break-in

[dajogejr]

another good tip is when you install your pistons just manually turn your flywheel a bunch of times and manualy seat the rings then do your heat cycles. I think it was on NitroTate on HQ that mentioned it on his banshee rebuild video as well.

 

I would stop listening to anyone that said turning a motor over by hand can seat rings.....

 

You need the motor running, and the force of the explosion to push the rings outward to seat.

Not to mention, you keep doing that...it'll scrape the oil off the cylinders, then it's metal on metal.

 

Top and lower ends of two stroke rely 100% on their fuel to get lubrication.... that's why if you start a methanol bike on ether (cold weather, etc.) do NOT rev it up until it's been running for a few seconds.

 

Let it get some methanol/oil into the motor first....

 

I warm it up once or twice, warm it up and go for a quick ride shifting through the gears to make sure everything is tight, etc.

 

Then warm it up and beat the piss out of it.

[mopar1rules]

I would stop listening to anyone that said turning a motor over by hand can seat rings.....

...lol...that's what i was thinking. i was going to just keep quiet, but then i couldn't hold it in any longer.....lol. :biggrin:

...hopefully this guy can do my porting and head work too....lol :biggrin:

You need the motor running, and the force of the explosion to push the rings outward to seat.

Not to mention, you keep doing that...it'll scrape the oil off the cylinders, then it's metal on metal.

yeppers.

Edited October 19, 2008 by mopar1rules

[deckheight]

I do a little different variation of the heat cycle thing already mentioned... Quick warm up then ride 5 minutes constantly varying rpm below 1/2 throttle, cool down. Second 10 minutes varying rpm below 3/4 throttle w/very, short full throttle bursts, cool down. Third 20 minutes below 3/4 throttle with more frequent and longer full throttle bursts and a couple max rpm bursts, cool down. Break in complete.

Need a couple minutes of varying low rpm operation to lap the the fresh hone, piston and rings, especially with tighter piston clearances and/or higher compressions (first cycle). Also need to bring it up to max rpm a few times during the initial break in (third cycle) if you ever expect to see those rpm's again in the future. IMHO anyway.