speedysprocket
Alex
- Location
- Chesapeake, VA
So a new guy here brought his wife's 1992 Kawi 750 over tonight because the pipe was getting hot and melting couplers. And after leaving tonight, it's still hot.
About the boat- 750, single cooling line, PJS pipe, PJS head, no water box, the rest appears stock.
Cooling is coming from the pump to the bottom of the exhaust manifold. Water then comes out two fitting in the head. One is going to the head pipe, the other over the side. The other side of the head pipe then goes over the side. There's a t-fitting to supply the stinger, and I tried it on the line coming straight off the head, and the line coming off the head pipe. I tried a flow control valve in both configurations too to limit water to the stinger. No change. And before all this, I verified the pipe wasn't clogged and the water jet inside the head pipe flows freely.
Compression was 140 and 150 psi. Took the head off and found in the cylinder the little pieces of aluminum that are laying on the head in the second picture. These were in the water jacket and we have no idea where they came from. Head gasket is copper and looked fair. Took the aluminum out and ran it, still hot. I checked the carbs before he left, too, and nothing looked bad or clogged in there.
The owner said one week the engine ran fine, a week or two later it started melting couplers. What else can we check for? This has even me perplexed.
Thanks!
About the boat- 750, single cooling line, PJS pipe, PJS head, no water box, the rest appears stock.
Cooling is coming from the pump to the bottom of the exhaust manifold. Water then comes out two fitting in the head. One is going to the head pipe, the other over the side. The other side of the head pipe then goes over the side. There's a t-fitting to supply the stinger, and I tried it on the line coming straight off the head, and the line coming off the head pipe. I tried a flow control valve in both configurations too to limit water to the stinger. No change. And before all this, I verified the pipe wasn't clogged and the water jet inside the head pipe flows freely.
Compression was 140 and 150 psi. Took the head off and found in the cylinder the little pieces of aluminum that are laying on the head in the second picture. These were in the water jacket and we have no idea where they came from. Head gasket is copper and looked fair. Took the aluminum out and ran it, still hot. I checked the carbs before he left, too, and nothing looked bad or clogged in there.
The owner said one week the engine ran fine, a week or two later it started melting couplers. What else can we check for? This has even me perplexed.
Thanks!
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