What's on your bench today?

[Sawchip]

Not easy to photograph through the plug hole! I've a new found respect for gynecologists.

 

Top Photo: shows the top of the exhaust port, marks extend from the upper edge of the port to approximately 15mm below the top of the cylinder.

The area of the cylinder visible is no more than 20mm across, so it doesn't look quite so bad in reality.

 

Lower Photo: The closest view I've managed and it appears that the vertical marks lie beneath the cylinder honing.

 

I'm erring towards thinking they are the result of the de-burring process after the ports are milled, but it'd be nice to get an informed opinion.

 

Thanks again:001_smile:

Personally I dont see the problem in taking off the muffler as this would give you a better look at the piston, rings and the port edges themselves. If you have a concern then this is where i would be going.

PS.. if under warranty then dealer first showing them the view down the plug hole.

Edited August 5, 2016 by Sawchip

[spudulike]

They look like witness marks to me, just a surface blemish where the saw has been turned over only. The exhaust port may have some slight rough parts that may cause slight marks like this.

 

Personally I wouldn't worry unless they are still there after 10 tanks but would expect the compression to fall off if they get a lot worse which I don't believe they will.

 

What manufacture is the saw?

[BishBashBosh]

They look like witness marks to me, just a surface blemish where the saw has been turned over only. The exhaust port may have some slight rough parts that may cause slight marks like this.

 

Personally I wouldn't worry unless they are still there after 10 tanks but would expect the compression to fall off if they get a lot worse which I don't believe they will.

 

What manufacture is the saw?

 

It's an Echo 390.

 

I only had a look in the cylinder because I noticed the plug was finger tight whilst checking it over. When I did the close up photo I could see the marks were beneath the honing which eased my concerns.

 

I'll give the cylinder a few of drops of synthetic 2 stroke, expel any excess, and then fire it up. Might give the bore a bit of protection for the first few revolutions!

 

Many thanks for the reply.

[spudulike]

It's an Echo 390.

 

I only had a look in the cylinder because I noticed the plug was finger tight whilst checking it over. When I did the close up photo I could see the marks were beneath the honing which eased my concerns.

 

I'll give the cylinder a few of drops of synthetic 2 stroke, expel any excess, and then fire it up. Might give the bore a bit of protection for the first few revolutions!

 

Many thanks for the reply.

 

On that second photo you can still see the honing marks running through the mark/score so it isn't that deep and reckon it will go with a bit of running.

 

Run the saw hard for short periods and NO half throttle or leaving it on idle for long periods. The saw has a rough bore and rough rings so thrash it and let it bed in quickly before the surfaces polish up.

[BishBashBosh]

Sounds like a plan. 30 second warm up then let it rip

Cheers

[spudulike]

It don't run too well guv, lack of power.......

[spudulike]

I thought this one was a lump of flapjack to go with my coffee......

[Pinkfoot]

Don't suppose it's an 880 being as we're on page 880 ?

[Morgan1936]

Spudulike,

 

A belated big thank you for your advice given many moons ago regarding a scored Husky 350. Did as you said and cleaned up the bore, fitted new piston etc.

Started first pull.

Great advice! Have now got a spare saw.

[spudulike]

Don't suppose it's an 880 being as we're on page 880 ?

 

Sorry, good guess, first one was a MS201 and the second a MS290!