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Top End rebuild question

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I live in IL and its still freezing and still have about a foot of snow on the ground.

I pulled the bike into the basement so I could work in warmth while doing the winter projects.

My question is on the top end build, how important is it to start the bike right away after rebuilding the top end?  I've never done it during the winter and I can't start it in the basement......so just wondering about the lubrication aspect of it if I put it together now but can't start it for a couple weeks?

Any advice from the seasoned guys??

I'm not talking about breaking it in, I'm not worried about that.  If I lube everything up good with 2T oil I'm thinking it should be ok with a few stroke of the kickstarter.

 

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It will be fine to let it sit. You will have more lube on the piston/ cylinder/ rod bearing then it would if it sat for a few weeks after a race/ ride.

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Sure you can start it in the basement..! You just run a hose from the exhaust out the closest window..! Haha

What you just did is no different then a bike being built in Japan, and then being shipped to warehouses. then to dealers, then gets assembled, then sits until it's sold...

It will be fine..

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 If I lube everything up good with 2T oil I'm thinking it should be ok with a few stroke of the kickstarter.

 

Lubing a new piston/rings with oil is a good way to end up with a blowby problem.

 

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please explain why.

 

Oiling the piston/rings greatly increases the chances of glazing the cylinder wall on a fresh top end. Heat cycling a fresh engine is almost as bad, and if you do both, you almost always end up with poor ring seal.

 

A dry top end build is the way to go, but if that blows your mind, don't use anything thicker than WD40. Only use 2-stroke oil on the wrist pin and bearing.

Edited by CamP
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Oiling the piston/rings greatly increases the chances of glazing the cylinder wall on a fresh top end. Heat cycling a fresh engine is almost as bad, and if you do both, you almost always end up with poor ring seal.

 

A dry top end build is the way to go, but if that blows your mind, don't use anything thicker than WD40. Only use 2-stroke oil on the wrist pin and bearing.

Don't agree with this at all.

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Old habits die hard. The dry top end build was developed by multi-time AMA superbike champion engine builder and former Team Honda Manager, Udo Gietl. He spent over $150k testing it, as well as many other cutting edge engine developments, on the dyno in the 70's. It may seem counter-intuitive, but it works.

 

Every pro road racing mechanic/tuner/team manager that's been around for any length of time knows who Udo Gietl is.

Edited by CamP
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to oil or not to oil, that is the question ;)  I heard from a very well respected engine builder in the auto performance industry that all you need is WD40 on the piston and cylinder walls and so that is what I do.  It may not work for everyone but it works for me.

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This discussion sure is raising some eyebrows.. I have to say, I have always oiled the parts during a rebuild, and have never heard of the dry break-in until I started reading these forums. I gotta say,it sounds down right crazy and abusive to beat up on a brand new piston and ring that I just spent $150 on,

 

but then again, I didn't spend $150,000 testing it either, and would never look at that piston again until the end of the season... I am always up to learn something new

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The only place that you should be oiling when assembling a top end, is a little bit on the wrist pin and bearing. The piston, rings and cylinder walls should all be dry. The oil that is in the gas is all a 2t needs upon break in. It's ALL about getting the rings to seat properly to the cylinder wall.

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