What's on your bench today?

[spudulike]

Just file down the actual  burr, it will be OK, seen it before, not a big issue!

[KWarb17]

1 hour ago, spudulike said:

Just file down the actual  burr, it will be OK, seen it before, not a big issue!

Thanks mate

[Darkslider]

Echo CS-350tes just bought, popped the muffler off for a peek and disappointed to see a fair amount of blow by through the exhaust port.

 

Piston looks clean as a whistle below the top 1/3rd and no scoring or other signs of seizure/wear. For reference I'd say the piston probably looks similar to the bottom photo by Davey Crockett a couple weeks ago, without the scratches.

 

Saw seems to start and run fine, would you crack on and use it like the cheap saw it is or does it need addressing?

[peatff]

If it ain't broke don't fix it. If it's running and cutting crack on.

[Darkslider]

17 minutes ago, peatff said:

If it ain't broke don't fix it. If it's running and cutting crack on.

That was my gut feeling to be honest, just wanted a second opinion from the arbtalk massive first! Seems a well put together saw from the tinkering so far though so don't think doing a pot and piston on it would be too bad if necessary down the road.

[spudulike]

It may just be over use of oil or poor quality oil or/and running rich. Just use 50:1 semi synth oil, clean the piston lightly - it looks in real good shape and then rebuild and tune the top end to within 500rpm of the max revs spec. That should help it out!

[Darkslider]

3 hours ago, spudulike said:

It may just be over use of oil or poor quality oil or/and running rich. Just use 50:1 semi synth oil, clean the piston lightly - it looks in real good shape and then rebuild and tune the top end to within 500rpm of the max revs spec. That should help it out!

The saw doesn't look like it's been cleaned since new and when I took the airbox lid off there was half a forest of compacted mulch in and around the carb/filter, so I'd say all of those are a distinct possibility!

 

The piston in the bottom picture isn't mine, it's Davey Crockett's who posted it a few weeks back in a thread i found when I searched, but the colouration of his piston is almost identical to mine so thought it'd be worth posting up. I haven't stripped the saw any further than removing the muffler and don't fancy taking it to bits completely if I don't absolutely have to 🤣

[spudulike]

You could try running 5L of Aspen through it. The saws I have seen that have had this have purged a lot of carbon out of their cylinders and ports.

Your piston looks pretty good after I enhanced the image, you can see the machining marks on it: -

Is the port completely clear of carbon as it looks to be partially closed?

 

 

Edited January 24, 2021 by spudulike

[Darkslider]

On 24/01/2021 at 12:30, spudulike said:

You could try running 5L of Aspen through it. The saws I have seen that have had this have purged a lot of carbon out of their cylinders and ports.

Your piston looks pretty good after I enhanced the image, you can see the machining marks on it: -

Is the port completely clear of carbon as it looks to be partially closed?

 

 

Yup just had a cautious clean of the port and it's definitely clear, it comes out of the cylinder at a 90 degree angle rather than central and perpendicular if that makes sense. Bottom 2/3 of the piston looks pretty good too like you say machine marks are visible with no scoring. The bore looks like it might have some very fine score marks on the inlet side that I can see but they're uniform and don't look like plating wearing or anything. Hard to take decent photos using a camera phone through such a tiny port.

 

Interesting call on the Aspen, I don't have any but can get some, or I do have a tin of Seafoam additive I could use a bit of. Never tried it in a 2T motor before though has anyone else? 

[Darkslider]

On a related note what tool do you find best for de-coking ports? I've got a mini Dremel with an assortment of attachments that should fit in there, but I'm a bit worried some of the flap disc and wire wheels might be a bit on the abrasive side, I just want to clean it not make a bungled amateur effort at porting 😂