Fast Eddie
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Any of you clever folk know what this chap has sticking out of his head...?
What's stuck in his head...?
- Thread starter Fast Eddie
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Decompression valve as per chainsaw. Push valve in to lose say 30% of compression, kick the bike over and on first firing the pressure from the flame front pushes the valve shut and engine fires on next stroke with full compression, just been working on a scheme to add it as I an under doctors orders never to exert myself again under pain of death. I was going to add it to an insert under an extended plug so no head machining needed.
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Re: CR stuck in his head
I question it's actual ability to effectively relieve that much air on a, ?375cc? or more, cylinder. :?:
I've seen many of these compression release....I have 32 chainsaws. small sample here:
http://www.arboristsite.com/community/gallery/authors/dynodave.76135/
Only a few have a CR on them (111cc & 70cc). Even my 114cc, 2 bad azz 100cc, 95cc, 84cc, 72cc saws don't have a CR. The saws are not that hard to start (if CR is not activated) but I wonder if their use is to reduce stress on the starter mechanism?
I question it's actual ability to effectively relieve that much air on a, ?375cc? or more, cylinder. :?:
I've seen many of these compression release....I have 32 chainsaws. small sample here:
http://www.arboristsite.com/community/gallery/authors/dynodave.76135/
Only a few have a CR on them (111cc & 70cc). Even my 114cc, 2 bad azz 100cc, 95cc, 84cc, 72cc saws don't have a CR. The saws are not that hard to start (if CR is not activated) but I wonder if their use is to reduce stress on the starter mechanism?
Deets55
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Re: CR stuck in his head
Dave,
I have a single cyl. 350 cc Yamaha quad with a pull start. No way will you get that to start with out the release. I forgot it set it one day and lifted the quad off of two wheels when I tried to start it. It didn't do my arm much good either. Not the same as a kick start but the release does reduce the amount of effort required.
dynodave said:
Dave,
I have a single cyl. 350 cc Yamaha quad with a pull start. No way will you get that to start with out the release. I forgot it set it one day and lifted the quad off of two wheels when I tried to start it. It didn't do my arm much good either. Not the same as a kick start but the release does reduce the amount of effort required.
o0norton0o
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Almost certainly it's a compression release. Two of my milling chainsaws that have them on their cylinder heads. (stihl .090's) I use them to mill trees into useable lumber. Every now and then some big gorrilla type person would come by the log dump while we were milling a log and one of us would ask him to pull start a saw. (*but not tell him about the compression release) Without using the release button, the saw would rip the pull starter handle right out of the guy's hand when he tried to start it, leaving him holding a hand full of strained fingers. I guess we were a cruel bunch of guys...
No doubt that a compression release would extend the life of a bike's electric starter or a rider's right knee...
No doubt that a compression release would extend the life of a bike's electric starter or a rider's right knee...
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Re: CR stuck in his head
1. 90% of them were free...picked out of town transfer stations by friends or given by ex-owner
2. diagnose the problem and often the fix was under $10 for even $400-$1600 saws
3. excellent education in troubeshooting technique of 2 stroke ignition/carburation
4. more than one saw is good, if you climb a tree with a 7 pound saw and you buck 16"-24" oak with a 18-20# brute
like husky 272xp or 2100CD... more saws are better
5. I have a fair amount of big wood on my property to clean up
6. You need junk ones for lending out to friends...if they don't come back, or they kill it,
it doesn't matter :mrgreen:
CAD= chainsaw acquisition diseasetoppy said:
1. 90% of them were free...picked out of town transfer stations by friends or given by ex-owner
2. diagnose the problem and often the fix was under $10 for even $400-$1600 saws
3. excellent education in troubeshooting technique of 2 stroke ignition/carburation
4. more than one saw is good, if you climb a tree with a 7 pound saw and you buck 16"-24" oak with a 18-20# brute
like husky 272xp or 2100CD... more saws are better
5. I have a fair amount of big wood on my property to clean up
6. You need junk ones for lending out to friends...if they don't come back, or they kill it,
it doesn't matter :mrgreen:
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Re: CR stuck in his head
I used to cut firewood for a living. I have a chainsaw with a Mac 91 racing go cart motor - it ate all my other chainsaws for breakfast.
Back on subject - My old BSA 441 had a compression release lever that lifted the ex valve a hair of its seat to aid starting. It came stock that way but it got yanked along with every other disposable gram of weight in the interest of winning dirt races (WAY BACK).
toppy said:
I used to cut firewood for a living. I have a chainsaw with a Mac 91 racing go cart motor - it ate all my other chainsaws for breakfast.
Back on subject - My old BSA 441 had a compression release lever that lifted the ex valve a hair of its seat to aid starting. It came stock that way but it got yanked along with every other disposable gram of weight in the interest of winning dirt races (WAY BACK).
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