Worn out Decompression Valve

[Burnham]

My MS261 has one. I use it. Electric start would be sweet.

I think that "roll starting" is easier on the shoulders. Its where you rest the bar on the log (nose obviously clear of kickback hazards), and you push with the pistol grip, while pulling the starter cord.

It's a good starting method, one called for as SOP by D.D. Dent...but it doesn't work worth a toot on smaller saws ime. The saw has to carry some fairly serious mass to not get jerked sideways by the pull against it's compression, for the maneuver to be controllable and safe.

Of course, this never was an issue for Sir Doug . If you weren't running at least an 066, you barely needed to show up for his classes.

I used it when under his eye, but not otherwise. I prefer a foot in the lower handle, a stiff arm/strong hand on the upper handle...what Dent used to say was like "a monkey f**king a football". Or maybe that was the "standing upright, lower handle in your crotch, one hand on the upper handle, other hand pulling" method that he describe thusly . Perhaps he referred to my preferred method as "thought up by some weak-assed piece of shit", as I think more on it .

His abilities at derisive language will seldom be matched . He was one of a kind.

 

[SeanKroll]

With smaller saws, a crotch on a downed branch or a brush pile. If on a log, a small saw will sometime land sideways, so plan properly, and do it safely.

A point well made, B. Thanks for mentioning.

 

[stig]

I drop start everything .
But then I hardly run anything over a 30" bar.

 

[Al Smith]

IMO most of the time the seals go bad ,get hardened .Could be from old age,ethanol in the gas,grit building up on the outside,who knows .
Could be other things too .Carb set too lean,plugged or restrictive exhaust which will cook the exhaust side of the piston .Not enough oil in the mix doesn't help things .Torn intake boot (Stihl) .
The dead give away on seals might go like this .You fire up the saw,runs great for about 5 minutes then seems to lean out only to get worse the longer it runs .After it cools down it again runs okay for a short time .

 

[Magnus]

I'd like to install one on my 066. Need another cover, or I'll just cut a hole.

Any concern with the plug on the cylinder? Loctite on? Soft threads?

Its not just to drill and tap a 10mm hole straight in cylinder wall. Hole to chamber were decompression valve sit in cylinder is 1-1,5mm. If its bigger flame can get in and create heat.
It takes a bit practice and very good drills to do this right. Not all you can do it on even if it looks possible.

 

[mike in pa]

My MS261 has one. I use it. Electric start would be sweet.

I think that "roll starting" is easier on the shoulders. Its where you rest the bar on the log (nose obviously clear of kickback hazards), and you push with the pistol grip, while pulling the starter cord.

Remember the old hand crank start mowers? We could go that route.

 

[Nutball]

Our 660 almost won't start with the decomp valve pressed, so it's one of few I don't use.

 

[Raj]

Its not just to drill and tap a 10mm hole straight in cylinder wall. Hole to chamber were decompression valve sit in cylinder is 1-1,5mm. If its bigger flame can get in and create heat.
It takes a bit practice and very good drills to do this right. Not all you can do it on even if it looks possible.

Crap I missed this. The cylinder on my 066 has a threaded hole already with a plug in it. Are the plugs loctite in?

 

[mike in pa]

On a serious note. When did they start putting decompression valves on chain saws? I still have my dads 1970 Homelite C72 and that 80cc motor needed a decompression valve.

 

[MasterBlaster]

In 1971.

 

[Nutball]

I know the Husqvarna 2100 didn't have one right? I'll guess they switched mid 80's since I think the 3 series came out early 90's or late 80's, another guess.

 

[Magnus]

Crap I missed this. The cylinder on my 066 has a threaded hole already with a plug in it. Are the plugs loctite in?

No, there is a tension washer I think.

On a serious note. When did they start putting decompression valves on chain saws? I still have my dads 1970 Homelite C72 and that 80cc motor needed a decompression valve.

The Sweden made Companion MS1 had decompression valve in late 50's. Many saws with larger engines had them before this.
1916 The Sector saw was made and it had valves to open and give it a little schnapps before cranking as well as release a bit pressure.

 

[Magnus]

The technolegy has been there all the time. The project manager at Husqvarna said he thought it was silly to have a decompression valve on so small engine as the 2100.
He changed his mind after he ran it a couple times he said.
Quote "I promiced the loggers next model should have decomp valve right then and there in the forest".

Its not just the extra part its the handling and use of it that was rather the cause for not having it.
On newer saws with plastic starters its great to use, saves repairs as well as elbow ache on me.
Diagnostic's on a saw with decomp is a lot more fun than without especially after 40+ pulls.

Most Husqvarna saws 50cc+ after '84 could be ordered with or without.

 

[Raj]

My 088 is starting to be hard to start. Press decomp in and when I pull the cord gets ripped out my hand, pulls my shoulder like a MOFO, the handle snaps down and wacks my other hand, and doesn't start.

The hunt is on for a valve in my area. Hope that's what it is. Real bad when it's cold. Can I clean it up?

 

[SeanKroll]

Pull out until pawls engage, then yank.


Its a machine. Do you need to maintain anything? Why is is hard to start?

 

[pete mctree]

My 088 is starting to be hard to start. Press decomp in and when I pull the cord gets ripped out my hand, pulls my shoulder like a MOFO, the handle snaps down and wacks my other hand, and doesn't start.

The hunt is on for a valve in my area. Hope that's what it is. Real bad when it's cold. Can I clean it up?

It is always worth checking the gap on the coil. If they move they can make a saw a nightmare to try & start.

 

[Raj]

Coil is gapped correctly, now. I did have that issue before.

Sean, seems like the valve closes too quick, then rips the handle out of my hand. I did find a new valve, a dealer in Simcoe removed it from new 880.

 

[SeanKroll]

I know the pull/ jerk you mean.

Rescue saw starter handle or homemade starter handle.
Might even use a stopper knot to keep from rewinding into housing, with another knot for the handle. Could be a knot forming an eye. Removable handle could hook the eye, if the handle is in the way while milling.

Would only consider a removable handle for this application.

088 has to be tough no matter what.
I think the 880 i used has a decomp valve.

 

[Raj]

I picked up a D handle, just in case.

 

[SeanKroll]

Can't you fab an electric start that will grab the flywheel nut through a custom opening?

 

[Raj]

I'd like that!

 

[SeanKroll]

Your shoulder will like that.

The rotational speed isn't that high, is it?
Might need a one-way freewheel, like a ratchet, or grind a socket somehow to sit release.

Maybe 088 shoulda had a kick-starter.

 

[SkwerI]

The compression release is on the top of the saw. If you hold the saw properly with your left hand on the top handle while starting, you can easily extend your thumb and use it to hold down the compression release. The problem is that it closes too soon. If you hold it with your thumb while starting it won't close until the saw fires off. No more dislocated shoulder.

 

[Raj]

I was thinking of doing that but my hands were too beat up at the time.

 

[Al Smith]

Speaking about shoulder .Because of nearly a life time of working with my arms above my head I've developed shoulder problems .Strange as it seems about 3-4 weeks ago I wrenched my left shoulder from starting of all things a Stihl 200T .SOB talk about hurt .
I was just in an akward position in a tree trying to start the damned thing with it about shoulder lever . It's getting better .I just have to remember I'm not 30 years old any more .