650/X-2 650sx - can't keep it cool

[whennotsailing]

I have a friends 650sx that I offered to repair for him, I cannot for the life of me get it to run well for more than about 20 minutes before it gets hot and boils the fuel out of it. Did a leak down test, checked all the cooling lines, etc and nothing obvious pointed itself out.

Tonight I took it all apart for about the 14th time and made sure nothing stuck in the jug, head, or mainfold, it's all clean.

Then a thought crossed my mind tonight, because everything else obvious hasn't fixed it... - Check out these pics of the exhaust manifold gaskets... The ski has a b pipe on it and single line cooling, friend claims it ran well back when he used to us it (it has been sitting for 8+ years, so i'm not sure he remembers)..

I wonder if enough water is getting through these gaskets ? I assume they were b pipe supplied ? Also bear in mind the head pipe gasket is sealed off, so my thought is just not enough overall flow ?

About to sink this thing for good if I can't sort it out. Been fussing with it on and off for 2 seasons now.

 

[jaxrider]

Those gaskets look correct. How is the water flow coming out of the pisser. Pic of the water line routing

 

[bobob729]

Is the water steaming after a bit? I had a problem similar to this and it ended up being a rock stuck in the coolling brass 90 fitting off the head

 

[whennotsailing]

By pass is your typical out the head pipe and back into the end of the stinger with a pisser over the side. Don't have pics because it's all torn apart at the moment. I do recall the flow out the pisser was pretty slow (its an old ski, haha)

The 90 elbow(s) might be worth checking...

Other thoughts ? keep 'em coming. What is the down side if I ditched those manifold gaskets for some regular ones to let more water through and then restrict flow with a dial on the 'out' side of things ?

 

[Nemo]

Strap the ski to the trailer. Put the ski and trailer in the water and pull the line off the exhaust manifold or the bulkhead and start the ski for a few seconds to see the flow from the pump to the engine. Then hook that line back up and pull a line coming off the head and check flow for a couple of seconds coming out of your engine. Continue through the exhaust and the rest of your lines. Should find the problem pretty quick.

 

[kswiatk]

By pass is your typical out the head pipe and back into the end of the stinger with a pisser over the side. Don't have pics because it's all torn apart at the moment. I do recall the flow out the pisser was pretty slow (its an old ski, haha)

The 90 elbow(s) might be worth checking...

Other thoughts ? keep 'em coming. What is the down side if I ditched those manifold gaskets for some regular ones to let more water through and then restrict flow with a dial on the 'out' side of things ?

Those are the normal gaskets. Kawsaki restricted water flow in the cylinder to prevent hot spots and keep the engine at the right temperature. It is best not to have the normal gaskets and not drill them over.

 

[Vumad]

I do recall the flow out the pisser was pretty slow (its an old ski, haha)

Seems like the obvious answer.

Blow out everything cooling related, except the motor itself, with an air hose.

 

[Quinc]

Replace all of the cooling lines. Including the one on the pump.

 

[Captain PegLeg]

And run dual cooling while your at it.

 

[whennotsailing]

Problem continues. Rebuilt top end of ski w/ bore and new pistons and went for a test ride yesterday. I know all the water passages are 100% clear. Engine was at about the right temp when it failed to run well, so doesn't seem to he a hot issue.

Talking with a knowledgeable someone the other day, their thought was stator may be getting warm and shorting. Thoughts ? Ski ran really strong for 30 minutes or so, then just completely falls off, will either shut down or idle only. Any throttle applied whatsoever will kill it. Let it sit for a few hours and the same symptoms repeat themselves, runs well until it doesn't.

Is there a test sequence out there for the stator ? On lawn mower engines I know you could ohm them out. (Not always a reliable test I know, but its a start). What about CDI ?

 

[whennotsailing]

Anyon have some thoughts? Help me help me

 

[bobob729]

never hurts to change the stator and find out but thats all i can say or maybe a bad coil thats heating up over time and causing issues

 

[whennotsailing]

I know things can test good even if bad, but is there any tests I can do just for the fun of it?

 

[Andrew1289]

I feel your pain. I am working on a friends 650 as well. I finished rebuilding the thing for him. Found it was over heating. Pulled hoses off while running to find one was not pushing enough water through. I found the head gasket to be leaking. I replaced head gasket, and it ran well. But I noticed the pisser water was too hot to keep my hand in. Some one else took it for a ride when I was away.

Lost compression in one cylinder. Found it grabbed a ring and scuffed up a piston. Leads me to believe all the running it hot damaged the top end. Thats why the pisser was so hot? I honed and put a new piston and new rings in the thing. I have yet to try it out on the water yet.

It sucks working on it because even if I get to to run correctly, its still a kawi 650.

 

[kevbo]

How can it have a cooling problem? Kawi 650s are the coolest skis ever.

 

[Pro-pulsion]

CDI. It happened to me the first year I had my second 650sx just a few years back. It had a replacement WSM CDI and like your experiences, it would run great sometimes for an hour, sometimes it wouldn't get past 30 seconds, would idle all day though. I put a used but known to be good CDI in and never had another problem with it. Just as kevbo said, and hopefully it wasn't sarcasm lol...but they really are the coldest running ski I have ever seen. If for any reason you think there is not enough water getting through the system, drill out the brass 90 degree elbows. They are made with a restricted internal spot just before the square corner reducing the i.d. to half of what it would measure at the barbed end. The nice thing with this ski is that it is already plumbed for true dual cooling at the engine compartment/pump area. I forget exactly which tube it is going through to the pump but one is strictly meant for the stock exhaust as a water dump off to help the pipe drain and stay relatively water free when being run. Just drill and tap in a 90 degree 1/8 NPT spot in your pump...after you bore out the little internal restiction...put a hose to that water dump tube and supply water to wherever you wish.

One for the engine, one for the pipe, or two for the engine at the bottom of the exhaust manifold and one off the head to the pipe like stock, either way you have options. There are lots of things that can be done to these skis to really make them a bunch of fun. My old 650 after modding the crap out of it was a real blast. The best part, most of the mods can be done for free as they are just correcting many areas the manufacturer overlooked during mass production. Here is a link that might give you some ideas to get that extra bit of fun out of your ski.

http://www.x-h2o.com/index.php?threads/completed-650sx-build-from-50hp-to-60.54481/

Oh one more thing, the stainless exhaust manifold gaskets you have appear to be the correct ones according to the microfiche. When new, the stainless gaskets have a thin silicone-like coating on them. If it has flaked off the gasket is still good. I love those stainless gaskets just for that reason. I have re-used those gaskets multiple times. Just add a very thin coating of ultra black silicone sealant to both sides and allow it to cure, you will be back in action.