Good read on 2 stroke piston seizures.

[jus_me]

Found this on another site but it still relates to the Blaster and all 2 strokes. It is a bit long but a good read none the less..

http://www.dirtbikeworld.net/forum/showthread.php?t=21089

 

[joeak47]

I've read that before, but... A press fit in the bore? Yeah right. I call bullsh#t on that one. In a "press fit" NOTHING MOVES. Now that I think about it, that article sucks.

 

[joeak47]

"
Many people believe that piston seizures occur when engine heat causes the piston to expand larger
than the size of the cylinder bore .... This is not true. If you could freeze your engine "in motion" in the middle of a long full throttle pass, and disassemble it for micrometer measurement, you would find
the piston skirt to measure at a 0.0000 to 0.0005" or so press fit into the bore. That's right, a slight
press fit!" Yeah sure...rolling my eyes

 

[Dutter]

"
Many people believe that piston seizures occur when engine heat causes the piston to expand larger
than the size of the cylinder bore .... This is not true. If you could freeze your engine "in motion" in the middle of a long full throttle pass, and disassemble it for micrometer measurement, you would find
the piston skirt to measure at a 0.0000 to 0.0005" or so press fit into the bore. That's right, a slight
press fit!" Yeah sure...rolling my eyes

Just a little FYI for you, in a water cooled engine the piston can expand faster than the cylinder, I've seen it happen!

 

[Herpderplol]

Just a little FYI for you, in a water cooled engine the piston can expand faster than the cylinder, I've seen it happen!

Cold seize

 

[jus_me]

One thing i cant agree on is 30 seconds warm up !??

 

[joeak47]

Just a little FYI for you, in a water cooled engine the piston can expand faster than the cylinder, I've seen it happen!

I don't understand how you "seen it happen". How did you see it happen? Please explain in detail...
It sure the hell isn't a press fit.

 

[joeak47]

Cold seize

Exactly.

 

[Dutter]

I don't agree with the press fit, but when you start a water cooled 2 stroke when it's -0 and don't let it warm up you will get cold seize

 

[joeak47]

Exactly. That's what I attribute to ignorant operator error. I still hit the deck laughing about the "Press fit " thing.

 

[Blaaster]

Anyone not warming up an engine to operating temperature before giving it hard work is not doing their valued possession any favours!

95% of engine wear happens in the first minutes after a cold start.

Water cooled or air cooled, it is imperative that all expansions are equalised before riding!

I do agree with the snippet on oil migration time and the choice of ratios to prevent starvation.

 

[joeak47]

I do agree with the snippet on oil migration time and the choice of ratios to prevent starvation.

That's about it. Otherwise, in my opinion, it was an article with information that was NOT accurate.

 

[Herpderplol]

I know its a little different on a 4 stroke. but i usually have my bike on high idle until the pipe starts to glow. then lower for a little bit more

 

[Blaaster]

Ideally the engine should be up to the temperature of a heat cycle before riding!