95 XP 717 REBUILD or NEW ENGINE

[PolarCelsius]

Welp, the ol' gal took a plunder, I would think it to be the grey tempo OEM fuel lines but could be something else. I hear a strange object being knocked around near the flywheel when turning the engine over

MAG cylinder 60psi
PTO cylinder 125psi (was 145)
Turns over just fine and even runs too

Crank has a very very slow shaft seal leak and oil fills the case over months of sitting (mitigated with ball valve) but I hear something in the flywheel housing when turning it over

Rebuild myself?

Send it off to Full Bore? Platinum engine w/ gaskets and shipping $1135 receive in late January

Send it off to SBT? Premium engine w/ gaskets and shipping $1245 receive in 2 weeks

 

[Pwnage1337]

Is it a 787 or 717?

 

[JeremyD615]

It really depends on whether you want to be back on the water this season. If so, SBT is your best option... You may be able to rebuild it yourself, but you won’t really know what you’re dealing with until you split the case...

 

[PolarCelsius]

Is it a 787 or 717?

717, my bad I forgot to mention that, I'll update the post

 

[PolarCelsius]

It really depends on whether you want to be back on the water this season. If so, SBT is your best option... You may be able to rebuild it yourself, but you won’t really know what you’re dealing with until you split the case...

I have another ski so I have my fix for the season, but the sooner the better, the crank should be fine besides the strange loose object within the flywheel housing, not sure what that is? It can't be apart of the crank because the crank turns over very smoothly and still runs, it's possible I could just do a top end after opening the flywheel housing and figuring out what that is

I also thought about doing a botch top end, just slapping some new rings on and hope it gets at least 120psi ( along with carb cleaning and fuel line replacement)

Yes I know that's not how we should do things but this ski has a first class ticket to being put up for sale instead of sinking more money into it since I'm selling it within a year anyways to make room for a Spark

 

[JeremyD615]

If that’s the case, go SBT... You’ll have a warranty on the motor, and won’t be stuck waiting on an engine when you’re getting ready to sell it next year. Since it’s already got leaking crank seals, I wouldn’t just throw a top end on it...

 

[DanSquires]

heads up, SBT is taking forever on 717's. I've been on backorder for a month for one, and still have another week to go.

Specifically for a 717 engine

 

[JeremyD615]

heads up, SBT is taking forever on 717's. I've been on backorder for a month for one, and still have another week to go.

Specifically for a 717 engine

Good to know! I guess those parts and labor shortages are getting to everyone... I had a motor ship from them right at the beginning of the whole pandemic, but I think it got out right before they started having to send people home.

 

[DanSquires]

Good to know! I guess those parts and labor shortages are getting to everyone... I had a motor ship from them right at the beginning of the whole pandemic, but I think it got out right before they started having to send people home.

I think it has a lot to do with the huge surge in used ski sales this year.. people having extra cash in their pockets and time on their hands to hit the water. Or people finally fixing that old POS that's been sitting behind the barn broken for the past 5 years.

 

[PolarCelsius]

UPDATE

Took the head off, found that the piston and cylinder are not in too rough of shape, a couple tiny knicks in the top and some very shallow and relatively smooth scoring on the wall



Think just a hone and some new rings will breath new life into her?

I also found the culprit, oil injection line going into the intake was severed in half, I pulled it off, I'll replace both sides of these

 

[PolarCelsius]

UPDATE #2

MAG piston is trash
PTO piston has visible scoring but very smooth

Both cylinder walls seem to be in alright condition, especially the PTO cylinder

I'm thinking just a basic pistons gaskets and rings kit with a hone will bring this engine back into play

Anyone think that a hone is not enough and I absolutely have to bore?

I know the crank seal leaked oil but it has not shown any signs of leaking since I got the engine running last year, so the bottom end could still be good

Just trying to not spend 1.3k on a ski hardly worth that much in total

 

[mikidymac]

Your cylinders are not ok. They have already seized. I would only suggest boring and a new top end with oversized pistons and a new crank. Otherwise you are going to be back here again. Also use the correct oil and check your fuel system.

 

[PolarCelsius]

Your cylinders are not ok. They have already seized. I would only suggest boring and a new top end with oversized pistons and a new crank. Otherwise you are going to be back here again. Also use the correct oil and check your fuel system.

I figured, I'm looking for a local shop that will bore and finish my jugs at a reasonable price, if not I'll probably send them over to Full Bore for 299$ +shipping but then play the waiting game

SBT's exchange is 475$ +shipping

I'm not sure if a new crank is totally necessary, I personally don't mind using the ball valve for the seal leak, and it's proven to be a very slow leak as I've left the valve open for weeks with no hydrolock

WSM Crankshaft is 445$ +shipping
how much more work would need to go into splitting the case and timing? Think its worth it or at that point just consider a manufactured from SBT for 1.2k$

I am also using the correct oil, AMSOIL INTERCEPTOR which is specifically recommended for Rotax engines, I use it on my GSX and MXZ sled
I will replace the grey fuel lines while i have better access inside the hull, and clean out the carbs, rebuild depending on green goo factor

 

[PolarCelsius]

BONUS QUESTION:


The pistons say 0.50mm on the crowns
Does this mean these are 0.50mm oversized already? (PO didn't tell me squat)

 

[mikidymac]

Do not send anything to fullbore as he is no longer reliable or recommend.
Yes your pistons are already 0.50mm oversized.

I would call Group K and see what his timeframe is. He is $110 to bore both cylinders and is one of the best 2-stroke machinists there is.

Also make sure your using API-TC oil only.

 

[PolarCelsius]

I decided to exchange my engine for a full rebuilt engine for a good price (750$)

He's a semi local independent BRP mechanic about 2.5 hours south of me
This man truly knows these engines inside and out in every aspect and has decades of hands on deep experience

Something he mentioned that I will have to say will be a very hard to swallow pill for almost every user on this forum due to the popular trickle down belief-

The grey tempo fuel lines do not degrade within their inner diameter and do not cause the well known green goo... The grey fuel lines are perfectly fine rather the true culprit are the brass fittings on the carb and petcock. He explained it as basic science and this radical notion of the fuel lines themselves causing the goo is simply impossible

It's called verdigris, it's cupric chloride, an oxidation of copper within the brass, it can take 20 years to begin oxidizing, hence why people blame the fuel lines they never changed, and swear that the new lines fixed the issue... Just clean/rebuild your carbs, and clean the brass fittings with baking soda and vinegar.
I'm sure many of you may disagree for what ever reason, but this man posses an undeniably vast amount of knowledge from hands on experience with 2 stroke engines and mechanical design in general.

That aside, I'll be installing the new engine soon, a success post soon to follow


Here is my multicolored rebuilt engine, which I think is just plain awesome (he offered me a full white engine as well, I chose this)

 

[Seadoo timebomb]

Please go thru and change all of your grey lines and selector valve.

I am glad you chose to do a complete engine swap. Your crank would not have lasted very long otherwise. It would be a waste to reuse that crank with the oil seals leaking between cylinders. But since the oil line took a dump and pistons seized, the lower rod bearings are usually the next to go.

Just like your oil lines the grey lines degrade over time. Same urethane inside the grey jacket. I was one of those hard headed people that couldnt swallow this at first. All of my skis were ridden nearly year round. The off season was usually 2 months at most for years. I let a couple of skis sit and then discovered the fuel lines had taken a dump. The urethane breaks down from saturation of old gas sitting in the lines. It is a combination of fuel going sour and fuel lines deteriorating together. I split many fuel lines apart to confirm this myself.

The other skis I ran never had the problems for many years later. When I slowed down riding as much all of them went south. The fine brown/grey grit you find in the water strainer is a mix of fuel line, selector valve metal, and old gas.

The green goo is common on anything with brass fittings. Even water pipes in your home. Just like old brass stuff turns green is same thing.

 

[mikidymac]

Ask your mechanic why seadoo, yamaha, Polaris, tigershark and kawasaki all use the same carbs with the same brass fittings fittings and only seadoo has the issue with the green goo? Oh, wait, Seadoo is the only one to use the gray Tempo fuel lines.

You can see in this cutaway, it isn't just at the brass fitting that these hoses degrade over time.

To be fair any fuel lines that are over 20 years old should be replaced since all of them degrade over time and it isn't worth losing and engine over an air leak in the fuel lines or an injury from a fuel leak explosion.

 

[Seadoo timebomb]

That cutaway came from return line connected to hose barb on rear carb. The green side was on the carb.


I find the green on anything with brass hose barbs. Outboards, tractors, old Cushman scooters. Even some cheap pocket watches. Just not so much the goo. But anything with grey tempo lines is a given. The Grey Tempo lines have been in use of outboards for 60 years. Before the introduction of mtbe and alcohol in fuel, there wasnt an issue.

 

[PolarCelsius]

You are right that every fuel line sucks
I replaced all the grey lines on my carb, have not gotten around to replacing all the lines on my tank and petcock yet
The grey lines on both of my skis do not look even close to being that atrocious on the inside, and both run very well

UPDATE: The new engine works great, I began the first step of the break in procedure, for those of you that are curious on how to treat a fresh rebuild-

put 3/4quart of injection oil into a full tank of gas
stay under 3/4ths throttle for entire tank of gas
second tank doesnt need added oil but dont WOT for more than 10-15 seconds at a time
third tank take it easy

these were the instructions provided by my mechanic, others may have a different procedure but this is how he wanted me to treat his rebuild

 

[SteveontheLake]

Just my 2 cents, I used Tom at SeadooEngineShop and he was a stand up guy and honored his word. $800 including shipping (back) for my 787 full rebuild. It did take a little longer than expected, but the country was under quarantine so it was expected.

 

[mikidymac]

Just my 2 cents, I used Tom at SeadooEngineShop and he was a stand up guy and honored his word. $800 including shipping (back) for my 787 full rebuild. It did take a little longer than expected, but the country was under quarantine so it was expected.

He might do good work and be a good guy but the experience on this forum has been ridiculously long wait times like months to over a year.

 

[SteveontheLake]

Yeah I saw some of those but they were old and we had a bad experience with Full Bore just getting them to talk to us so I chose him. Maybe he's gotten things together and maybe I was just lucky. Either way, I'm happy with the build.