560XP Crank Bearings

[njm]

merely curios.

 

But the autotune will mask an air leak in the crank case ect ect , this is why most failed motors are scrap , on a carb saw you would pick up the change in the motor at the start of any problem , autotune adjusts the mixture until it can no more and the saw will run to destruction ,

Edited January 18, 2015 by njm

[Macpherson]

But the autotune will mask an air leak in the crank case ect ect , this is why most failed motors are scrap , on a carb saw you would pick up the change in the motor at the start of any problem , autotune adjusts the mixture until it can no more and the saw will run to destruction ,

 

Let me shake your hand sir, I totally agree with you. No fuel no oil. When it`s spinning at max rec. speed of 233 times a second which is faster than ever, combined with a claimed " up to 20%" reduction in fuel usage even before the AT compensates for a prob like a dirty air filter is it any wonder that a dried out wee piece of plastic gets roasted. cheers

[SawTroll]

But the autotune will mask an air leak in the crank case ect ect , this is why most failed motors are scrap , on a carb saw you would pick up the change in the motor at the start of any problem , autotune adjusts the mixture until it can no more and the saw will run to destruction ,

 

Likely some truth in that - but it likely saves a lot more saw engines with minor air leaks, than it kills by "masking" them. It is about how observant the operator is....

[Macpherson]

Likely some truth in that - but it likely saves a lot more saw engines with minor air leaks, than it kills by "masking" them. It is about how observant the operator is....

I see your point, but it seems that a lot of these saws aren`t lasting long enough to get minor this or that`s to mask, and the observant operator is being tricked by the AT when the situation becomes critical, at these engine speeds in a lean burn engine, there is really no margin for error.........imo

[SawTroll]

To be fair, I'm 25 and never use the chainbrake either. Just don't touch the sharp bits and you'll be fine 👍😄

 

 

I some times use the chain brake, when starting a saw with a long bar, or drop starting in thick brush - but hit the "trigger" and release it fast after starting the saw.

[spudulike]

Interesing thread, my comments - I use "Simply Bearings" to source come bearings and seals, Chain brake - I only snap it on if I am walking with a running saw or repositioning myself on uneven ground with the saw running.

 

I only snap it on at speed to test it during a service and start the saw with it off - I am an engineer so have some respect for the saw:thumbup:

 

On the bearing wear - could this be down to the saws using less fuel oil mix? Less fuel consumption means less oil is covering the saw internals and during heavy use..........

 

Could the bearing wear be improved with adding a little more oil to the mix? Probably worth trying iMO.

 

I am surprised the flywheel bearing is failing, it is usually the clutch one that gets more abuse from over tightning the chain and extr heat from the clutch.

 

Interesting stuff - perhaps the autotune technology is too good at fuel control and bearing technology has to be looked at to catch up!

[adw]

The nylon cage in the bearing should need less lubricating this was why it was chosen, that and the free running of the bearing, i have not seen many with the flywheel side gone, it is usually clutch side which if you carry on running the saw will destroy the flywheel side, intrestingly enough the cage is quite soft and does not damage the cylinder.

[njm]

The nylon cage in the bearing should need less lubricating this was why it was chosen, that and the free running of the bearing, i have not seen many with the flywheel side gone, it is usually clutch side which if you carry on running the saw will destroy the flywheel side, intrestingly enough the cage is quite soft and does not damage the cylinder.

 

Always flywheel side i have seen fail , saw stops when the flywheel hits the coil most have scores on transfer ports and exhaust due to running lean , the operators i deal with dont wind the chain up solid which i find is the fashion with training these days , this may explain failed bearings on the clutch side ?

[Macpherson]

The nylon cage in the bearing should need less lubricating this was why it was chosen, that and the free running of the bearing, i have not seen many with the flywheel side gone, it is usually clutch side which if you carry on running the saw will destroy the flywheel side, intrestingly enough the cage is quite soft and does not damage the cylinder.

 

Hi adw, I take your point , and would agree with the probable reason for bearing choice, but I have also seen the various ways that they can fail, mainly in motorcycles though.

 

Hi njm ,It would be interesting to know the condition of the cages in the failed bearings ie: worn out, melted, roasted brittle or what ?

 

I wonder if the brake being flung on at speed could be responsible for the transfer of a shock load or kick through the crank delivering a "knock out blow" to the weakest link, the cage. cheers.

[njm]

Hi adw, I take your point , and would agree with the probable reason for bearing choice, but I have also seen the various ways that they can fail, mainly in motorcycles though.

 

Hi njm ,It would be interesting to know the condition of the cages in the failed bearings ie: worn out, melted, roasted brittle or what ?

 

I wonder if the brake being flung on at speed could be responsible for the transfer of a shock load or kick through the crank delivering a "knock out blow" to the weakest link, the cage. cheers.

 

Just a strip of flattened plastic , no heat damage and still flex in the remains of the cage , old school operators chain break is not abused .