OMC Crossflow v4 115hp Turbojet - Overheated/Ignition and Head Problems

[tmfeaster]

Re: OMC Crossflow v4 115hp Turbojet - Overheated/Ignition and Head Problems

I discovered my problem....water is freely flowing through the valve assembly at all times which is preventing the engine from building up water pressure which in turn is preventing the water from flowing to the top of the heads and the rest of the coolant system.

I discovered this by troubleshooting where water was moving and where it wasn't. I just put it in the water, started it and started began off a hose for a few seconds seeing if water was moving then put it back on and then move on to the next. When I discovered the water was never making it to the top of the heads I plugged the pee hole on the back of the boat that leads out after the valve assembly. When I did this the engine built up pressure and water moved through the heads also keeping the temperature down.

I am going to take the valve body assembly apart again and see what's going on. Either the thermostats are stuck open (they are brand new) or the grommets holding the plugs/springs have give way and are allowing water to flow through the valve assembly at all times despite water temperature.

 

[tmfeaster]

Re: OMC Crossflow v4 115hp Turbojet - Overheated/Ignition and Head Problems

Discovered the grommets busted allowing the valve and spring to come off, thermostats are fine. I should have replaced these when I first had it apart.

I have new gaskets, valves and grommets on the way. Should have it fully fixed by this weekend!!

 

[ScorpionRage]

Re: OMC Crossflow v4 115hp Turbojet - Overheated/Ignition and Head Problems

Feaster! I read that you replaced the fuel pump. I am currently having a problem with my rage15 turbojet 115 where it would idle fine then shut off. The same for wot. I can see just the smallest trickle flowing into the clear filter. I just replaced the fuel filter and countless other things. I can see just the smallest trickle flowing into the clear filter. If you could please share your fuel pump configuration with me it would be appreciated. I am having a hard time parting with 400$ to replace with a factory pump.

 

[ScorpionRage]

Re: OMC Crossflow v4 115hp Turbojet - Overheated/Ignition and Head Problems

Allow me to take a moment and explain all that I have completed. Dropped a rebuilt engine due to original throwing a rod. New starter, burned up from too many attempts to start. New Battery, it was time. New coils spark plugs and power pack. New gas squeezy bulb with fuel filter. Also I redid the wiring harness due to questionable power. Disconnected the oil reservoir because I was unsure whether or not it was actually mixing; I mix my own fuel at the pump. I removed the grommets and thermostats because i was having some heating issues; I experienced better outcome in temp without the flow restriction. Anything else?

 

[tmfeaster]

Re: OMC Crossflow v4 115hp Turbojet - Overheated/Ignition and Head Problems

Feaster! I read that you replaced the fuel pump. I am currently having a problem with my rage15 turbojet 115 where it would idle fine then shut off. The same for wot. I can see just the smallest trickle flowing into the clear filter. I just replaced the fuel filter and countless other things. I can see just the smallest trickle flowing into the clear filter. If you could please share your fuel pump configuration with me it would be appreciated. I am having a hard time parting with 400$ to replace with a factory pump.

Do you have the factory fuel pump setup? Have you checked to make sure your gas tank is venting?

My setup was not done by me, but seems simple. It is a simple automotive carb 4-7psi electric fuel pump pulling from the tank and injecting into the block directly within the port that the old pump hooked too. I will try and take some pictures for you. There is another article on here somewhere with a guy who gave instructions and pictures on how he did it.

 

[tmfeaster]

Re: OMC Crossflow v4 115hp Turbojet - Overheated/Ignition and Head Problems

Allow me to take a moment and explain all that I have completed. Dropped a rebuilt engine due to original throwing a rod. New starter, burned up from too many attempts to start. New Battery, it was time. New coils spark plugs and power pack. New gas squeezy bulb with fuel filter. Also I redid the wiring harness due to questionable power. Disconnected the oil reservoir because I was unsure whether or not it was actually mixing; I mix my own fuel at the pump. I removed the grommets and thermostats because i was having some heating issues; I experienced better outcome in temp without the flow restriction. Anything else?

I mix my own oil too, I have heard too many problems out of the oil pump.

If you are getting water flow, your PSI is staying up and your engine stays cool then it sounds like you replaced what you needed.

If you still have other problems, it sounds like it is dying at WOT and idle from your other post. You have to determine if it is fuel or electrical. Once it does do you still get good spark on all 4 plugs?

If no, start testing the stator, regulator/rectifier and all wiring.

Do you have the service manual? It is a must have!

 

[tmfeaster]

Re: OMC Crossflow v4 115hp Turbojet - Overheated/Ignition and Head Problems

I got the valve assembly put back together and back on the engine without a problem. Took it to the lake this weekend and had much better PSI and the engine heads were around 190 deg F after 30 minutes of WOT, still too hot right? The engine water pressure still never got to 20psi...so I checked for more leaks.

I saw water dripping pretty steady from below the muffler under the adapter plate. So, I will now be replacing the gasket between the muffler and adapter plate. I should have the gasket tomorrow so I will work on that this week and try it again this weekend. Updates will come soon.

 

[emoney]

Re: OMC Crossflow v4 115hp Turbojet - Overheated/Ignition and Head Problems

I know my 140 Crossflow has plastic water diverter jackets that can go bad. Something to look at in your manual, anyway, because I'm not familiar with your motor. You've been very patient though, so I know you'll get to the bottom of it, and finally there'll be nothing left to cause a problem...knock on wood.

 

[ScorpionRage]

Re: OMC Crossflow v4 115hp Turbojet - Overheated/Ignition and Head Problems

Feaster, I sorry for my delay in response. As to your issue with the water leaking around the muffler, it should not much to do with the heating problem but the removal of the engine is much easier to replace that particular gasket because if I recall there are 5 bolts to remove 3 of which are not too bad but the other two, they are too near the stern wall making it nearly impossible to remove and re-torque. Also from my experience with automotive engines, spray down every gasket with spray copper. I know that most gasket are impregnated with a sealer but the spray copper gives you that extra umph.

 

[ScorpionRage]

Re: OMC Crossflow v4 115hp Turbojet - Overheated/Ignition and Head Problems

Okay now my issue. I dont believe it is any type of electrical, it has got to be fuel. I would really like to replace the existing fuel pump with an auto fuel pump, the only problem is that i have a small line going into one side of the carb and a larger going into the other side of the carb. Also, I have a similar smaller line coming from cylinder 4 with a pulse limiter. I do not have any type of manual. I am always too skeptic to buy one because I am concerned about the detail. If your time allows, would you be able send me the ISBN of your book and to take some detailed pics of your fuel system, I would be much obliged. Also, take the time and replace the Y water lines coming from your heads. Be sure to use HIGH temp hose;that is very important, and remove that plastic T where they meet with a brass T. Another thing to look at is the water jackets. It is about $5 each for a new gasket and is worth opening them up when your find crystallized salt or even a stupid lodged snail.

 

[tmfeaster]

Re: OMC Crossflow v4 115hp Turbojet - Overheated/Ignition and Head Problems

I know my 140 Crossflow has plastic water diverter jackets that can go bad. Something to look at in your manual, anyway, because I'm not familiar with your motor. You've been very patient though, so I know you'll get to the bottom of it, and finally there'll be nothing left to cause a problem...knock on wood.

There are water diversion tubes in the heads, I checked those already and they are OK. Thanks for the kind words!

 

[tmfeaster]

Re: OMC Crossflow v4 115hp Turbojet - Overheated/Ignition and Head Problems

Feaster, I sorry for my delay in response. As to your issue with the water leaking around the muffler, it should not much to do with the heating problem but the removal of the engine is much easier to replace that particular gasket because if I recall there are 5 bolts to remove 3 of which are not too bad but the other two, they are too near the stern wall making it nearly impossible to remove and re-torque. Also from my experience with automotive engines, spray down every gasket with spray copper. I know that most gasket are impregnated with a sealer but the spray copper gives you that extra umph.

Actually that leak can make a big difference, if there is a leak the engine will not build up high enough water pressure to maintain the propper cooling on the engine. I already took the muffler off without taking the engine out. I just took out the divider wall that the primer solenoid was once mounted on and got to it pretty easy. I get the gasket today and I will put it back together. I have been using the gasket sealant called out in the service manual on gaskets it asks me to put it on.

 

[tmfeaster]

Re: OMC Crossflow v4 115hp Turbojet - Overheated/Ignition and Head Problems

Okay now my issue. I dont believe it is any type of electrical, it has got to be fuel. I would really like to replace the existing fuel pump with an auto fuel pump, the only problem is that i have a small line going into one side of the carb and a larger going into the other side of the carb. Also, I have a similar smaller line coming from cylinder 4 with a pulse limiter. I do not have any type of manual. I am always too skeptic to buy one because I am concerned about the detail. If your time allows, would you be able send me the ISBN of your book and to take some detailed pics of your fuel system, I would be much obliged. Also, take the time and replace the Y water lines coming from your heads. Be sure to use HIGH temp hose;that is very important, and remove that plastic T where they meet with a brass T. Another thing to look at is the water jackets. It is about $5 each for a new gasket and is worth opening them up when your find crystallized salt or even a stupid lodged snail.

The manual has a good amount of detail and is worth the money. I would not have done what I have done without it. I have replaced ALL water line hoses, including the Y's above the heads you call out, I have also replaced the water jacket gaskets already.

Here is a good thread on how to convert to an electric fuel pump. Mine was already converted but my pump went bad so I had to replace it. I have the exact same pump as called out in this thread.

http://forums.iboats.com/showthread.php?t=408984

 

[tmfeaster]

Re: OMC Crossflow v4 115hp Turbojet - Overheated/Ignition and Head Problems

Wow, I feel like an idiot right now. The little water dripping from below the muffler, yeah that wasn't it. Still dripping, but why? The grommet at the back of the transom which the steering cable goes through is busted a bit and water is getting in and dribbling down.

So why am I losing water pressure? One thing I never checked and one thing the flushing kit doesn't push water through......the pressure relief ball/spring in the jet pump.

That's right folks, it was clogged open with leafs and small wood debris, most likely from the first good time I ran it on the river after fixing everything. At that time I had water pressure, after I didn't.

So that explains it, get that fixed, put it back on the water and I bet it builds up pressure!

 

[tmfeaster]

Re: OMC Crossflow v4 115hp Turbojet - Overheated/Ignition and Head Problems

Went out on the water this past weekend expecting no problems (still can't get my tach to work though) and it started over heating!!!! So I get to the Marina and start checking everything I could think of.

The back exit pee hole was plugged with some type of hard mud clogging it. Unplugged it and everything started to seem fine! Then, it started over heating at idle, and at full speed was OK. It was not moving enough water at idle and based on the IR Thermometer the top of the engine was much hotter than the bottom. So come to find out, the deflectors in the heads had finally broke apart... I never replaced them after the first big overheat.

This labor day weekend is my last weekend for this boat, run or fail! Thursday and Friday I will be taking the heads off, replacing the gaskets again and putting in the new deflectors.

I also found out why the Tach isn't working. My battery in the boat died on me which made me find this error. The wires coming from the stator had been rubbed raw from the flywheel! They had slipped out of the holding clip... so this explains why the tach and battery charging still aren't working. I will also be putting in a new stator!!

Hopefully this is the end for real this time. I have replaced everything that water passes through now!

 

[AlTn]

Re: OMC Crossflow v4 115hp Turbojet - Overheated/Ignition and Head Problems

that motor has had less than "stellar" healthcare in the past....persistence is paying off, tm...that counts for something, right?

 

[tmfeaster]

Re: OMC Crossflow v4 115hp Turbojet - Overheated/Ignition and Head Problems

It does! Next year I should have a good "peace of mind" knowing I have replaced most of the engine with new parts and I actually can take care of it better than it was by the previous owner!!

Tonight the work begins for this repair. I will let you know! Everyone keep your fingers crossed! I have had this boat since June, it has been on the water almost every weekend but with only two successful runs and I think I just got luck on those runs!!

 

[tmfeaster]

Re: OMC Crossflow v4 115hp Turbojet - Overheated/Ignition and Head Problems

Well I put in the new defelctors and it helped the PSI and engine temp very little. The water PSI at full throttle is around 4-6 PSI now and will actually hold less than 1 PSI at idle rather than 0.

With an IR Thermometer the engine gets to about 209 degress on the left head and 188 on the right. Still too hot.

Any ideas? The only gasksets I haven't replaced are the adapter plate gaskets.

I have flushed it like crazy, replaced the head gaskets, head cover gaskets, thermostats, valves, grommets, valve body assembly gaskets, exhaust manifold gaskets and many hoses but not all.

I just can't figure out where and why I am losing water pressure.

 

[apollothesun]

Re: OMC Crossflow v4 115hp Turbojet - Overheated/Ignition and Head Problems

sorry if i missed it but did you change the water impeller in the lower unit? did you check the housing
and the gasket? did you blow compressed air from the lower unit end water pipe up to the block
and see if you feel the air at the heads?

 

[tmfeaster]

Re: OMC Crossflow v4 115hp Turbojet - Overheated/Ignition and Head Problems

sorry if i missed it but did you change the water impeller in the lower unit? did you check the housing
and the gasket? did you blow compressed air from the lower unit end water pipe up to the block
and see if you feel the air at the heads?

Thank you for your reply but this is not mounted to a lower unit, it is mounted to a jet drive which does not have an impeller. The jet drive is designed to take in water for coolant which is why there is no real gearing, direct drive.. the prop always spins even in "neutral".

I haven't done compressed air. I have flushed it with the water kit and water makes it all the way through the engine and out the back pee holes but it just doesn't build up enough pressure to fill up the engine completely and cool it efficiently.