A theoretical question on 2-cycle...

[litefoot]

Let me "ax" you guys a question. Let's say you had limiter caps removed and you held a saw at WOT while continuing to lean out the engine. She starts a screaming and you continue to turn the H screw clockwise. Would the motor starve for fuel first, or would it sieze for lack of lubrication? I'm thinking it would starve first.

 

[Lakeside53]

It will usually starve first, but don't assume you aren't causing damage - it doesn't take much gas to run an unloaded saw real lean/hot/high rpm. A lot will depend on the lube already in the engine, and time is your enemy. Many carbs don't allow you to completely shut off the gas, so it's possible to run them way lean and not have them quit, then they will seize.

 

[lonewolf57]

Thats anyones guess if you ask me.It would depend on how much quality and engineering was put into the engine to start with.I would'nt do it with just any saw,thats for sure.Put a couple new medium grade $600 saws side to side and let 'um rip,WOT,without limiters.It'd be interesting to tear them down and actually see which one held up the best.The internals would show the difference,if any.

lonewolf57

 

[PES+]

They seize

It may take a couple of attempts but they will seize from temp rise running that lean.

Stihl has techs do that as part of training in Virginia Beach (or they did) so techs understand what it takes to lean seize a saw and know that the saws don't fly apart.

I don't know if it is at the Silver or Gold level but it is a good training practice

 

[Fish]

We go out back and burn one here in Ky. at the "Polished Aluminum " level...

No, seriously, they used to seize one up at Bryan's basic tech school in
Cinn, Ohio. lean one out and get it screaming @ 17,500 until it seized, but
that was in the nineties. They do not let me attend the schools anymore.

Too disruptive................ That's what they said anyway.......

 

[husky hustler]

Also depends on exactly how slow you were leaning her out. If you took your sweet time the insides would become one... If you leaned out faster you could have a chance of not having enough fuel to support combustion... But like the above posts said, the damage has been done.

 

[belgian]

Let me "ax" you guys a question. Let's say you had limiter caps removed and you held a saw at WOT while continuing to lean out the engine. She starts a screaming and you continue to turn the H screw clockwise. Would the motor starve for fuel first, or would it sieze for lack of lubrication? I'm thinking it would starve first.

why on earth would you even want to try that procedure? I have plenty of old saws but I cannot get it over my hart to seize one purpose. Maybe I should get one of those green ones and give it a go :hmm3grin2orange:

 

[THALL10326]

It may take a couple of attempts but they will seize from temp rise running that lean.

Stihl has techs do that as part of training in Virginia Beach (or they did) so techs understand what it takes to lean seize a saw and know that the saws don't fly apart.

I don't know if it is at the Silver or Gold level but it is a good training practice

Correct Pest, they do indeed show what it takes to fry a saw by running it lean and long. We had a MS360 down there that we tried frying at 15,500 rpms with no luck, it ran but no power. At 16,000 held in my hand wide open for about 15-30 seconds did the trick just fine, she melted down bigtime. They are using 361's down at the factory now for the melt test by over leaning, over reving. They got one there that has been rebuilt 32 times believe it or not. That old saw had to say why me for sure...

 

[litefoot]

why on earth would you even want to try that procedure? I have plenty of old saws but I cannot get it over my hart to seize one purpose. Maybe I should get one of those green ones and give it a go :hmm3grin2orange:

I'd certainly never do that. Heck, all my saws probably run far richer than they should. I'm too scared to run mine far up on the lean edge. It was a "theoretical" question, but one that even Stihl apparently tries to answer in their training. Anyway, I'm glad to hear from even if your post added nothing to this thread.

 

[PES+]

Almost forgot the original question

In fact with plated bores like all modern saws the piston almost never actually seizes stuck... the ring sticks to the piston and loses enough compression so the saw slows a bit then dies in the old cast iron sleeve engines they used to stick and seize pretty much most of the time

I can count on one hand the number of locked tight seized saws with plated cylinders that I have ever encountered that did not have mechanical cause of seizure from objects wedging the piston stuck

 

[RiverRat2]

Why dont you try it,,, and let us know What happens

Let me "ax" you guys a question. Let's say you had limiter caps removed and you held a saw at WOT while continuing to lean out the engine. She starts a screaming and you continue to turn the H screw clockwise. Would the motor starve for fuel first, or would it sieze for lack of lubrication? I'm thinking it would starve first.

You must be bored!!!!!


opcorn: opcorn: opcorn:

 

[kevlar]

+1

You must be bored!!!!!


opcorn: opcorn: opcorn:

Why!

 

[RiverRat2]

uhh lets see!!!!

Why!

Because I like Popcorn,,,, and I like Beer???????

But not normally together,,,

I was just teasing about leaning the saw out intentionally BTW

 

[belgian]

Anyway, I'm glad to hear from you even if your post added nothing to this thread.

LOL, thanks. I think it's not really possible to add something to your thread as hypothetical questions as yours are nearly impossible to answer.
saw condition, existing wear, temperature, oil quality used, oil mix rate, etc. you name it. No doubt manufacterers will simulate several conditions to optimize their saws, including seizing them. I just don't understand why a regular saw user would be interested in an answer to this question, unless you are a builder, or an EPA fundamentalist caring more about the exhaust gas quality than the saw itself

You could probably also have added a poll question as to how many seconds a given saw would last, perform a real test, and the winner would receive the saw as price, for ex.