ms260 No Compression

[spudulike]

Sounds like the route cause for lack of compression hasn't been found, I usually test for leakage by pressure testing the saw, if you suspect a leaking decomp, washing up liquid and water brushed around the base of the decomp will show it leaking.

 

You could try the washing up solution and then turn the saw over slowly and see if you get bubbles.

 

Typical loss of compression is a seize or semi seized piston, how was the old piston - clean on the exhaust side? How was the cylinder bore - plating in good condition - scored, worn???

 

lack of compression is generally down to seized or worn piston, rings or aluminium transfer on the bore from seizure.

 

If oil (really fuel and oil) is leaking from the decomp - it is probably a sign that the valve is leaking - if you run the saw like this it will either seize or may drop the decomp valve in to the cylinder - both rather unpleasant and expensive.

 

Let us know how you get on

[spudulike]

Sounds like the route cause for lack of compression hasn't been found, I usually test for leakage by pressure testing the saw, if you suspect a leaking decomp, washing up liquid and water brushed around the base of the decomp will show it leaking.

 

You could try the washing up solution and then turn the saw over slowly and see if you get bubbles.

 

Typical loss of compression is a seize or semi seized piston, how was the old piston - clean on the exhaust side? How was the cylinder bore - plating in good condition - scored, worn???

 

lack of compression is generally down to seized or worn piston, rings or aluminium transfer on the bore from seizure.

 

If oil (really fuel and oil) is leaking from the decomp - it is probably a sign that the valve is leaking - if you run the saw like this it will either seize or may drop the decomp valve in to the cylinder - both rather unpleasant and expensive.

 

Let us know how you get on

[Eddie Coyle]

If you change a piston, say for instance a 44mm do you have to put the same size back in or do you have to go a couple of mm bigger? Cheers

[spudulike]

If you change a piston, say for instance a 44mm do you have to put the same size back in or do you have to go a couple of mm bigger? Cheers

 

Forget what you know about fourstrokes with cast iron cylinnder liners and oversize pistons.

 

If you have a 44mm piston in your saw, then you will need a new 44mm piston to replace it, personally I stay clear of Chinese unbranded with their brittle rings, better to fit a Meteor one - very good quality.

 

If the saw has been seized, all that transfered aluminium will need to be taken off the bore and it needs to be 100% smooth - if left on, your saw will run for around 30 seconds!

[Rich2484]

You just need the magic potion to remove the transfer....l

 

Don't ask me what it is I'm sworn under oath not to tell.

[spudulike]

You just need the magic potion to remove the transfer....l

 

Don't ask me what it is I'm sworn under oath not to tell.

 

I use Voldermorts magic wand on mine, the light sabre works if that fails:thumbup:

[Eddie Coyle]

Forget what you know about fourstrokes with cast iron cylinnder liners and oversize pistons.

 

If you have a 44mm piston in your saw, then you will need a new 44mm piston to replace it, personally I stay clear of Chinese unbranded with their brittle rings, better to fit a Meteor one - very good quality.

 

If the saw has been seized, all that transfered aluminium will need to be taken off the bore and it needs to be 100% smooth - if left on, your saw will run for around 30 seconds!

 

Ok cheers mate :-)

[Rich2484]

I use Voldermorts magic wand on mine, the light sabre works if that fails:thumbup:

 

No fair I want one.

 

I was using the missis home made curry. Thought it done a grand job on the loo and it works Wounders on a bore.

 

Now why is my ear hurting.....

[spudulike]

No fair I want one.

 

I was using the missis home made curry. Thought it done a grand job on the loo and it works Wounders on a bore.

 

Now why is my ear hurting.....

 

Sounds like it may be good for cleaning the ring as well:blushing:

[wisewood]

I use Voldermorts magic wand on mine, the light sabre works if that fails:thumbup:

 

A rare shot of spud at work:001_tt2: