Rebuilding a XP 720 Motor

[bigJake]

Lou, On my GSX skis there are 2 black plastic vent hoses about 1 1/2" in diameter in the front compartment. I think that is what he was referring to when he said vents.
Guyph, I've never flipped a ski over, but I don't think that is how it might get alot of water inside. When skis get flooded, it is usually because of a leak. Some possible causes of water leaks include:
- plugs left out
- bailer lines not tied up and drawing water into the hull (as Lou mentioned)
- leaking carbon ring or bellows
- water line leak inside the hull

 

[Guyph_01]

yeah thats what i was talking about. the two black hose that cross in a x and go up to where the compartment hinges are.
Ok i'll install a bilge pump Guess it will help if i forget the flush plug again

 

[Guyph_01]

Hey Guys,

Well little update on the ski, Got ride of the home made carpet foot grip job and replaced it with a rubber/foam mat used normally for gym or yoga stuff I still have to glue it but first i want to paint the black area where the white paint from the hull is visible. What paint should i use? What do you think of the mat? I think the colour suits it. Just hope its gonna last
Next will be installing the bilge pump. How is this done, glued, screwed etc?
Thx

Before:

Somewhere in the middle:

After:

Now i also need to paint that rear holding bar, not sure, yellow again or the original purple? and again what paint should i use?

 

[seadoosnipe]

Wow, hard to believe that is yoga mat. Looks awesome. Let us know if you have any breakdown. My first impression is the mat may not hold up with continous water. Over a year or so, the material itself could become brittle from the sun. But, if it works out and lasts for a year or two, then it's worth it.

Right now, HydroTurf has sheets of their 2 tone red in close-out for $40 bucks. I only bought my GTX mats as a cut set, all my other turf products I bought by the sheet and cut, put on myself.

I'm not any good at painting, so I'll let someone else give the advice there....

 

[Guyph_01]

It was a $18 mat. Yeah i thought of that but i guess theres only one way to find out

 

[1MACGYVER]

The spray that Brendon would have put all over the engine is the BRP XPS spray, it stops corrosion and you can put it through the engine to fog it- i use it all the time.
Good idea to hose out the bilge as you will almost certainly be in salt water, just tip the trailer up as steep as you can and run the hose below the engine slowly.
You might find the yoga mats are a little slippery when wet, hydroturf is the way to go.
Next week ill meet you at the river and go for a blast

 

[LouDoo]

Paint, I've never painted a ski but a buddy (mate) of mine has. He used an automobile enamel, Dupont Imron, it's a high performance paint and if fairly expensive, but you won't need much, probably a quart. After the Imron he used an automotive clear coat. It looks great, I don't know what he did for preparing the surface, if your interested I'll find out. He's the manager or the body shop at the car dealership where I work, so he probably knows what he's doing.

Lou

 

[Guyph_01]

Hey guys, How important is the VTS is think its called and what is it useful for?
Had another great day today on the ski since 4pm till about 7pm on the river

 

[LouDoo]

The VTS (Variable Trim System) in a ski is not so important, in fact the one on my 96XP doesn't work. Generally the way you set it is at WOT adjust for maximum RPM. I'll bet it winds up somewhere near the middle. It sets the plane of the ski on the water, on an XP trim tabs work better.

Glad to hear you're having a good time on your ski, it's supposed to be in the mid to upper 50's here tomorrow, I'm thinking about going out for a ride myself.

Lou

 

[Minnetonka4me]

The best metal protector is film fluid...hands down. John deere uses it on all metal parts of tractors when exporting them and can be found at any John Deere dealer. It is also awesome for snow plows and snow throwers to keep snow from sticking.

You can get a free sample at filmfluid.com

On the VTS...its not all that important. Set it manually by taking the motor out and turning the knob by hand. set it so the nozzle is level or close to it.

If you do decide to fix it, I have many VTS housings, motors, covers, and seals in stock.

Nice job on the mats.

Can anyone think of the model that grab bar came off of...or is it painted? 95 720s came with purple grab bars...I cant think of any that had yellow ones...

EDIT....its painted...you can see it.

 

[Guyph_01]

Yeah its been painted.

I'll see if the VTS is fixable. What should i look for, What are the common Faults?
The mat has surprisingly been holding so far. Quite happy with it and doesn't slip that bad but when compared to the hydro turf on 1MACGYVER its much more slippery. I'll try and look for some hydro turf on ebay

Had another great 2-3hrs fun this time free-style with 1MACGYVER and his mate. His ski is scray fast and fun as its very Narrow and unstable. The best thing its the same engine as mine except with a few mods. Might look into some mods later with Minnetonka if he has anything
When i got the ski back from the shop the guy told me he didn't have the parts to rebuild the carby and only cleaned it and that it was leaking with the needle and seat:S and that he will look into it after new year. I've done 2 tanks of fuel now
After the fun day 2day on the last lap i turned and hit a small wave and fell off. Once back on the ski started but then it died after a minute heading back to the beach. 1MACGYVER towed me back to the beach. After changing spark plugs that were not the problem We got it running by squirting fuel over the carbies from the air filter and concluded that because my mate was running the ski in the end on reserve that dirt might have blocked the carby.

Got home and washed down the ski, Made a gravity feed bottle device to feed fuel in the carbies to flush the motor. Also tried to figure what was wrong when we got a revelation. Maybe the tank is empty...., hahahaha, it was!!!!! Got some fuel from the station and brummmm, it started

Lol I think this and forgetting the rear plug, i should post on that other "stupid thing you done" Post

Loving my JET SKI

 

[LouDoo]

You can get a 15% discount on Hydro Turf by ordering from PWCMuscle.com, see top of page. I think you'll find it's not a good idea to run your ski out of gas, not just because of the inconvenience but also your going to suck a lot of crap for the bottom of the tank into the carbs. I don't usually let mine get below 1/4 tank.

Lou

 

[Guyph_01]

Is it 84.99 - the 15%? Also should i get the diamond cut or the groove type? Its good that there is purple? what other colour could i get that would look good?

I'll keep that in mind. but i had no idea fuel was low:s Would a fuel filter be a good idea?
Also the fuel gauge doesn't work normally what brakes? hopefully i can used the spare parts from the explorer to fix it

they don't ship to australia. Would anyone want to ship it here if i buy it?
Also i've seen some one ebay for $119 posted. might be cheaper. Is it the proper stuff tho??


Happy New Year

 

[LouDoo]

On the Hydro Turf, I use the groove cut because it's supposed to last longer, I don't know if it's true or not. Also there's a competitive product called Black Tip, they might ship to Australia, I'll PM you with a couple of links.

An inline fuel filter is a good idea, just use an automotive type, an auto parts store usually has them on the counter, I use a Fram G-2, or G-12.

There's a fix for the fuel gauge problem but I have found that it's usually just the float, use the newer molded type.

Lou

 

[Minnetonka4me]

Its either the float or the pickup....on the older ones typically the magnet just falls off the float. Glue it back on and you are in biz.

Its not a fun job...but just take the lines off and get them out of the way. Then slide it up...the last inch is a beeotch so just take it slow, work it at an angle to get the clearance you need...and out she'll come.

I have many used ones for $50 if you need one. And sorry...no mods here! they go quick. On the 720s Most people agree it makes them extremely unreliable. I would recommend a good prop and intake grate (if you ride rough water and arent worried about top speed)

If you do anything...a bump in compression by having the head milled, cone filters, and a good rejet kit would be the most I'd do on a 720.

 

[Guyph_01]

Cool Cool, some good tips, thx guys. Well mods at the moment is wishful thinking. I 'll try and get it running good first them we will see.
I think it better for me to get the fuel gauge sensor etc working than the vts. 1MACGYVER has a manual adjustable one on his ski. Is that any good apart from the inconvenience of manually stetting it? and would it bolt on to my pump?

Also when we where cranking the engine when it didn't have fuel, I noticed that one lead was a mm close to a metal clap and was sparking. I moved it away and that stopped. Does this mean i need new leads?

I'll first try and get the sensor out of the explorer to get familiar with it and then try on the xp. Is there a way to test the float or the pickup to know if they are good? or buy sending pics would you be able to tell. Maybe i can swap the explorer stuff over if they are good and the same. Or should i just go with the newer ones like Lou suggested

Thx guys

 

[Minnetonka4me]

Not positive the fuel senders are the same length but its worth a try. Its a total PITA to get out though on the explorers...hell its even hard to reach in and test them!

 

[Guyph_01]

I got it out buy removing the top center console

This is what the black float off the explorer look like.

But after i cleaned the tank and pipe, i put it back in the explorer to try and see if i can get work. I think i'll just buy a new float as its relatively cheap and will last longer. Only thing, i'm able to get those special fuel clips off. Some get destroyed in the process. Can i just put normal claps back on?

Thx

 

[Minnetonka4me]

Dont use the old clamps anyways...they suck.

I use good Zipties, many perfer hose clamps. Just make sure they are 100% SS.

 

[Guyph_01]

Cool thx. Any ideas on how i can get it to work on the explorer on my other post?
thx

 

[Guyph_01]

Some pics of the river run we had a few days ago

Lol my girlfriend who is pulling me, got scared and raced back to shore when see saw the cop boat. They gave us a warning as we need to have a spotter on the jetski when pulling...

 

[LouDoo]

Good to see you out on the water having fun, I'm glad you only got a warning. The cop boat looks like a big brother to your Explorer. Now if we can get the Explorer back in the water you'll have a fleet. BTW it's 20 degrees F here today.

Lou

 

[1MACGYVER]

Those river cops are like ninjas, they appear when they smell fun

 

[Guyph_01]

Hey guys, Had another good day out 2day. The river was a bit rough because of the wind. The ski also felt like the prop was turning but not pushing enough water. What can be done to improve this? Also it happened when i tired to pull a tube, I'd hear the engine rev but no proportional go if you get what i mean. So i didn't insist to much.
thx

 

[1MACGYVER]

Look for an intake grate for it, Worx or similar. It will keep you hooked up far more on the choppy water which is so common here