GL1200 overheating

[dan filipi]

So I should see a difference by removing the crankcase breather tube right?

 

[mcgovern61]

Possibly, but not guaranteed. You may actually notice an increase in pressure at the crankcase breather tube when the engine heats up, but again, the crankcase has a little pressure all of the time.

I will try to remember how to find this kind of leak. On tugboats it was easy to tell when there was a crack in the block because we could see the water level increase in the expansion tank sight glass when the engines are throttled up. (And of course we would eventually see exhaust and oil in the water).

 

[dan filipi]

Before changing the head gaskets there was exhaust residue and a very small amount of oily like residue in the reservoir.

 

[mcgovern61]

Before changing the head gaskets there was exhaust residue and a very small amount of oily like residue in the reservoir.

I'm no expert, but I think we are getting close and it isn't looking good. :crying:

I'm hoping some of the trained mechanics can step up and offer their opinions. (That includes you backyard mechanics that have skills that would put some professionals to shame!)

 

[dan filipi]

Something not right about getting the same result in the tester on both sides.

I keep thinking maybe there's an exhaust passage common to both sides of the engine, some sort of PCV system or air pump but the engine has nothing like this other than the crank vent line that goes to the air filter. :Awe:

 

[joedrum]

Wow mcgovern on the scent trail. dan maybe you could get it hot enough to get the crack open with the thermostat out , shut it down and pressureize some stop hi quality stop leak in there while the crack is still open this might seal it up. probably some ludicrous thinking

 

[socrace]

I've found that using Block Chek can be tricky stuff sometimes.
It uses a chemical called bromothymol blue that turns yellow when exposed to carbon dioxide. It is super sensitive, a person's breath is enough to change it.
So there is the possibility where exhaust fumes in the garage can get sucked in, (maybe through the coolant reservoir vent in this case?) and that can be enough to affect the test results.

 

[dan filipi]

I've found that using Block Chek can be tricky stuff sometimes.
It uses a chemical called bromothymol blue that turns yellow when exposed to carbon dioxide. It is super sensitive, a person's breath is enough to change it.
So there is the possibility where exhaust fumes in the garage can get sucked in, (maybe through the coolant reservoir vent in this case?) and that can be enough to affect the test results.

Oh interesting, I blew into the reservoir with my mouth thinking I would clear exhaust out. Maybe it was sensing my breath eh?
Test was done outside by the way.

 

[joedrum]

this is one of those deals thats hard on a guy. its got to the point that you just have to figure it out. i've watched the video and the water is not moving. either the pump is not moving water or its getting enough resistance to nullify the pump. its not the pump if its new. i saw on roady thread pump drive to pump some sort of slot drive thing. i wonder what turns that. its hard for me to believe that the exhaust gas is causing the pump not to circulate at all. but i've been wrong many times about things. especially since the water was not moving when the thermostat was out and the cap not on but i guess it could deprime the pump somehow. it would have to prove it to me. sometimes when a motor gets real hot from a stuck thermostat and then opens putting cold water rite in the pump it can crack there close to the pump causing it to take on air at the pump. this happened to me on a big farm tractor. this is especially true on something that's sat a long time without running. i'm not a fan for thermostats all tractors,combines and trucks lost their thermostats. the possibilities are many on what might be wrong but youve gone this far. it took me a while to figure out what happened to my tractor.

 

[AApple]

That's true...even if there was a crack in the block/heads somewhere, it wouldn't keep the pump from pumping...I'm still believing there is a problem with the H2O circulation system...
If you DO happen to find a crack, or bad heaad, or whatever, and fix it, chances are it's gonna happen again if ya don't get some movement in the coolant... :heat:

 

[dan filipi]

With all the rain here I havent had any chance to do anything on it.

Sunny and 60's today and tomorrow so today I let everything dry out and get out there monyana.

Concidering I could have gotten false results with the Block Chek I'm going to back up and check the pump flow again and maybe do a comparison with mine.
One step at a time I guess.

 

[dan filipi]

mcgovern61 (Gerry) and I talked for almost 2 hours yesterday.

Suspecting a coolant flow problem we figured to check the block temp at each cylinder and the flow of coolant thru to each side coming out the head fitting. Here's the result.

Head/block temps were virtually identical during warm up and stayed that way while running for about 20 minutes.
With the head fittings removed, bike on center stand and a garden hose filling at the radiator neck, flow was very close to even although it did seem to flow a slight more out the left side but so close I think it's not an indication of a problem.
The radiator would take the full flow of a garden hose as the water came out both heads.

Ok, so I'm getting confused here so I have to back up to square one.
I made a few video's while the engine is warming up.

This one is engine cold:

[video]https://www.youtube.com/watch?v=qQM-y8jS7EI[/video]

This one is with the engine temp close to where the tstat would start to open.
I had just filled the system from empty with water so the bubbles that come out would "normally" be expected as air is purged:

[video]https://www.youtube.com/watch?v=bThcjmfKwDw[/video]

This one is alittle bit warmer, tstat open more, then appearing to close as it should when the coolant level rises some:

[video]https://www.youtube.com/watch?v=lgPEkItsRxI[/video]

This is another only slightly warmer:

[video]https://www.youtube.com/watch?v=aV3F8IPJvCo[/video]

Now temp is a bit below mid gauge when it boils out with what appears to be alot of bubbles.

[video]https://www.youtube.com/watch?v=XcbfOh0OAaA[/video]


After watching these videos what should I do next?

 

[socrace]

The fan looks like it's off in the videos, needs to be forced on all the time if the cap is off. Maybe it is on, hard to tell.
The '83 still had mechanical and vacuum advance, right? Maybe check it out with a timing light.

 

[joedrum]

the videos show no signs of continuous water flow, i know i sound like a broken record but. my next step would be to take the thermostat out. then there would be no mechanical obstruction in the system. you might be able to put right back on without new gaskit and then do your test again. looking for signs of continuous water flow though the system. i would do mcgovern61 test on pump flow with the starter right after taking out the thermostat and before hooking everthing back up to to check for pump flow. maybe even run it like that keeping radiator full with hose. be nice to have good piece clear hose to hook up to it to divert the mess. if the motor is putting air in the system you sure should be able to see it there, if the pump is pumping or not you would be able to see it there. thats what i'd do

 

[mcgovern61]

Dan, we are back to the same thing with the video. Bubbles not really showing up until it gets hot and then spitting pretty good. I am still leaning on a crack that opens when the block gets hot.

You mentioned that the right head was off. I know you checked the heads while they were off, but did you check the block for a flat even surface? There seems to be enough evidence that the engine overheated significantly at some point. I would be curious to see if you ran the exhaust gas test again without breathing into the tank first to see the results.

 

[dan filipi]

Yes I checked the block deck for flat when the heads were off.
I havent done the exhaust gas test again yet.

Just trying everything I come up with before writing off the engine as cracked.

I'm considering all the suggestions and some ideas I get from other forums as well as the owner who talks to friends for ideas.
One she talked to said he had a 1200 which always ran hot.
Turned out it had a air pocket which wouldnt purge until they removed one of the head coolant fittings, after that the temp was fine.
That got me to thinking ( a dangerous thing anymore) to measure the amount of water that goes in after emptying the radiator and block from the drain plug.
Real strange, The capacity is 3.4 quarts but it will only take 2 quarts into the radiator including a few burps then top off.
When I fill mine it takes approx 3.5 quarts including the recovery so I put one quart in the recovery on the 1200 and let it cool figuring as it cools that quart will get sucked in.
Well, it's cool now and the recovery has dropped only a small amount, maybe a cup and the radiator is full :?: The way I figure it, all the water should have been sucked in and wanting more to top off the recovery.
I tested the recovery hose is making a tight seal and the radiator cap is new.

Maybe I'm chasing my tail at this point but it seems like there's something not right here, that and the fact the radiator gets hot well before the thermostat would be opening, after just a minute or 2 running.
Maybe a cracked cylinder sleeve would cause these symptoms?

 

[dan filipi]

Say Gerry, you know alot about pumps.
Is it possible for this type pump to pump in the reverse even though it's turning in the correct direction?

If that were the case it could explain the radiator getting hot right away as well as sucking air causing cavitation.

 

[joedrum]

yaeh it like you said the water heats up quickly like somthing else is heating it up. if you took all the plugs out and did gerrys pump check with the starter this sould eliminate exhast gas and most pressure, if the pump operates like gerrys video then theres probably nothing wong with the pump. then this sould tell you that it has a severe crack or something.

 

[AApple]

...Is it possible for this type pump to pump in the reverse even though it's turning in the correct direction?

The pump itself can't pump in reverse unless it's spinning backwards. However...IF the impeller is made wrong, or is the incorrect configuration, it simply won't do anything but stir the coolant around the impeller.
Certain automotive pumps work in a reverse rotation from "normal"(late model V8 Chevies, for example). If a pump that is designed for an earlier model engine is installed on a late engine, the pump will just spin, but not produce any flow. The same is true if a later style pump is installed on an earlier engine.
I'm assuming the impellers on your spares, and the one on the engine now have the same shape/design? :headscratch:

A bubble, or air pocket could cause an overheat situation, but I can't see that causing the pump to not flow anything... :head bang:

 

[mcgovern61]

Say Gerry, you know alot about pumps.
Is it possible for this type pump to pump in the reverse even though it's turning in the correct direction?

If that were the case it could explain the radiator getting hot right away as well as sucking air causing cavitation.

The impeller would have to be a reverse vane to pump backwards when the pump is turning the right way. Of course, my assumption is that you have verified that it is turning the right way.

We had a firepump on a tug running at 50 psi when it should have been at a minimal 75 psi. Ran that way for 8 years and no one bothered to find out why. I got onboard and did not accept the pressure and found out the rotation was backwards (3 phase wired out of phase). Changed the wiring and corrected the rotation and it pumped up to 120 psi! Point is, it ran backwards for years, pumped water but ran hot at the housing because the impeller was cavitating significantly.

I would think that it would be unlikely that the pump is running backwards because that would assume Honda changed the rotation on the 1200 from the 1100. However, a wrong impeller on a replacement pump is very common.