1996 GSX Build

[mikidymac]

Depending on shipping the OEM ones from Seadoo are actually cheaper. In California when you add shipping SBT is more for me than SBT.

 

[Jetjon24]

Where do you find oem crankshafts? I searched seadoopartshouse.com and seadoowarehouse.com and neither seem to carry a full crankshaft assembly. They have it listed, but with no price or anything.

 

[mikidymac]

Must be fairly recent but you are correct, no longer available. Sad day my Seadoo friends.

 

[Jetjon24]

Here are some pictures of what the crankshaft looks like. Honestly It isn't at all as bad as I expected, however some of the bearings are slow and crusty, and there was a lot more rust than what the pictures show. It is tempting to try to reuse it, but even I know better than that. Right now everything is fully disassembled, organized, and oiled up so it doesn't rust. Now I am just going to work on prepping the motor for paint while I try to find the money to get a new crankshaft. After that, I need to re-assemble the motor, clean the carbs, and then work on painting and cosmetic work for the hull and jet pump (which is fine, but all the paint is flaked off). This is probably where the process takes an abrupt stop and I won't be able to do much for the next while, but i'll try to post as I go.

.

 

[GGuillot]

Now I am just going to work on prepping the motor for paint while I try to find the money to get a new crankshaft. After that, I need to re-assemble the motor, clean the carbs, and then work on painting and cosmetic work for the hull and jet pump (which is fine, but all the paint is flaked off).

Don't overlook the balance shaft, you don't want this to fail, if it does it'll reek havoc on your newly replaced crankshaft and at worse crack the cases. On my GTX, I did a SBT core swap, on the GSX I did a bearing swap on the weight end. The weight end is typically where it fails. Any hint of the bearings not being smooth on the balance shaft I'd replace accordingly, if you're staying within a budget and the seals look good, just do the individual bearing changes. I think I paid $9 for a NOS Nachi bearing on the GSX.

If you do a crankshaft core swap or buy a new WSM crank, you'll need to get that PTO flywheel off or buy another used one. Be ready, it needs a shit ton of leverage to remove.

 

[Jetjon24]

I'm planning on pulling the PTO flywheel. I just need to go buy or borrow a chain wrench. That's an interesting point about the balance shaft. TBH I have never dug this deep into an engine and I have no experience working on cranks and balance shafts. While inspecting and wiping the rust of the crank, a small spring ring thing popped out of the mag side internal seal... Here's a pic of what I'm talking about

I take this to mean, "stop messing around with this crap and buy a new one so you don't blow up your engine" or blow $30 in oil and all the time it took to strip down the engine the first time.
So, as of now my plan is to save money and then get a full new crankshaft, because at this point I'm willing to spend money to do it the right way the first time (so that there is no second time).

As for the balance shaft, the PTO side bearing, which is open on one side, seems to be just fine and spins freely like a skateboard wheel. The mag side bearing however is slower and doesn't continuously spin, but it looks extremely clean and doesn't feel crusty. Is it supposed to 'spin like a skateboard wheel' too? or is it supposed to be a little stiffer? The other thing I'm not too sure about on the balance shaft is these pesky black ring/seals/whatever they are. They seem out of place. What is the purpose of these things do I need to replace them if they're opened up on the side and whatnot (I know it's a stupid question, thanks for helping me anyways)?

One last off topic question... I know you said hydroturf has great black Friday sales, does anyone know if SBT will have the same? I would be willing to wait an extra month or so if I could get 15+% off of a seat cover, mats, and especially a $300 crankshaft. Thanks for all the help!

 

[GGuillot]

The bearings should have no noise at all when you spin them, completely smooth and quiet. From what I can tell in the pic the balance shaft seals look fine. Your call, if both bearings are noisy or questionable it may be more feasible to do an entire balance shaft swap on it. It's a fight getting those bearings off, you'll need a decent puller to do it. SBT does have a core swap available, same process as doing the crankshaft. I'm not sure if the balance shaft is available anymore as a new OEM.

The black friday sale usually applies to Black Tip and Hydroturf products, typically at least 20 - 25% off, though it can vary each year. I've bought from PWC muscle, they're a sponsor for the forum, so you can always get a 15% off or free shipping usually through them when buying Hydroturf. Code is or was HYDRO15 at ck out. I haven't seen any other discounts on reman cranks or anything.

 

[Jetjon24]

It’s been a while since I’ve posted, so here’s an update...

I am still waiting to buy a new crankshaft so the engine is in pieces, but while it’s been apart over been doing some cleaning. The most significant thing is that there was a noticeable amount of carbon/rust on the top of the cylinder walls. In order to combat this, I tried some rustoleum rust dissolved, and it worked amazingly! Here are some pictures of before...


And here’s what it looked like after...



It worked well for me. I doubt it will lower compression or anything because it was not abrasive and I was gentle, I also didn’t leave it on for too long and applied multiple times (no more than 30min at a time), but I guess I’ll find out when I put it back together. If anything, at least I’ll know it looks good inside until I throw a rod

Thanks for the help. Hopefully I can get this project moving forward soon.

 

[Jetjon24]

I recently got my crank and gaskets in. When reassembling the engine I lost some parts so I just had to reorder them. I somehow lost my woodruff key and counterbalance shaft cap. I decided to order a gasket kit off eBay for $60 that came with every seal and gasket for the engine which was pretty nifty. I plan on buying a new hull soon so I can get started on the cosmetic part of things. Here are some pictures.

 

[mikidymac]

Make sure you pressure test the engine once it’s back together. Some of those Chinese gasket sets are questionable at best.
8psi for at least 10 minutes.

 

[Jetjon24]

That's a good idea. I hadn't considered that.
I have a question that seems like a stupid one, but I'm still curious to hear what the experts say... So after putting my engine together, I noticed it was kinda hard to turn by hand. It does spin smooth and freely without any clanking or anything, it just needs a good bit of force to move it. Without sparkplugs in, I can grab the PTO wheel with one hand and spin it but it is kinda hard to do. After putting the sparkplugs in, its really hard to turn, even with a wrench, and it seems to turn in stages (as pressure is released). I'm pretty sure this is all good and normal, but my friend has a 717 he just rebuilt, and you can spin that engine with your pinky finger. so the question... Is it ok that it is hard to turn by hand and then is really hard to turn when under compresson? I would think it's a good thing, but being that this is the first time I've ever touched the bottom end of a ski, I want to make sure nothing is out of whack before I press on with the build. Thanks

 

[etemplet]

shouldn't be hard to turn. Loosen the rotary valve cover and check it. Then.... loosen the mag cover. You have have a rub on the stator which might fit your description of how it rubs, in what you call stages. . The engine is not in the ski correct? Could be a bent counterbalance shaft but your description doesn't exactly fit. Good Luck !

 

[mikidymac]

It really depends on how hard it is to turn over and everyone will be different. A fresh rebuilt engine is not just going to spin over with a pinky and it will not free spin even with the plugs out but it should turn over smoothly by hand.
Your friend's shouldn't turn with a pinky either. You have fresh rings on the cylinder walls, fresh seals on the crank and the 90 degree drive rotary gear and on a 787 a balancer shaft all adding friction to turning over.

 

[GGuillot]

You applied 2 stroke oil in the cylinders and rotary valve area correct? I personally would have done a rebuild on the top end, that resistance you're feeling might be a rough cylinder wall where you attempted to remove rust and so forth. It's not going to be as smooth as fresh cylinder rebuild. It's just not often someone would do a crank and gasket/seals swap and not do the top end, but I understand the limited budget.

 

[Jetjon24]

The engine is outside of the ski. I am actually getting a donor hull on Sunday. I did heavily oil everything during the assembly (IE lube the crank and rotary shaft, coat the timing wheel with oil and then put more oil in it and spin it a bunch, put some in the cylinders before assembling and poor some down the cylinders and spin it after assembling). I don't feel any rub or grinding, it does spin smoothly. In theory, it is just the fact that it is under solid compression and therefore is hard to turn plus having new parts that need to be broken in. When I said it turns in stages, basically its hard to turn while one cylinder is under compression, then the compression releases at a point and it easily turns for a short bit till the other cylinder is under compression. I don't have anything indicating its wrong, but it just seems a little weird. I hooked up the starter and turned it with the sparkplugs out and it spun smoothly, but my battery is weak, so it wouldn't even try to turn it with the sparkplugs in.

The reason I didn't really do a top end rebuild is because my top end was so clean. Of coarse there are the pictures from earlier in the thread where I show what build up there was, but that's the only signs of wear or damage in the entire top end, and that cleaned up well. To be honest, this ski probably didn't have many hours on it, I just think it sat for too long. My jugs are clean and I have new pin rod bearings. I do understand that it would be a shame to do all this work and then have an issue with the top end though.

Thank you so much for all the input. I think i will try to crank under compression with a charged battery tomorrow and if all seems well, I'll press on and install the motor when I get a new hull. If it seems unbalanced or rubs, then Ill go ahead and tear it back apart before something goes horribly wrong.

 

[GGuillot]

My jugs are clean and I have new pin rod bearings. I do understand that it would be a shame to do all this work and then have an issue with the top end though.

You'll find out once you do a compression check.

I'm not doubting your abilities, but during assembly what did you use to seal the case halves? I see red at the seams... On the 96' 787 cases, since it doesn't have the fill/drain plug for the BS cavity, you put some oil (1 oz) in there before sealing the cases up? Did you put a little 515/518 on the crank seals? Chased the thread holes with a tap? Proper torque/loctite/grease and so forth where applicable by the SM? As advised above from @mikidymac may want to pressure check it..

Only asking to minimize issues later when you go to start it...

 

[mikidymac]

So..... the issue with just cleaning the rust at the top is that rust actually eats microscopic holes and pits into the iron sleeves. Even Though you cleaned off the surface rust the holes and pits are still there. This will cause poor sealing of the rings which can at best cause lower than ideal compression or at worst the burning off of the oil film in the pistons from the rings not sealing and seizing a piston.

Get it running then check the compression and decide from there if you want to roll the dice or not.

As GGuilot said, did you use the correct sealants and thread treatments? And check for air leaks?

 

[Jetjon24]

I used a little rtv to seal the case. I oiled the daylights out of everything during assembly. I did not tap the threads, I've never heard of doing that before. I did however clean off the bolts and followed torque specs as close as I could. I haven't yet done a pressure test. I searched online and on youtube and couldn't find a single thing about it. Could you guys either explain how to do it or link me to something that would explain it?

 

[GGuillot]

I used a little rtv to seal the case.

Might as well break it back down and do it over, that's not going to hold up for long. Oil and gas will deteriorate RTV and cause an air leak. You should use something specific to 2 stroke cases, like Three Bond, Yamabond, etc. I personally use Three Bond 1184.

I did not tap the threads, I've never heard of doing that before.

You do this to clean it up so you'll get a good torque, not absolutely essential, but a good practice, sorta like a baseline for a consistency.

For a pressure test you block off intake/exhaust ports, etc and carefully apply air and watch for a leak down. The SM you downloaded has a good description of the procedure.

I oiled the daylights out of everything during assembly.

Again, refer to the SM when in doubt, you still need some oil in that BS gear cavity. You have a new crank, don't risk it and skip this.

Forget youtube, not all the advice on there is reliable anyways...refer to the SM and this forum.

 

[Jetjon24]

Might as well break it back down and do it over

The truth hurts

I'm getting my new hull tomorrow. While I'm out, Ill pick up the parts I need and do it all over again. At least I'll be able to sleep at night knowing I did it right.

Thanks for all the help

 

[Madpaddler]

Yeah, I don't know why the 96' SM is incomplete for the GSX. I use the 97' download since I also have a 97' GTX, which includes the GSX, and the engine is the same as the 96' GSX. I use the supplement from the 96' download for the electrical.

I know this is going back a bit, but the '96 GSX and GTX came out just a fuzz later than the other models, so there is a SUPPLEMENT section of FSM you have to download separately. Below is the link to it, just FYI..

1996 SeaDoo GSX, GTX Shop/Service Manual Supplement - FREE PDF Download!

 

[GGuillot]

I know this is going back a bit, but the '96 GSX and GTX came out just a fuzz later than the other models, so there is a SUPPLEMENT section of FSM you have to download separately. Below is the link to it, just FYI..

1996 SeaDoo GSX, GTX Shop/Service Manual Supplement - FREE PDF Download!

I've rebuilt both of my skis, 97' GTX and 96' GSX, from bare hulls, so I'm familiar with what's in both SM's. What point are you trying to make? On the site there's no complete manual download for the 96' GSX, only the 96' GSX/GTX SUPPLEMENT, which is incomplete. That's why I mentioned the 97' GTX will work since it's 'complete', minus the specifics of some wiring found the 96' GSX/GTX supplement download.

He needs specifics for rebuilding the carbed 787 engine and other related items, the 97' GTX download will fit the bill for those specifics. If he's chasing wiring issues, like VTS, he can turn to the 96' GSX supplement.

 

[Madpaddler]

I was just making sure everybody knew about it. Wasn't trying to bust your chops man. I have the same two skis as you, and I know all about your builds. However, I wasn't sure if JetJon24 knew about the supplement and you didn't mention it. You just stated that the '96 FSM was incomplete and you didn't know why. My bad.

 

[Jetjon24]

Thanks for the input. I got the manuals all bookmarked and I've got a descent bearing as to where to find what. I just ordered the locktites i needed and some yamabond. I got that new hull and it was solid but the gel-coat was trashed, so i went ahead and gave her some paint. ***Let me preface this by saying I intentionally went with a cheap paint job because I want to see what I can do on a budget.*** Its more of an experiment for me than anything else. Realistically I'm hoping for 2-3 years out of this paint job and I want to know how well it works.
Keeping that in mind, I used 1 qt of smake grey rustoleum enamel and sprayed it on mixed 2 parts paint to 1 part thinner. Then for my final coat i mixed 80% paint, 20% thinner. At first, I ran into some problems with the paint running and whatnot, but that's because I am a novice with a spray gun.
I still need to add a few more layers of clear coat to get a glossy look, but I'm happy with it so far... and I only spent $20!



Also, for the bottom coat, I found this product for sale where I work that I really want to try. Its made for boat bottoms and is supposed to be Kevlar reinforced with graphite and other stuff to make it super slick. I'm kinda skeptical, but i paid like $4 (it was on super-clearance), so if i have to sand it and re-do it, that's fine, because the bottom of the hull is already stained and faded beyond repair.



Here's a question for everyone... So my friend recently payed over $100 for a really high quality totalboat painting set that came with the paint, mixers, and all sorts of stuff. He spent weeks prepping and busted his tail making it look good (and it looks great!). Here I am doing a cheap $20 paint job, which is turning out pretty good, but it really is significantly less work and money with comparable results. So for everyone who has painted their skis, or even just parts, what sorts of results did you get? How long did it last? and to what extent did you have to go to get those results? I know that you get what you pay for and that what you put into a paint job is what you'll get out of it, but what has been you guy's experiences with DIY jet ski paint jobs?

 

[mikidymac]

Paint doesn’t really last on skis no matter what you use. The most durable finish on watercraft is gelcoat. That’s why all boats and skis are gelcoated.