# Yamaha 15 2 stroke



## blondmonkey777 (Oct 18, 2012)

used to have that same motor and it is one of the best motors ever had mine new put over 3000 hours on it beat it to hell with hittin ground and whatnot still ran perfect the day I sold it and its still running.


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## DblHaul (Nov 27, 2008)

Shadowcast777 - I think they're good motors too. I got this one to replace one that I bought new in 2000 but was stolen. I'm hoping I can get this one fixed up.


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## CurtisWright (May 9, 2012)

Be very very careful breaking the head bolts loose. They can easily break off in the case. If they are stiff, work them in and out until they come out easily. Dont try to muscle them out. 

I broke on off in my 25 Yami


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## Creek Runner (Sep 1, 2011)

> Be very very careful breaking the head bolts loose.  They can easily break off in the case.  If they are stiff, work them in and out until they come out easily.  Dont try to muscle them out.
> 
> I broke on off in my 25 Yami


^ Nothing a little Blue Wrench can't handle!


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## Frank_Sebastian (Oct 15, 2007)

Hi Creek Runner,

I live in Sebastian and my family and I keep our boats on lifts, so we seldom flush them. I want to know where to get "Blue Wrench" and is it a tool or penetrating oil.

Thanks and best regards,
Frank_S

PS I am used to working with a torch in one hand and a wrench in the other, but don't enjoy it.
Frank


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## Brett (Jul 16, 2008)

I grew up with 2 "blue wrenches", often used consecutively 










and the other


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## Creek Runner (Sep 1, 2011)

The latter is the one! Sorry frank wasn't referring to a product, talking about a torch.


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## DuckNut (Apr 3, 2009)

Frank- and everyone else
A mixture of 50% ATF (auto trans fluid) and 50% acetone is the best penetrating lube you can get.

Look around on machinist forums and you will find the same.


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## cutrunner (Jun 8, 2010)

Brett thats a plasma torch lol.


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## Brett (Jul 16, 2008)

> thats a plasma torch lol












Not quite CR, look closely.
It's just an oxy-acetylene cutting torch.
Plasma torch has a high voltage power cable
and a different head










I can afford oxy-acetylene, but not a plasma setup.


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## DblHaul (Nov 27, 2008)

I finally had time to remove the head. The head bolts came off easily (might be a first!) It was not pretty.









The passage circled in yellow was completely blocked by white corrosion. In this picture I had already scraped some of it off.










Heat damage on head:









Blocked passage on the head as well:









I've got a new head and gasket on order - not even going to try and clean this up. This motor runs well except for a rough idle...


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