I'm am new to jet boats, actually brand new this is my first one and it is a 1997 seadoo challeger with a 787. I would also like to say i have learned alot from this site. To better explain my problem let me begin from the start. I bought the boat for 1000 dollars supposely had a newly rebuilt motor. When i bought it i was unable to test it in the water for a few weeks. So when i got it to the water finally, come to find out it didn't have reverse and neutral really isn't much of a neutral cause i hit the dock when it cranked in neutral lol. But this isn't the real problem. When i starting the boat for the first time it takes a while, then when giving it gas to go it boggs, then all of a sudden takes off and runs fine until idleing for a few min then it does the same. So i read alot of forums and decided it might be the rave valves well sure enough one of them were broke at the top where the threads are. Not sure what causes that. So now i thought the problem was fixed. Well it helped in running but the starting still occured and still had some bogging. So took sparkplugs out and one had white milky like liquid on it like water and oil. So decided must be head gaskets not knowing about he motor took the heads off and no head gasket but instead o rings. The heads and all looked fine. Began investigating and seen that the liquid was coming from the port or hole that the rave valves fit in. So figured maybe the exhaust gasket, So then i took my exhaust off and there was more white milky liquid inside it. So i am so confused can anyone help me. Also there is a rattling like noise coming from souds like the exhaust somewhere. Sorry for being so long but i am no mechanic so it is hard for me to explain. thanks for any help in advance.
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seadoo 787 problem water in cylinders
- Thread starter luke31186
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kcr357
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ADMIN EDIT: http://seadoowarehouse.com <-- Official Microfiche for SeaDoo Forum.
Here is a link to a parts microfiche, it will become your best friend. If your rave cap is stripped, I am thinking that some shadetree mech. may have frankensteined your boat and sold it to you. Does it have the bogging problem on land? You should go through your carbs. 13 years old, its about time if it was never done.
Check your compression just to be safe.
Was it ever ran on the hose while the engine was not running? That will fill the motor with water, but for it to get into the oil and create the milky substance your crank seals would have to be shot. Does it smoke a lot?
ADMIN EDIT: http://seadoowarehouse.com <-- Official Microfiche for SeaDoo Forum.
Here is a link to a parts microfiche, it will become your best friend. If your rave cap is stripped, I am thinking that some shadetree mech. may have frankensteined your boat and sold it to you. Does it have the bogging problem on land? You should go through your carbs. 13 years old, its about time if it was never done.
Check your compression just to be safe.
Was it ever ran on the hose while the engine was not running? That will fill the motor with water, but for it to get into the oil and create the milky substance your crank seals would have to be shot. Does it smoke a lot?
Thanks and yes it does smoke i think a bit much. And i think your right about the shotty mechanic there is alot of things i think is not right on the boat.
what all would be a good idea to replace while i replaced my crankseal and also is there any special thing i need to know or any tips.
what all would be a good idea to replace while i replaced my crankseal and also is there any special thing i need to know or any tips.
wouldnt start with crank-seals. Pull the carbs, go through them, pull the RAVES (valves under the black caps) clean thows, install new plugs gapped at .020, and fill up with good gas....think your issue is water/crap inside the crank assy.....pull plugs, disperse all the crap, then go though what i just mentioned.:cheers:
kcr357
Active Member
Good advice, no reason to start with the exp. stuff, but if you do have bad seals, I rec. just getting a reman from sbt/etc. The crank seals are an exp job, if you are going to do that, might as well just get a motor. Even if there was was water down in the crank, it still should not have any oil in it other than what is in mixed in with the gas. The oil cavity is sealed off from the rod ends. How long was it ran in the water? Long enough to burn out all the crap down there, or just a minute or two at idle?
i also have got the exhaust, heads, carburaters and all off right now changing all the gaskets. They should be here tomorrow. Most of the gaskets so far look rough or either are jus the liquid gasket maker stuff. If i was going to do the seals i would like to do them now, while i have it broke down some. If the rave valve was broke could this cause in any way to let oil and water mix, cause since i fixed the rave valve it has only been run a minute or two. Also to explain the mixture of water and oil or whatever im seeing is it is greyish white and actually gooey and there was a pretty good bit of it but only on one cylinder.
inspect the sleeve ofthe cylinder for any "black" lines running from window to window, if so, its cracked and needs replacing, but the "gaskets' you say were used, dont sound like there doing the job. After inspecting the crank assy, and all goodthere, buy a complete gasket kit.
kcr357
Active Member
re
The liquid gaskets could be a problem. While the cyl. is off try sticking a small dia. hose into the case and seal the other end to a shop vac hose. Use clear tubing so you can see if anything is getting sucked up. You can make a base gasket out of cardboard(I use cereal boxes) for a quick fix to diagnose the problem so you don't ruin the real gasket.
The liquid gaskets could be a problem. While the cyl. is off try sticking a small dia. hose into the case and seal the other end to a shop vac hose. Use clear tubing so you can see if anything is getting sucked up. You can make a base gasket out of cardboard(I use cereal boxes) for a quick fix to diagnose the problem so you don't ruin the real gasket.
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