Pistons - fried like an egg!

[spudulike]

ok guys, the saw gets what the saw needs, i'd be happy with the stock items fitting either, is it worth getting done soon or waiting for the problem to show itself with poor running? it runs sweet at the mo. Ed

 

It is a simple one - if your saw has 150 psi compression or over then it is good. If it is under that then a new piston will probably bring it back in to order, inspection of the plating will decide if the cylinder/jug needs replacing.

 

The only exception I have found to this has been an old vintage Poulan Countervibe that ran at 130PSI and this is generally where a normally running saw of this manufacture sits - many owners on Arboristsite.com verified this.

 

175psi on a newish saw is normal

[burrell_]

Baileys thats who i was looking at big bore kit im going to pressure check the crank and see if its worth the kit and i may as well port it to

[armchairarborist]

in that case i'd better check the compression and the plating. thanks man, i might be able to lay my hands on a compression testing device tomorrow:thumbup1:

[spudulike]

in that case i'd better check the compression and the plating. thanks man, i might be able to lay my hands on a compression testing device tomorrow:thumbup1:

 

I use a gunson one, gives sensible readings that work for me i.e. new saw - 175psi, older saw - 150psi and fubared saw - 100 - 130psi:thumbup:

 

Poor mans compression check, raise the saw and let it drop holding on to the start handle - 10 - 15 seconds fall is good - 3 seconds and you have a buggered saw:thumbdown:

[Old WoodChip]

Nice collection, which is sure to grow.

Do you think the fuel these days has got a shorter shelf life than pre lead free stuff (like when it was 35p per gallon)

For all you young uns, thats just under 5 litres!!!!!!!!!!

[elfinwood saws]

Any big bore kit has to be purchased complete - the original bores on saws built mid 70s onwards have plated bores with Chrome being on the older saws and Nikasil on the newer ones - only cast iron liners can be bored out.

 

Some of the US guys do big bore kits - Baileys are one of the companys but they charge $$$$$ for delivery to the UK!

 

Cost of fitting a P&C kit (customer supplied) - around £75 and will include a pressure check and tach tune to the carb.

 

£75 how much an hour is that?

[spudulike]

Around £25 - £30, I have just done a couple of saws recently - one had a dealer fitted seal that was turned inside out when the cases were split and a new P&C were fitted and had then seized and the other a split impulse line that took out the piston.

 

Many people can throw a P&C on a saw but few make sure the saw is set up right and the route cause is found and resolved.

 

What would you charge for similar?

[spudulike]

Oh - and invariably I do a lot more on top and don't charge - like give the saw a good clean and check the carb over including a rebuild - but you know the score, it is rare where you do one particular job without doing three more!

[MattyF]

:thumbup:Spud does a top job, I had given up hope of finding a decent saw mechanic they either have it for months then charge the price of a new saw or say it's unfixable.. He's currently fixing a load of broken bolts and other bits on my 372 that my dealer said would be impossible to fix so I might as well buy the 441 on the shelf! The 357 I gave him a month ago now starts first pull and runs sweet... Worth every penny!

[TimberCutterDartmoor]

pressure checking the engine

 

Can you elaborate on this? I have a nice old saw that I suspect the crank seals have failed on... it goes like billio but when coming off the revs tries to die at the bottom and splutters before hand. Carb was tuned recently...

 

Air leak - same thing? Ta.