My '92 (#3) is overheating

[tomski]

I've searched a few posts regarding this issue ,but I wasn't sure if they were the same things as what I have going on.

So far , I have replaced all the 1/2"main hoses, blew air through everything possible. Removed the cap(head) exposing the top of cylinders. Vacuumed out very minimal sand particles. Put everything back together. On the trailer, the engine runs great and the head is very cool. When I run it in the lake, the head starts to get very hot, it overheats and shuts down. I believe the problem could be the jetpump.... or, if anyone has a top 5 causes for this overheating problem. Thanks for any help

 

[mikidymac]

Typically a bad wear ring or the seals from the pump to the cooling line.

 

[tomski]

This is the same ski that wouldn't run properly after replacing the wear ring. Eventually finding out it was a bad coil. I think I need to revisit the wear ring replacement job and see what went wrong.

 

[tomski]

Hi guys...so based on these pics, can something be seen that doesn't look right or....I have not found any blockage or restrictive airflow (waterflow) anywhere. That is a new wear ring.

 

[mikidymac]

Pump appears to be ok.
How is the flow out the pisser?

 

[tomski]

When in the water, both pissers flow like a teenagers'...I'm going to switch out pumps to see if there's any change...
"For those tough to pull pumps!"

 

[mikidymac]

If you have good flow then it isn't the pump.
You need to blow out all hoses, make sure all hose routing is correct.

There is a little sand in the head but can you see down into the cylinder water jackets and verify they are clean?

There is nothing on these that would cause it to "overheat and shut down". If it gets so hot that it shuts off then your engine is seizing. Check compression. If it is a lack of water flow and it gets hot it will melt the rubber exhaust couplers and burn the white paint to brown on the cylinder exhaust outlets.

 

[tomski]

I've replaced all the hoses and according to the other skis, the routing is all identical. I did do exactly that when I had the head off. Attached a small hose to my shop vac and was able to suck out anything that might have been there at least on the exhaust side. ( the holes on the carb side were considerably smaller so blew out anything I could) it looked really clean. I understand the getting hot and shutting down. It is like it seizes up. When it shuts down, of course I need to get back to the dock. I wait a few minutes, and fire it back up to get me back only at idle. It's only when I get back up on plane, it really warms up and then,yes most likely seizes up and stops but it fires back up again. Pretty weird . I've got nothing melted

 

[mikidymac]

Please do a compression test, then engine should never shut off and be hard to start.

 

[tomski]

I understand, but after that short wait, It fires back up immediately. Mag side isn't looking good.

 

[tomski]

Plugs look identical and very good yes?

 

[mikidymac]

They should be dead even.

 

[tomski]

Yeah...

They should be dead even

this #3 ski is really being a pain in the ass. Well, I switched out pumps anyway. I'm going to run it tomorrow and hopefully something fixed itself!

 

[mikidymac]

If it keeps shutting off you need to stop using it or it will just cause more damage.

 

[tomski]

Absolutely..when I get out on the water, I pretty much find out right quickly that somethings not right. I don't want to wreck it, but I do have to run it after everything I did for her today.

 

[tomski]

**UPDATE **
After changing out the jetpump, there was zero change with my overheating/ shutting down issue.
@ a little more than 1/4 throttle, I could get around the lake fine. I lifted the seat and could feel the engine was running hot. I hammered it down a bit (heading towards the launch of course) and sure enough, she shut down. Waited a few minutes, drizzled some cool lake water on it, fired it up and got back to the launch at idle and loaded her up. What am I missing here?

 

[mikidymac]

Just guessing at this point but with one cylinder considerably lower on compression and the shutting off I would think that cylinder is running lean and seizing which will cause a lot of heat.
I really don’t think you are actually overheating due to water flow because you aren’t melting exhaust hoses and discoloring the paint.

 

[tomski]

Yes, that does make sense. I am going to switch back to the original rebuilt carbs that were on it from the get go, and see if that's what's happening. I totally understand about the compression being lower than the pto side. I just hope that I didn't take it to far and really have a issue.

What ever happened to Matt Bradley.

 

[tomski]

Sorry, should have asked that on "OFF-TOPIC"

 

[mikidymac]

Not sure. Matt went radio silence a couple years ago.

 

[tomski]

To bad..he to was helpful.

 

[tomski]

**UPDATE **
After changing out the carbs, I'm not shutting down, but it does seem to still be running kinda warm. I'm considering going to the BR9ES ...I run 7's in all the others. Plugs on the left with the other carbs..mag side plug on left of left pic.

 

[tomski]

Top top left....