Chainsaw Reed Valves

[stinkbait]

Has anyone experimented with the reeds on a reed valve chainsaw. I have several chainsaws with reed valves. I was wondering if anyone has made carbon fiber or fiberglass reeds to replace old spring steel reeds in a chainsaw. I read that different tension reeds give different powerbands in a 2-stroke engine and that spring steel reeds are old technology because they loose their spring tension over time.

 

[Honkie]

Hey Stinky!

I have gone as far as trim the reeds until they barely seal agianst the the carb spacer. I noticed a little, LITTLE, bit of improvement. I would think carbon fiber or fiberglass would be harmed by the effects of gas, but I might be wrong. I would also be afraid they would break and score the intake side of the piston.


Kris

 

[stinkbait]

Carbon fiber is what all the dirt bike and atv racers use. That's why I asked. A broken carbon fiber or fiberglass reed would do less damage than a broken steel one. I think I might buy some carbon fiber reeds for a atv or dirtbike and cut them to the shape and sizes that will fit my Super XL-925 and see if it makes a difference. From what I have read the lower tension, or LT, reeds are good for low end torque. The stiffer the reeds the higher your max hp is moved up the rpm scale. For max power at high rpms you would want high tension, or HT, reeds. I was just wondering if anyone has ever experimented with this on a chainsaw.

 

[teacherman]

What are some good examples of reed valve saws? The only one I know of from the relatively modern era is the 009-012 series, with a recommended max rpm of 9.5-10.5K.

 

[Tzed250]

The SP125 came with fiber reeds...

 

[ozflea]

Reed valves have been around for years on chainsaws and Karts Mac's use them don't use the steel ones as when digested they do terrible things Kart engine's use pheonic or fibreglass reeds with far better results.

Mc Bob

 

[stinkbait]

What are some good examples of reed valve saws? The only one I know of from the relatively modern era is the 009-012 series, with a recommended max rpm of 9.5-10.5K.

homelite zip, super xl, 925, mcculloch sp/cp125, etc. There are a lot reed valve saws.

 

[stinkbait]

Reed valves have been around for years on chainsaws and Karts Mac's use them don't use the steel ones as when digested they do terrible things Kart engine's use pheonic or fibreglass reeds with far better results.

Mc Bob

The ones in my SP125 aren't metal. I think all my other saws with reed valves have steel ones. Have you heard of someone replacing steel ones with fiberglass or carbon fiber in a chainsaw?

 

[Bill G]

All my kart intakes have fiber reeds. Here is a Gem V-12 for a Mac

Bill

 

[aaronharrison827]

Does anybody know about these McCullough Reed valves there's three plates they're all different thicknesses and I don't know which way they face it's an old vintage chop saw can send pics of the valves and the saw if need be

 

[Bill G]

You are having a heck of a time

 

[rngrchad]

Does anybody know about these McCullough Reed valves there's three plates they're all different thicknesses and I don't know which way they face it's an old vintage chop saw can send pics of the valves and the saw if need be

You have the block the reed and a piece of bent looking metal. The reed is sandwiched between the block(prolly plastic}and the bent metal. Ideally if held up to the light you don’t want to see a gap between the reed and the cage.

 

[heimannm]

May 2009 -------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------> November 2023

 

[rngrchad]

May 2009 -------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------> November 2023

Get lost mate. I replied to a current post.

 

[heimannm]

My apologies if I offended you, but Mitchell hasn't been active for many years, and McBob has passed away.

If someone is looking for information on McCulloch saws the McCulloch Chain Saws thread in the Chainsaw Stickies section will be more helpful.

https://www.arboristsite.com/threads/mcculloch-chain-saws.71126/page-2434#post-8115344
There is no plastic reed plate on the 795 based cut off saw.

Mark

 

[hwrdpromac7900]

When did McBob pass?

 

[heimannm]

I don't remember exactly, I am going to say 4 or 5 years ago?

Mark

 

[aaronharrison827]

You have the block the reed and a piece of bent looking metal. The reed is sandwiched between the block(prolly plastic}and the bent metal. Ideally if held up to the light you don’t want to see a gap between the reed and the cage.

You have the block the reed and a piece of bent looking metal. The reed is sandwiched between the block(prolly plastic}and the bent metal. Ideally if held up to the light you don’t want to see a gap between the reed and the

 

[aaronharrison827]

These are pics of my saw I don't have any serial numbers or anything I don't know what it is I was just hoping somebody could help me assemble these Reed valves

 

[heimannm]

That is a Partner based saw, not a McCulloch. You might have better success posting your questions in the Partner thread in the Chainsaw Stickies section.

https://www.arboristsite.com/threads/partner-chainsaw-thread.170206/
Mark