. Ring failure and piston seizure are the most common symptoms of an improper break-in procedure.

During the first 10 gallons of gasoline, there should be NO full throttle operation. First idle the engine for about 10 minutes to ensure that the engine is properly warmed-up. Then begin varying the throttle position up and down, up to 20% throttle for a half hour. Then come back and let the engine cool off completely - it should be a good 30 min break. After it cools down, you may now ride it up to 50% throttle for another half hour or so. Then come back again and let it completely cool down again. Now you can go out and ride up to 90% throttle. Continue this for the remainder of the 10 gallons, never holding one throttle position for more than a few seconds. Do not run at a steady throttle position and do not go to 100% throttle. After your first tank of gas, replace your plugs with fresh ones. For the second tank, you may ride normally with one exception - do not hold it at 100% throttle for more than a few seconds. After the second tank of gas, you are completely broken in and may ride anyway you like.


The only thing I would add is, just to be on the safe side I would run for the first tank of gas premix, like about 50:1.

Lou
 
Lou that is too much; obviously you want to make sure the oil pump is working properly. If it is....100 to 1 on the premix.
 
Little update, Will be getting the jetski by the weekend if all goes well:p Wooouhouuuu:D

Little pic i was able to take at the shop this morning, new crank, pistons:)

20111221134928.jpg


20111221134939.jpg
 
Hey guys,

So ive been out a 4 times already on the jet ski. I'm now at 90% throttle and having a blast but still taking the breaking seriously. On the third out i forgot to secure the flush plug. Was bang in the middle of the river and suddenly realized so i zoomed back to the shore and pulled it up and plugged it lol. But yeah having a good time so far.

Little question, When washing down a flushing the ski. can i rinse the inside? also i noticed when i got the ski from the shop he had put a oily liquid all over, this now has dried. should i put it on again to prevent rust? what is it? and where should i not apply it?

Also found that the foot grips where replaced buy marine carpet and that the little securing holes for the only foot grip allowed water in the hull. So i ripped all the carpet off siliconed all the little holes and laid new foot grip material i got at a rubber shop:)

Any other advise guys?
Thx
 
Hi,

Glad to hear you got your ski running. I think we've all left the plug out of a ski or boat, I know I have.

It's a good idea to rinse out the hull after each use if you are using your ski in salt water. What I would recommend is a good cleaning each year, I use Castrol super clean, and just a light rinse each time you use it. You should also flush the engine each time if you're using your ski in salt water. While it's probably not necessary each time you could spray the engine down with silicone lube occasionally.

I personally think it's a good idea to plug the old rivet holes, I use 5 min. epoxy, but silicone should be fine also.

You have a real reliable engine, in my opinion the most reliable that SeaDoo ever used, just make sure you are using the correct oil, API-TC mineral oil, or synthetic blend (my choice). Do routine maintenance ie, change the pump oil and you should have good service for a long time.

"Rubber Shop", sounds kinky, I'm going to have to ask Cousin Criss about this. :rofl:

Lou
 
hehe, the shop is called Clark Rubber:) Its sell all sorts of rubber and plastic imaginable:p

Thx for the input:)
 
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Hey guys,

Having gone out a few times now i met a few other people with jetski's. most of them had new stuff like 07 and newer. They are a lot bigger and a lot more stable. For example if you set on mine it wants to flip but the new ones stay quite flat on the water.
Also i've been watching some you tube vids and specially the jumps etc, and stories on here how people go out and fall a few times etc.
My question is how much can i flip, fall, jump and get the ski under water?? I took the hose over it a few times and there doesn't seem to be leaks but im not sure. Only place i can see water getting in is when i open the front compartment and there are those two air vents i think.

Thx
 
I think what you are calling vents are actually self bailers, these should actually remove water. They work from a venturi in the pump. Usually if they are drawing water in it's because the hoses are not tied up high on the ski. I think I have a picture showing the proper position of the hoses.

You're right about the XP not being very stable, that's why they are so much fun to ride, and even though you can sit two on the ski I consider it strictly a one person ski. There's not another ski that can jump a wake like the XP. And yes you are probably going to flip this ski, just follow the proper procedure for righting the ski, and getting water if any out of the motor. If you don't have one already I would suggest you install a bilge pump. My 96XP already had a bilge pump installed, factory I think.

Lou
 

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