Spuds Porting and Tuning Thread

[spudulike]

You taking any off the base of the cylinder or are the aftermarket pistons taller?

 

I need to reassemble it with the gasket in place, measure the squish and then decide what material to remove from the cylinder base and piston outer crown.

 

I am pretty sure the aftermarket piston will be the same dims as the OEM part give or take half a thou but fitting and checking it will sort that out.

 

Just a case of reassembling the saw and measuring again after the work is done - Martin has a fine end result..................second time round.........sorry Martin:001_rolleyes:

[spudulike]

I have now checked the squish with the base gasket missing and the saw turns over but the piston kisses the squish band so the squish is almost the same as the base gasket thickness - around 0.5mm as standard. This test is prior to cutting the pop up metal and gives a standard squish measurement

 

In short, this means the depth of metal taken from the outer peripherals of the piston must match the amount taken from the base of the cylinder.

 

0.75mm or 0.030" sounds about right and Burrell will hopefully do this for me next weekend!

[Eddy_t]

Christ! It's a slow process, I thought I'd took my time!

[TIMON]

Hi Spud,

We've got a Stihl 441 that is very lacklustre. Is this something you could work on? It's about 5 years old.

Thanks

[spudulike]

Christ! It's a slow process, I thought I'd took my time!

 

Normal turn around is a week, two max! You have to understand this is our mate Matty, I get a cylinder, muffler and piston, he then wants a pop up and sends the bottom end so the job changes from a port and return to a port, lathe work, rebuild and return. Then I receive a new piston ring and circlip and have no confidence all the saw is in that box!

 

We all love Matty and he is a good bloke but his saws always leave a little....sorry, A LOT to be desired. The chain brake handle is off the machine and God alone knows if the parts are all there.

 

I have been fitting this work in around all the other jobs I have coming in hence the time it has been taking and it is a bit of a Shyte or bust job so have no idea where it will end up.

 

Unfortunately I put these sort of jobs in second place to normal servicing on machines that are needed immediately, Burrell (Martin) has been kind enough to spend his time on it as well and it will then take time to find all the parts and reassemble/test!

 

My own 066 has been 1.5 years waiting - still not got the ignition timing spot on to date! 20 degrees adds up to 3HP down on top end!

[Eddy_t]

Normal turn around is a week, two max! You have to understand this is our mate Matty, I get a cylinder, muffler and piston, he then wants a pop up and sends the bottom end so the job changes from a port and return to a port, lathe work, rebuild and return. Then I receive a new piston ring and circlip and have no confidence all the saw is in that box!

 

 

 

We all love Matty and he is a good bloke but his saws always leave a little....sorry, A LOT to be desired. The chain brake handle is off the machine and God alone knows if the parts are all there.

 

 

 

I have been fitting this work in around all the other jobs I have coming in hence the time it has been taking and it is a bit of a Shyte or bust job so have no idea where it will end up.

 

 

 

Unfortunately I put these sort of jobs in second place to normal servicing on machines that are needed immediately, Burrell (Martin) has been kind enough to spend his time on it as well and it will then take time to find all the parts and reassemble/test!

 

 

 

My own 066 has been 1.5 years waiting - still not got the ignition timing spot on to date! 20 degrees adds up to 3HP down on top end!

 

 

I hope matty is reading this and shipping a delicatessen your way then! He hasn't sent the short block?

[spudulike]

Hi Spud,

We've got a Stihl 441 that is very lacklustre. Is this something you could work on? It's about 5 years old.

Thanks

 

Is it "lacklustre" due to it needing a good service or it just isn't that exciting to use?

 

I have a bit of an issue with tuning these saws as the ring end on one of the piston rings runs very close to the exhaust port and this will snag if you widen the port and this is one of the main methods of tuning a saw.

 

It is also a Strato saw so there is little to change on the inlet port width as well!

 

You can always make lots of small changes and end up with significant improvement but without doubt on this saw, the simplest method to get gains would be a muffler mod - that is as long as the saw is running as it should and compression is up to scratch!

[TIMON]

In short... A bit of both. I think the piston and barrel are ok. We had a couple of scoring casualties on older saws so we've switched to motomix or aspen. Thinking of a muffler mod and a good service then. What area are you and would it be ok to send it to you?. (I'll confirm the piston is ok first) we're in Birmingham South .

[spudulike]

In short... A bit of both. I think the piston and barrel are ok. We had a couple of scoring casualties on older saws so we've switched to motomix or aspen. Thinking of a muffler mod and a good service then. What area are you and would it be ok to send it to you?. (I'll confirm the piston is ok first) we're in Birmingham South .

 

I am in North Hertfordshire in the Baldock/Letchworth area, sending it in via courier is fine - one thing to make you aware is that if the saw is given to employees then please understand that their welfare and safety are your responsibility and if there is an accident.........you may find yourself with issues if the saw has been modified.

 

Most of the work I do is for guys personal saws and most find picking up a 60cc saw that cuts as fast as a 90cc saw on a similar bar has much less negative effect on the body.

 

The choice is always the owners and I do what is requested and always raise this as a point to consider.

 

Check the saw over - modifying a saw should be done on a healthy saw and isn't a way of enhancing a saw with running issues!

[MattyF]

Ha ha thanks Steve , it should all be there mate I left the chain brake off the bolts are on the case and internals are in place also left the handle off for access but it's all in the box I even pressed in the handle bolts and a little note on the bit of card to show what's what ..I have every bit of confidence it's all there

Your right eddy probably owe him a few treats !!