Still to warm, The conclusion

[1975FA]

How do the plugs look?Even a 4 stroke can run hot if too lean on fuel.

The plugs had a nice tan look to them.

 

[1975FA]

I got the head back from the machine shop last friday. They took .004 off it to get it flat again. The machinist said it was low on the exaust side. This is aparenty comon with overheated yamaha heads. The gaskets came in the mail saturday. It took about 5 hours to pull the engine and take the head off and 10 hours to put everything back together. The gods of camshaft timing smiled a me and the engine runs great. I finished it last night and rode it to work today. I have about 40 miles on it with no signs of overheating. With winter coming to a close I gotta get some miles on.

 

[SRXSRULE2]

So I guess this is an addition to the chapter of the book on head gaskets? I have seen this before on a diesel truck where the cylinder pressures are higher then what the nitro engine would have. The slightest nick in the gasket was causing the coolant to boil.

 

[1975FA]

So I guess this is an addition to the chapter of the book on head gaskets? I have seen this before on a diesel truck where the cylinder pressures are higher then what the nitro engine would have. The slightest nick in the gasket was causing the coolant to boil.

yea and in this case the coolant didn't take on the grayish color or the exaust odor. The coolant tank was never oily and scumy. I noticed when I was putting it back together the velcro strips on the top of the radiator cover where a previous owner had a programer mounted, add that to the leaking water pump seal and this engine was very hot before I bought it.

 

[09nytro]

Well that's good ...so far so good...I hope its fixed sounds like it is
I was thinking about you today and was going to pm you to see what you fig. out