Re: Yamaha Towny

Jack Rutherford /
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> Thomas Davis Wrote:

> -------------------------------------------------------

> I have a QT50 that needs a top end and I was thinking about going the

> ebay niche cylinder route, but there has been a lot of talk on facebook

> about them overheating? What's the secret to keeping them running?

My experience is

1. luck of the draw. You might get one from a batch that is fine. You might get a clunker.

2. I experienced air leaks from the head gasket for sure and maybe the base gasket which indicates that the mating surfaces of the head and jug aren't ideal. It's been awhile but I sanded the head down flat and still had problems. The secret would be identifying and getting rid of all air leaks.

3. If I recall, the ring gap was almost out of spec or out of spec at install (too large). I put the expansion ring in and tried to run it but no luck.

4. I didn't measure it but since the ring gap was out of spec, I assume the piston to cylinder wall clearance was too great as well - which is a huge over-heating issue. And this is probably why, you hear others saying, "I ran that thing pig rich and it still seized up on me." If the rings aren't sealing, you can probably run it as rich as you want and it won't matter.

I returned it despite their return policy stating that the parts must be unused. How are you going to determine whether there's an issue unless you install and run the top end?

I've seen that niche kit for as cheap as $30. Shipping included, right? Allow for some profit and what do these things cost from the factory? less than $10? sometimes you get what you pay for. (edited)

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