Spuds Porting and Tuning Thread

[spudulike]

RIP 560 . What do you recon caused tat ten Steve ? Bad casting ?

 

The stuffers are thin pressed metal, the saw was split and then put together again and it looks like there is a bit of gasket in the bottom of the crankcase that may have abraded the surface of he stuffer until it wore through and caught up.

 

I am not sure if the gasket just didn't mate properly or a thin bit broke and entered the case or what but it has caused some bad damage - it is very unusual to have stuffers break up like this. A big shame as it was a chance to see how the autotune responded to porting:thumbdown:

[Stubby]

How restrictive does the saw look in standard form Steve ?

[spudulike]

How restrictive does the saw look in standard form Steve ?

 

The muffler is mega restricted, there is a plate right in front of the port with three holes in it. The exhaust will come out and hit this taking the volume down significantly but it will also reduce the flow in the same way. The outlet is similar.

 

TBH, I haven't checked the piston skirt, port widths, transfer design etc. I am sure there are things that can be done:thumbup:

[Stubby]

:001_smile:Ok Steve. I know mine has had the muffler modded ( its loud ) Would be interested in getting the rest done .......

[MattyF]

Ok mate send us a bill and I will have a box of spares, shame It felt like a top end seize... Really gutted.

[spudulike]

Ok mate send us a bill and I will have a box of spares, shame It felt like a top end seize... Really gutted.

 

No bill Matty, just the courier back.....call it a favour and will be glad to see you if you come back down here.

 

Changing the subject, got the timing light on the 066, looks like 20-25 deg advance on what should be 27-32 deg so reckon we are around 5 deg out and that is enough to make the saw pretty boggy. Got a new aftermarket coil on order, hope it has the built in advance and will then check and set the ignition once fitted!

[Joe Newton]

So I was hoping to get a 372 to get ported to run on a 20" bar. Trouble is I'm stuck buying second hand and I don't want a saw who's history I don't know.

 

Been offered a 441 in tidy nick for a decent price. Is there much that can be done to these? I know you fiddled with a 460 recently. What did you manage to do?

 

The original owner had drilled a rough hole in the muffler, I'll want that sorted for sure. Not a patch on your brazen foghorns!

[spudulike]

So I was hoping to get a 372 to get ported to run on a 20" bar. Trouble is I'm stuck buying second hand and I don't want a saw who's history I don't know.

 

Been offered a 441 in tidy nick for a decent price. Is there much that can be done to these? I know you fiddled with a 460 recently. What did you manage to do?

 

The original owner had drilled a rough hole in the muffler, I'll want that sorted for sure. Not a patch on your brazen foghorns!

 

The 441 is difficult, the ring end runs down the side of the exhaust port stopping any widening!

The 460 has lots of small modifications rather than one big one, the blow down is the largest one but it gives good increases. Daythetrees was the fella I did it for.

[spudulike]

Been out with my 357 that I recently revisited, Blimey it goes a bit now. Really lent on it on 12" elm and it just kept pulling. Very impressed:thumbup:

[Joe Newton]

The 441 is difficult, the ring end runs down the side of the exhaust port stopping any widening!

 

The 460 has lots of small modifications rather than one big one, the blow down is the largest one but it gives good increases. Daythetrees was the fella I did it for.

 

 

So basically just a muffler mod?

 

Basically it has to be louder. If the saw cuts faster as a result I suppose that's okay too