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Got this machine for free not running and half taken apart due to what was thought to be a carb issue. I did a compression test and found 60 psi... tore down and found a bad piston head gaskit in so so condition and a pinhole in the radiator. Had the cylinder honed and checked for cracks and then completed the top end rebuild, and a carb clean and rebuild kit and fixed hole in radiator. 125 psi. Ran ok but carb was overflowing like crazy. Tried to adjust float and it still wouldnt stop leaking. New carb , ran good. Ran for 30 mins with idle turned up and then it started blowing coolant out onto the exhaust. Thought it was the head gaskit but when I tore it down again the gaskit didnt look bad. Possibly the hose between the head and lower cylinder area was bad. Changed hose and head gaskit and now it runs like crap. Sound like it is bogging/ very airy sounding if that makes sense. Tried to adjust the carb in every direction with no change. I still have 125 psi compression. Any ideas on what to look for next ?
 

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Crank seal is bad on the water pump side and water pump is leaking into the counter balance gear box - do a complete engine rebuild with all new bearings and seals
 

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Thanks for the reply. If I pull the side cover and access the counter balance gear box and there is coolant that would confirm? If no coolant is present would that still be the problem? I forgot to add in the original post that I did pull off the cover and replace the seals as I wanted to check the water pump and the kit I bought for seals included all.
 

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There is only three ways for coolant to enter the engine; head gasket, water pump and a crack in the cylinder or head. I have never seen or know of another mechanic who had found a cracked head or cylinder that was not caused by another failure (broken piston, rod, rod bearing or something entering through the intake like a rock or hex nut)

Let me know what you find in the counter balance gear box.
 

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Well I'm not sure what to think. Doesnt look to me like water got in but I took some pics to hopefully help. There is a touch of oil on the front of the cylinder by the exhaust but I did premix the gas and ran it with the oil injector for awhile till I knew for sure that injector worked then blocked the line till I had ran all the premix out. 2 strokes arent my forte butI dont know if I'm just over looking something dumb and getting frustrated and making it harder then it should be.
 

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OK - I have to agree that it does not appear that the gear case has had coolant in it (it's one of the best looking gear cases I have ever seen), but what's with the water pump gasket? I've never see a red one. They are usually black or gray.

So you are back to a cylinder or head problem. There is (to the best of my knowledge) only two ways to get coolant into the combustion chamber - from the water pump into the gearcase and then past the crank seal or a defective head, cylinder or head gasket.

If there is another way, please inform me so I can sleep peacefully.
 

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Thanks. The gasket kit I got was a Moose Racing seal kit I got off ebay and thats what color it was.

I agree with you with on ways of coolant to enter the combustion chamber. If I sounded condescending or like I was second guessing you I apologize. I am just frustrated with myself for not being able to figure this out and am not sure I described my thoughts correctly. I apologize for this longer response and repeating the whole story but I will try to clarify my jumbled thoughts below.

I am not 100% positive that I had coolant entering the combustion chamber. I took the pipe off last night and did not see any coolant in there or signs of.

I had the cylinder honed and checked for cracks by a friend who teaches in a machine shop and does a lot of powersport motors. I also had him clean the head and check it. He said it looked good to go. So new piston, rings, gaskets, and rebuilt the carb. When I ran the machine after rebuild it ran ok but not great. I tried to adjust the carb but I couldnt seem to get it set right and it was overflowing very bad. I tried to adjust the float but that didnt help. After messing with it for quite awhile I had enough and ordered a new carb. Installed and got it running good.

I had it running for about a 30 mins then saw that there was more than normal "smoke" coming from the machine and saw that I had coolant coming out of the front area around the exhaust. There was enough coolant and smoke from the exhaust I can not say for sure where exactly it was from and I assumed the head gasket blew out. I changed the gasket with the one I had out of the Moose kit as I used the one that came with the piston kit. At this time I also noticed the hose between the head and the water pump housing was in poor condition, so I changed that as well. After thinking about it, it is possible the the hose was blowing coolant up towards the head and onto the exhaust and I assumed it was the head gasket.

Got everything put back together and got it running again. But now it sounded very throaty(airy). I tried to adjust the carb with no change. I checked compression again and still have around 125psi. Coolant was still at the top of the radiator and the overflow tank is at the appropriate level.

Once again thank you very much for the replies and advice. Also again sorry for the long reply and making myself out to be a moron but the more frustrated I get the worse it gets. I hope that helps clarify and you got an idea of what to look for next so I can just get this thing to an enjoyable machine.
 

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I'm just disappointed it was not the WP - it is the most common problem and mostly unseen because of the design.
 
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