Saw lacking power - Maintainance tip

[18 stoner]

Looking at that muffler Dean it seems a real candidate for sticking a 10mm drill into it a couple of times where the pansey holes are, throwing the deflector away then opening the hi jet a tad:sneaky2:

 

You might end up with a saw that would cut like stock ms240 and wouldnt clog up either!

[Al Smith]

Well you can't expect too much from a saw that has the size engine of a model airplane for one thing . Even less if it were plugged as tight as bulls butt at fly time like that one was .

 

All saws do not do that,none of mine do as a matter of fact and I run 32 to 1 oil mix .

 

To get that much carbon build up the saw would have had to have been set exceptionly rich .

[Mike Hill]

I drilled a hole in the flat peice of Steel between the two bolts.I think it was 8mm in dia.The hole is pretty much inline with the exhaust port.

[Czlowiek Drzewo]

I run a little MS170 as a chipper saw, just lately it's been gradually losing power ( the bit of power they do have) .

 

One thing to check apart from the normal air filter clogging is exhaust clogging. Many saws have spark arrester screens or small apertures behind the deflector plate which, over time clog with carbon.

 

As you can see in the photos, mine was very clogged which was choking the exhaust gas flow.

 

You can wire brush it out but the best way if you have access to it is to heat the carbon with Oxy/acetylene which turns it to dry dust and can be brushed off

 

Before and after photos and now it runs like a new saw.

 

ideal little chipper saw.

 

reall light! Thanks for tip.

[Dean Lofthouse]

All saws do not do that,none of mine do as a matter of fact and I run 32 to 1 oil mix .

 

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I beg to differ Al.

 

Exhaust coke / soot up to some degree, they cannot do anything but, it's just how fast they do it.

 

You have tuned saws so you are seriously telling me that you have never cut into an exhaust that hasn't had deposits of carbon ?????

 

I've been a mechanic for 30 years Al and I've never come across one

[Al Smith]

Sure I'll grant you they will carbon but not that badly .If you want I can pull some mufflers and show some over 30 years old that aren't as bad as those pictures of the little saw in question .

 

In all seriousness I have no idea of the gasoline[petrol ] you folks are using which I suppose could have something to do with it .

 

This is a pic of a Huskie 281 I just worked on .This was taken before I worked on the piston which was starting to burn .

 

I'll put some more pics on after I get home from work today .

[Ian C]

Which part would you "chuck", its a tricky one, I'd chuck the larger of the two parts once separated.

 

:lol::lol: peed meself there huck, Dean why not shove it IN the chipper and get a propper one! i had a go with one once.........jesus.....be better with a bow saw lol

[Mesterh]

Could be carboned up alot if its only used now and then as a chipper/snedding saw, not getting hot enough to burn the carbon off.

 

If replaced a few 020 exhausts over the years that have cracked due to errr misshandling by the groundie every one of them had a fair bit of carbon in.

 

Hmmm with my own logic it would suggest I need to work em a bit more

[Dean Lofthouse]

Depend on the design of the muffler, whether the air filter is cleaned regularly, how often and for how long they are used and whether the mix is lean or rich.

 

MS170 's will carbon up more than others because the paper filter clogs and can't be cleaned as well as a mesh filter.

 

All two stroke pass unburnt oil through he exhaust system, that atomised oil will stick to carbon deposits inside the muffler and if the saw isn't run fast enough or hot enough to burn it away you will get what is shown in the picture, wet carbon.

 

It also doesn't matter whether it's an MS170 or an MS660 they will all do it. It doesn't matter whether you rev the balls off your machine for the next twenty years, at some point the exhaust will coke up

 

I didn't enter into this for an argument, just to pass a tip on, if your muffler seems fine to you ignore this tip, for those of you that for whatever reason your muffler is oiled and coked up, carry out the tip on the first post

[Jonesie]

We get quite a few saws and brushcutters come in for a service like that and as Dean says heating them up soon sorts out the problem. We use a propane gas cylinder with a torch on it works a treat.