94 GTX overheating

[ct_racer]

I was riding our 94 GTX on vacation when it started having trouble keeping high revs going. I tried for a minute but couldn't get it to run right so i brought it back to shore and pulled the seat to find the hull was about half full of water. two of the four studs that hold the main exhaust pipe had broken and the water was exhaust waste water.

Once we got home I pulled the manifold and removed the broken stud and bolt pieces and replaced them, put new gaskets on the manifold and reassembled everything. I made sure it would fire in the driveway and took it out to the lake to test it.

I fired it up and nothing was leaking so I stood next to it and let it run for a bit and it seemed fine. So I took it out for a quick ride and got about 200 yards at idle and the overheating alarm went off. I wasn't very far so i got it back to shore and pulled the seat and it was definitely warm. I pulled plugs and cranked it to check if water was in the cylinders and it wasn't but I dont usually work on marine so I don't know what to look for on an open cooling system. It seems to me that it isn't getting any water through the cooling system and I am wondering if and how that might happen from pulling the exhaust. All hoses and tubes are reinstalled and should be correct as they all had different size connectors and were only the right length to meet a very specific connector.

I have three questions.
1) is there a way I can just use a hose to test it in my driveway?
2) what are some possible causes of this problem? (hopefully not a water pump, I am hoping it is some kind of vacuum issue)
3) what are some ways that I can test to find the cause?

Hopefully you can help me, I have worked on many motorcycle and car engines and cooling systems but like I said I dont really work on marine. Any information you can give me would be appreciated, Thanks.

 

[Dr Honda]

1) Yes, and no. If you have a flush kit... you can hook a hose to the engine, but since the water will be flowing in from a different point... you could be behind the blockage.

2) You don't have a water pump for cooling. The cooling water for you engine is forced in by the jet pump. There is a hose connected to the pump nozzle (on the pressure side) and it comes in the transom, and to the engine. If your pump is making thrust... then you should have cooling water.

(more on this in a minute)


3) Nothing to test. It's a simple system... see below.


OK... as in #2, if you have thrust, you will have cooling water. BUT.. if you are running in a sandy, or grassy area, then the system could be plugged up. Also... when you put your exhaust back together... did you buy a gasket, or did you make one? If the new gasket didn't have any extra holes in it... you could have blocked off the cooling passages. That would keep water from pumping into the engine.

Let's assume you bought, and installed the proper gasket. Then, you need to take off each of the cooling hoses, and look for one that's plugged up. Also, used some compressed air to blow though the passages, to make sure they are clear.

 

[ct_racer]

Sorry it took me so long to get back to you, its been a hell of a week... j/k

No, what actually happened was I got a job shortly after I started this thread and moved. The ski is my parents so I never got a chance to take another look at it. Basically they never bothered to fix it and its been sitting in a barn (heated) for the past 2 years. Last weekend I visited home and asked them about it and acquired it as my own, so the project begins again.

Tonight I pulled the cooling hoses and blasted them with an air compressor. Everything seems clear to me, with the exception of when I pulled the inlet line there was a zip tie kinking the hose. Now, I'm not the greatest mechanic in the world but it seems to me that this would really get in the way of things. Let me know if that hose should be kinked but I am assuming that it shouldn't for i don't know, water flowing to the engine issues.

Other than that I have been prepping the motor to crank again after a couple years. I sprayed cylinder walls with WD and put a little 2-stroke in the cylinders. I need a new battery as well. Other than that I am hoping she should be good to go. Hopefully the carbs haven't gummed up. I will probably rebuild them over the winter but am hoping I can get a few weekends in before the end of the season.

Again, any pointers would be helpful.

Thanks

 

[ct_racer]

After talking with a couple guys at work they suggested I rebuild the carbs before cranking her over. What do you guys think? They also suggested going through the oil injection lines and system. This all seems like a lot of work, though not as much as a a rebuild if shes not getting oil. Is there any way I can tell if the system is working without ripping it all apart?

 

[ct_racer]

Ok, just put a new battery in and she fired up pretty quickly with choke for only a second. Pretty Smokey coming out the back too (white smoke). Rebuild?

 

[donkey]

did u go thru the carbs?n replace the fuel lines n clean selector valve?
if it sat for that long id expect it to smoke quite a bit when u first started it,should go away after riding it a bit.
as far as a rebuild goes check compression,135min ish,if thats ok then run it.

 

[ct_racer]

No, I really haven't done anything other than spray some WD on the cylinder walls and put a little 2 stroke in the cylinders, new battery, and go through the cooling system. After submitting that last post I realized stuff I put in the cylinders are probably made the smoke. I really just want to run it for a few minutes to see if the cooling system is working. Then again I also know me, and if it is working I am probably going to want to take it out... I mean, I will already be all the way at the launch.

 

[ct_racer]

Well, cooling system is good. She's getting oil. She's getting fuel. She's got fresh gas. I'm calling this one good to go. The only thing I really need to figure out is the motor seems to be shaking more than I think it should be. The mounts all seem good when I rock the motor back and forth. I believe this is what caused the initial breakage of the exhaust bolts. I will search around for something on here to see if I can find something, otherwise if anyone reading this knows how much engine vibration is tolerable it would be nice to know that. The top of the motor seems to be moving about 3/4 of an inch left and right combined.

 

[ct_racer]

Well, I'm calling this one. Got her out on the lake today and she runs phenomenally. A couple bogs at WOT but I'm attributing that to half bad gas. I think the vibration is from a slightly to low idle. Other than that I'm very impressed with how today went.

 

[donkey]

ah very nice!good to hear it!