Seadoo not running in water

[@anwe88]

Thanks alot! This was exactly the problem I had. I would not have found this by my self. I fixed my valve cover clearance by screwing 4 wooden blocks into a piece of thick plywood. Then glued 240 sandpaper to the blocks and rotated the cover over them, checking the clearance and kept going untill it was good. O-ring groove didnt need any machining since it was so little out of spec.

[@wadeshacklette8349]

I replaced the rotary valve cover on my 2003 GTI and it FIXED my poor starting problem. Thank you SO much! I’ve been tinkering with this for years trying to fix it. WOW!! I didn’t measure my tolerances, I just replaced it hoping it would work, and it did!! (I replaced the o-rings as well) $200 for everything. I got the valve cover from SBT!! 😊

[@JW-es3ho]

Interestingly, I called SBT and now they charge $185 for the same thing now lol In a few years they're almost doubled the price. They also take 15 days to get the unit back to you. Thankfully I checked mine yesterday and the clearance is .0125 so I'm right on the money. Great video btw! This helped me decide to check the clearance. Turns out, the previous owner had the wrong size bolts in there, the cover was barely holding on, the mating surfaces were covered in junk and one bolt hole was completely stripped out. So, I'm hoping I found my problem haha It's all buttoned up and repaired and I'll be trying it out tomorrow. If it start on the water hot, then it's fixed. If it doesn't, then it's back to the drawing board. My compression is good at 140, spark is good, carbs rebuilt with genuine Mikuni parts, so, this is the last thing. I hope this does it!

[@ironhorse220]

Thank you great video I am having the same problem with my 1998 season speedster it runs fine in the driveway as soon as it goes in the water won’t idle I will check to see if I have the same problem

[@ExplorewithZac]

Thanks Peter Griffen!

[@skun80]

Thanks for the videos mate, they helps me a lot with my 787 rebuild 👍

[@bhoehn24]

Thank you. Alot more to come

[@StansWorld]

Make sure you check inside gas tank 2 pick up lines are prone to split and or fall off completely. 99% of my experience when they run great out of but wont run under a load its a fuel issue usually...

[@daveharmon3134]

Another great and informative video, thank you! I have a 96 GTI and last Saturday I found myself in 6" of water with sand below, unfortunately I panicked and rather then killing the motor, I hit reverse and then proceeded to get back in forward and drove out. Within 1 minute I heard a loud, high pitch winding sound and the ski began idling extremely rough and lost power. I tried cruising back with no throttle but within 5 minutes the engine temp light came on, I shut it down and got towed in. Since then I have done a compression test, examined the spark plugs, bumped the starter with plugs out, examined the shaft, impeller & wear ring, blown out the the water intake line (felt clogged for half a second and then blew through, thought that was it but no cigars), ran water through the coolant system in both directions and like the ski in this video, runs fine in the driveway but horrible when you put it in water. Next I guess I will check out the impeller shaft reservoir to see if sand got in there possibly. I would have thought this would've been a common, easy to diagnose scenario, but I'm not finding anyone else that has experienced this problem. Any suggestions would be greatly appreciated.

[@bhoehn24]

If it runs fine in driveway but runs rough or won't start in water. It sounds like a issue with the intake. As long as the compression is fine. The whistle sound might be a vacuum leak. It could either be from intake or a crank seal melted. I would start looking in that direction

[@daveharmon3134]

@@bhoehn24 The high pitch sound was only for maybe 3 to 5 seconds, have not heard that since. Anyway to test intake or crank seals?

[@daveharmon3134]

I did another compression test and each cylinder held 137 compression for an hour, not sure if this proves crank seals are good or not?

[@daveharmon3134]

Got it figured out, once I got the pump off I found that the drive shaft spline and or pto fly wheel were stripped out, I guess taking in a little sand at the impeller was the straw that broke the camel’s back. Do you think I need to replace the impeller too, doesn’t seem stripped out but had a bit of surface rust at its inner spline receiver? Also, there’s a little bit of back and forth play on the impeller shaft, is that normal or should I take it apart and have a look, I got an SBT rebuild kit coming?

[@chadharmon285]

I finally took off my rotary valve cover this weekend. But don't have a pair of calipers. Do you think I could just order a new one without measuring mine? And call it good.

[@michaelcorbo6458]

Tried your boiling parts in water seemed to really help

[@haithamrifai4570]

Can you please advice the clearance with the O-ring, or the diameter of the ring, because my ring is not OEM.

[@bobtyesimmons2671]

Do you have a video for removing carbs on 99 gtx? I want to clean. After 3-5 minutes or running WOT ski starts to run rough/idle and doesn’t accelerate

[@jaimemedina9178]

Thanks for the video. I have 1990 seadoo bombardier and having same issue. I just bought it. I'm from Edmonton Alberta. Any idea if its available on my location?

[@chadharmon285]

Sorry to keep bugging u but I'm all most done with my ski!! Do u think I can just order a new rotary valve cover from sbt and put it in and hit the lake. Or do I have to measure my cover? Does SBT need any measurements from me when I order a new one?

[@bhoehn24]

No they don't need any measurements. Just order a new one and send back the old one after the new one comes.

[@chadharmon285]

@@bhoehn24 ok thanks alot bro!!

[@JosephMcKinley2005]

Thanks I have the same problem with my 1997 seadoo xp I can start it on the trailer in the driveway but when I put it in the lake it doesn’t start it just turns over

[@Danny-zw1yn]

did you fix it i’m having the same issue

[@bryanrivera0919]

Has anyone solved it? I have the same problem

[@PawPawsSpeedshop]

Thanks a ton

[@kickeringles3900]

I mess up taking the plate out didn't mark it was the proper position piston is up

[@pwrcycles4735]

Wondering if you could have similar problem with rave valves.? I had the same issue ski won't run in water but I have rave valves has anyone had experience with those..??

[@bryanrivera0919]

Hello, I have the same problem but I also have a Rave valve, were you able to solve it?

[@gabrielgagnon7399]

Thanks you..

[@robertwright1139]

Do you have an address for the SBT company where can I find them I have the same problem

[@bhoehn24]

That could definitely do it if it's loosening compression

[@TheCbond]

Do you still work on these engines? I'm in NY area and need help with my 97 Seadoo GTX.

[@Joe_Dallas]

Hey mine revs up on land but when it hits the water it goes vary slow full Wide-open throttle I adjusted the Carbs and Pre-mixed it

[@kevinakagohan]

How about if it runs but for like 8 minutes and pops a fuse 15? Battery would be perfectly fine but next day would be dead even after putting new fuse?

[@bhoehn24]

Something is shorting out in the computer box. Disconnect the rectifier and see if the battery holds a charge. If not then disconnect the mpem. More than likely it's a bad rectifier

[@adamw5102]

You would have to check and see what the fuse controls and look for a short to ground. The battery could be old and weak or there could be a parasitic draw draining it.

[@adamdesalvo6949]

I have found new computers on line for 200 bucks that don't need programming u use ur existing"key" that when I thought mine was bad.

[@Thirdplace4life]

But this doesn't make sense. If it's your rotary valve then you would always have a starting problem. I don't know how it would affect it being water.

[@chriseaster5666]

Hello, so I have the exact same problem on my Sea-Doo. It's 2004 gti LE with 720 motor. Complete new rebuild -crankshaft, bore/pistons, rotary valve gear/plate and a new sbt rotary valve cover. Carb rebuilt. It ate the rotary shaft gear, bass flew everywhere inside and killed the it. Basically new motor top to bottom. Followed the shop Manuel on everything. Cranks, runs perfectly on land but will not crank/run in water. Even tried to crank on trailer and backing in water, it dies. Someone suggest my forward/reverse gate is set to low causing water back pressure, however it's set identical to its twin gti that just required a top end build. Any thoughts suggestions??? Would really appreciated being able to enjoy this money pit!!!! Thanks.

[@bhoehn24]

Did you change the valve plate with a new one or used. Cuz that's usually the problem. There's too much clearance between the plate and valve. The clearance has to be between . 012 and .014i believe. STB sells one that's re machined for $90.

[@chriseaster5666]

@@bhoehn24 plate meaning the spinning 159degrees cut half moon? it's New. Then a re machined rotary cover from sbt also. But everything rotary valve associated is new, new gear shaft, new plate, new machined back to spec cover. I guess I would have to pull and measure, to completely eliminate that for sure. I just thought since the plate and cover are both new there made to spec?..... I did find a small oil leak on the return side oil line "aka exhaust side" of engine case that I fixed- my thought was since that was pushing oil out of motor as opposed to into(carb side oil case line) it would not produce a internal engine vacuum/pressure leak?. Haven't had it out /in water since that fix. Not positive that was/is the solution. Carb pop off pressure in spec. Low and high speed idle set per spec. New wear ring on pump. Dam near New sea-POO except hull of boat 🥴 I'm thinking its something very small and stupid I over looked? Thanks again for the help and quick reply Capt.

[@bhoehn24]

It sounds like everything is new and within tolerance. The only other thing I can see is the mpem being bad. If compression is good, fuel circuit is good, rotary valve and intake is good then I would start looking into ignition. Also what about rave valves? I'm sure you looked into them too.

[@chriseaster5666]

@@bhoehn24 720's don't have rave Valves - 787 /951 do. Got to be something stupid, guess I double check the tolerance of rotary valve, check exhaust for bird's nest/ clog. There are some test I can do on the mpem too. I'll follow up after my work weekend. 😵😵😵

[@breannagriechen701]

backwards pistons

[@chrispederson4157]

My 2005 seadoo 3d has 180 hours on it 787rfi engine. Do you think this could be my problem. Start great and idles fine but will not excerate or get on plane kinda like a bog. Ran great then all day loaded up ski a week later as soon as I put ski in water has done it. 155 psi compression both cylinders. 58 psi fuel pressure while running and difference when it will nor execrate. Checked injectors seem to open and close with 9volt battery and cleaned with carb cleaner while out. Seem to spray fine when hooked to rail and cranking. New battery 14.1 volts while ski is running at battery. Checked all sensor with multi meter and all seem fine. Did not start ski for 4 day then held paper towel over spark plug hole tight and no sign of excess oil at all on paper towel. Repeated 2 more time looked the same which should tell me not a crank seal or rave valve seal leak. Inline spark plug light flash like both cylinder is getting signal to spark. Can unplug mag or pro spark plug and ski will start and run the same. Thanks for any help.

[@chrispederson4157]

No difference in fuel pressure when trying to speed up and bog happens.

[@danielpaezbarajas]

HI Chris. I have the same issue. Did you manage to fix it?

[@chrispederson4157]

@@danielpaezbarajas Not yet.

[@georgejeudevine4434]

I have a 1996 seadoo sp having similar issue, jetski starts fine out of water and will start in water but once it shuts off it wont start back up untill on trailer out of water. Any ideas

[@lifewiththehamptons2191]

My 99 GTI 717 is doing the exact same thing. It will crank up in the water when it’s cold, but once it’s at running temp and you stop at an idle, it tries to bog down and quit running, if you do let it die when it’s warmed up it is a nightmare to get cranked back, if you get it cranked back. Usually if you let it sit for 30-45 minutes after you initially try to crank it back, you can get it started back. Crazy thing is that it will run amazing all day long until you go to an idle, or shut it off. All new fuel lines, brand new Carb, all fittings and vents, and filters cleaned. I’m now leaning towards the rotary valve, but I have NEVER fooled with that part of a ski. A little intimidating

[@wadeshacklette8349]

@@lifewiththehamptons2191 I have the EXACT same issue with my 2003 GTI 717 Seadoo. It starts out of water great. I can start it cold in water most of time and it runs great until I stop. Then it won’t restart when warm/hot engine. Did you solve your problem? (Please help! Very frustrating)

[@wadeshacklette8349]

Hi George, did you ever solve your Seadoo starting problem in the water? I’m trying desperately to figure a remedy for mine. Any help would be appreciated. Thx

[@georgejeudevine4434]

@@wadeshacklette8349 I believe its the rotary valve clearance possibly. I need a top end rebuild as my compression is low now on this ski.

[@StansWorld]

I got another that will not start in water I am gonna check that good info ......

[@32gofastbeard]

I have a 2002seadoo GTXRFI will run good on hose put it in the water and it won't run over 4200 rpm

[@danielpaezbarajas]

Hi Shawn. I have the same ski. how did you fix it? did this work?

[@zachmoore4454]

@@danielpaezbarajas did you find anything out?

[@victorugalde2000]

Have mate I need help whit my ski 96 gtx seadoo the last owner take the oil container out thinking to just mix the oil to the gas out side “ that’s fine the problem is it think wast done the right way because now I get a heating alarm every time I go on the water and water is not the problem, how I can bypass the alarm ? Please help me thanks

[@bhoehn24]

Do not bypass the alarm . It's there for a reason. I would check the wear ring in the jet pump. It sounds like your not getting enough water flow. How hot is the water coming out the back pissers?

[@8bert9]

I hope all worked out because if the previous owner took the oil injection tank out it needs to go back in. That tank has to larger lines that feeds oil into the center part of the crankcase to lube the rotary valve gear! It will be destroyed in no time running it dry! Peace!

[@mw101376]

I’m gonna run this by you to see if you might know what my issue is. I found your video on KZbin as I’m trying to find someone who has same results as mine. I have a 97 GTX 787 that runs awesome on the trailer and on the hose. But when I put it in the water, idles fine but give it gas and it won’t get up out the water or reach above 4000 rpm. I’ve had the following done to it, new wear ring, another jet pump installed, compression check which was good, carbs were adjust and cleaned, which were not bad anyway, new spark plugs, new plug wires, new gas lines, new 100% gas, gas filter was checked and is fine, new rectifier, and it’s still not getting up out the water. I cannot figure this out for nothing. I need some help on what else it can be. I’ve already put over $1000 in it and I only paid $500 for it. What else can it be?

[@bhoehn24]

I would look into the rave valves and the rotary valve cover. In the manual it says I believe 16 thousands clearance. The book tells you how to check it. SBT offers re machined ones for around $80. And make sure the race valves are clean. Also was the impeller changed at some time with a different pitch?

[@mw101376]

Capt n B garage thanks for the reply. The jet pump I swapped with already had the impeller on it so it didn’t change anything. I broke down today and just went ahead and took it to a local shop that works on skis for over 20 yrs and after he looked at it, he still believes it’s the carbs and also the high input and low input may have been tampered with previous to my ownership and he said those are not supposed to be touched. He also believes the timing is off so he’s gonna look at that. And we looked at the gas filter and it had trash in it so he’s gonna clean out the tank. So new carb rebuild, timing adjustment, tank clean, and new rave valve gadgets and manifold gasket, around $500 estimate. I’ll update when it’s fixed on what all was wrong. Thanks again!

[@aaronallen4647]

CarolinaGamecock any luck?

[@mw101376]

Aaron Allen I ended up taking it to a shop to have it looked at. Spent $1200 to fix. Had to have a new inline gas filter, new oil filter, new gas and oil lines, new rotary, carb rebuild, new ignition coil, timing had to be reset, and I’m sure I forgot something. Got it back on the water and would haul butt again, but then it would die out on me after riding about 15 min. and couldn’t get to crank in the water. Took it back, and they replaced the fuel sending unit in the gas tank. They went out to test it and the engine blew up! They gave me a $1000 credit to put towards a Yamaha. So now I have a 2010 Yamaha VX Sport.

[@aaronallen4647]

CarolinaGamecock crap!!!

[@gabrielgagnon7399]

Hey my seadoo gtx 800 rfi 1999 run well on the road but not in the water I have the same difficulty that u explain in this video.. but my seadoo start after a moment when I try to start it.. its normal that I work after a moment?

[@32gofastbeard]

Did you get it fixed mine is doing the same

[@gabrielgagnon7399]

Yeah it’s the rotary valve that have a clearance

[@32gofastbeard]

Do the 2002 rfi have the rotary val.

[@chadharmon285]

So did the valve cover fix the problem? Did it start in water after that?

[@bhoehn24]

Yes it did. Ran perfectly after

[@chadharmon285]

@@bhoehn24 ok great. Thanks a lot. I was having the same problem with the same ski. I was waiting on a stator I ordered. I'm going to send that back and get that cover instead. I will let u know how it turns out.

[@bhoehn24]

If you contact STB they will send you a remachined one and you have to send back your core

[@chadharmon285]

@@bhoehn24 stb.com? Nothing came up

[@fishingthe2528]

my Tigershark doesn't start in water and it's not a rotary engine or a rotex engine I rebuilt the carbs nd still doesn't start in water

[@bhoehn24]

Does it start out of water? Usually when it doesn't start in water is because lack of power. Start with compression and check reed valves.

[@fishingthe2528]

Capt n B garage yes it starts out of the water it runs good out of water

[@bhoehn24]

If you didn't already I would start with a compression test. Should be around 150 psi. If that checks good then possible crank seal

[@fishingthe2528]

Capt n B garage the middle Piston has a chip in it so could that cause anything to do with it ?