98 Speedster starboard engine over heats HELP!!

[sxsuperfly]

Hi Everyone,
I just bought my first jet boat after years of running outboards and have tryed to run the boat at the lake twice now with one problem after another. After extensive cleaning and rebuilding the carbs on both motors because the right motor would only run on one cylinder now the right motor overheats and makes the alarm go off (it is rediculously loud!!!!)
The starboard engine doesn't have any water coming out of the exit pee hole next to the jet pump when I hook up the hose to the lower flush inlet. Some thing must be plugged but I don't know how to unplug it. The port side motor has water coming out the pee hole just a few seconds after turning on the water. I'm new to these jet boats but if running the motors and flushing them with a hose under presure doesn't work to get water to come out of the outlet then what do I do next?
I tryed using the hose to force water back through the pee hole to back flush it but I couldn't get any water to go in with the hose turned all the way open!!! It acts like its plugged solid.
So far I've thrown alot of money, hard work and skinned knuckles into this boat and I just keep running into more problems and this one I don't know how to fix.
Any help/suggestions would be greatly appreciated
Thank you

 

[racerxxx]

Are you using the hose connection on the back of the boat? If you look you will see a plug and a white wing nut in the below pic. I do not flush my boat thru there, I use the ones under the hatch in the second pic. Also, when you start the engine --THEN turn on the hose, do you get ANY water out the back of the boat near the tow ring(near the grab handle on the back hatch).

You are going to have to remove each hose individually and blow compressed air thru them to make sure they are clear of obstructions. I just repowered a guys Challenger with twin 787's and almost every line on one of the engines was plugged with what looked like wax pollen. This goop shot all over the place. Also, check the short black hose going from the front of the cylinder head cover to the exhaust pipe(first pic), it's 1/2" hose. Remove that hose and check that the outlet of the cylinder head cover is not plugged solid. One of the old engines I removed from this guys boat was plugged tight and casued his engine to overheat. Look at the lower half of the exhaust, is tit silver colored or a coppery bronze/silver by the exhaust coupler to the water box (as seen in second pic, black hose with two large hose clamps)


You can see the large 1/2" hose from the head to the pipe. I would start here. Be careful when removing the hose from the head, they can get very weak from corrosion. You might want to cut it off and hit the auto parts store for some 1/2" heater hose., Then with a mirror look back into the nipple coming from the head. If it's blocked get a shop vac and set it up to suck the crap out while you slowly and carefully chip away at it with a pic or something like a small screwdriver.

Here is the area for you to check the color of the pipe, find the red cap on my pic and look straight down to the rubber coupler, then look forward--Is your pipe discolored ? If so you probably have a bad water control valve too, but you still have to verify the lines from the pump to the engine to the pee hole. Where you at in NY?

 

[sxsuperfly]

Thanks for your help. I live in Owego about 20 miles from Binghamton and have an hour drive to get to the lake each time I put it in the water only to find another problem and have to load it up drive an hour back home. I bought a 1998 thinking that a couple of 800 2-strokes would be easier to work on and parts are cheap and readily available. They sell rebuilt long blocks on e-bay for under $900 so I thought this would be something I could maintain and even if one of the motors puked I could replace it for under a $1000. I've worked on 2-strokes since I was a kid and have rebuilt many motorcycle, snowmobile and outboard 2-strokes but none of them have been more frustrating and hard to work on than these 800's. The last thing I thought would be a major problem is the cooling system. The cooling system is a complicated mess and a really crappy design prone to plugging and overheating. I still don't fully understand how the cooling system works.
I looked at the micro fiche of the cooling system and the pee hole outlet hose runs to the front of each cylinder under the exhaust manifold.
This would suggest that the water from the head makes its way to the cylinders and out the pee hole but the 90° elbow fitting and the tee fitting is under the manifold so you would have to disassemble the exhaust system just to varify that the fittings aren't plugged. I ran a coat hanger as far as I could up the pee hole until I got to the tee fitting under the exhaust manifold. Standing on your head to work on the motors is really hard and if you drop anything it magocally disappears under the motors somewhere. I wish there was a Seadoo boat dealer within a couple hundred miles because I'd let someone who know about the coolant system see if they could figure it out and if it was going to cost too much I give it to them to put up for sale. I've spent over $700 and many hours standing on my head trying to work on this boat and it has been a huge disappointment. I bought a new 2012 skidoo XRS 800 E-tec ($12500) and it has a check engine light on and runs like crap with only 200 miles on it. I've lost my confidence in Bombardier products after having spent over $20000 on new and used bombardier recreational vehicles only to have problems with them even if they are brand new!!!!!!!!!

 

[Coastiejoe]

I think Racerxxx is on the right track.

Sounds to me you have plugged or partially plugged cooling system.

It is a very common issue.

 

[racerxxx]

Well, I think part of your problem is, your boat doesn't have 800's, it has 720's. I would assume by YOUR description of where the pee line comes from UNDER the exhaust manifold that your boat is a Speedster SK. I would ASSUME that you also have a hard bow cover. The plain Speedster came with the 800's and a seat up front, no bow cover. Does your engines look like this one? You can see the clear pee line off the side of this exhaust manifold, this is an 800. Also does your engine have the black caps with the red adjusters in the center, if not you for sure have an SK with the twin 720's.

Or does your engine look like this (with a different color exhaust pipe) 2nd pic is just the exhaust manifold

Speedster SK with the bow cover(your's probably has different graphics)

 

[sxsuperfly]

Well I took off the hose between the head and the exhaust manifold and it is clear. I also took off both hoses connected to the other side of the head and blew through them both and they are clear. I then hooked up a shop vac to the head and sucked out anything that was in there. I think the blockage is in the cylinders themselves or the elbows and tee fitting that connect to the pee hole which means the exhaust manifold would need to be taken off to even see the fittings. That is alot of work. Everything I have taken apart has stainless bolts and everyone except a few has broken off requiring hours to get the broken bolts out - very frustrating to say the least. Is there anyway to blow compressed air back through the hose connected to the pee hole?? I hooked the hose up to it but it's not enough pressure to clear it out.

Thanks for your help - I'm going to give it another shot but I'm pretty close to giving up - somethings were never meant to be!

 

[sxsuperfly]

Sorry I should have specified what Speedster I have.
The boat is a 1998 Speedster 1600 with twin silver 110 hp 800(787) motors. Not an SK with twin 85hp 720's. It has the optional padded red bow insert that locks in and closes and covers the whole bow section including the seat.

 

[racerxxx]

Post a pic of your boat, and a shot of your engine bay.

Here is the cooling system, it's very straight forward. The water enters the head on the low side of the two hoses. That inlet line has a "T" in it that also feeds the water control valve. That control valve will inject water into the main pipe thru a 1/4" black line, which will then ride thru the lower half of the pipe and into the water box and eventually exit thru the exhaust. Now back to the engine, the water has entered the low side of the cylinder cover and flows across that and exits the front and into the main head pipe and flows up that and feeds into the exhaust manifold which will fill the cylinders and then exit the cylinder head cover on the upper black 1/2" hose. That hose goes back to where you can connect the garden hose back by the pump. But off the exhaust manifold is the pee line or tell tale line. That is the small 1/4" clear line off the EM and exits the boat near your grab handle, water must come out there, this is your eyes telling you that water is flowing thru the system. It just sorta "flows out". There is also the two calibrated fittings in the bottom side of the cylinders that "T" into each other and will also drain on the opposite side of the pump, iirc.

It's gonna be a b!tch but you really need to verify every line. It's not really a bad job, but I assume that you still have the hatch on which is making you hate this boat. That has to come off to work on them if not you will lose your patience quickly. Spray the under side of the three screws on the hinges that are mounted to the boat with WD and keep doing that. Let it sit a day or so then SLOWLY start to back the screws out and spray them (top side) and work them back and forth until they are all the way out. DO NOT try and just remove them w/o going back and forth unless they turn out real easy. It's not a bad job, but the exhaust will need to come out to verify those lower calibrated fittings.

 

[sxsuperfly]

Wow special thanks racerxxx.
It took 140psi on my compressor to get the pee hole tube unpluged!!!! I alternated between my shop vac and my air compressor and finally got it unplugged. I blew out all the other lines also and put it together and hooked up the hose and water shoots out the pee hole now just like the other motor. I wouldn't have thought to use an air compessor but now I know---------

Thanks for the info guys

 

[racerxxx]

Cool, but does it still over heat??? Glad I could help get you in the correct direction.

 

[amcgarva]

yeah, compressed air is going to have a lot more force than anything the garden hose or your motor will put out. has anyone tried water from a pressure washer? It should have more force yet.

 

[Coastiejoe]

If there is a bit of water in the line then you use air it ups the pressure as the water isn't compressible.