just woundering what difference the reeds make to the proformance of the bike, i think that we have a non standard one on at the moment that came with the Keihein carb. all advice is appreciated (needed )

Ihave a gasgas 125 if that helps

Edited February 1, 200620 yr by north_yorkshire_lad

yeh i put some carbon fibre reeds into my sherco290, felt like it gave a more usable bottom end and a bit more pull through into midrange. dunno about boysen reeds but i would expect them to be an improvement on the originals

I put Boysen carbon reeds in a YZ motor once. It did run better than the stock ones, whatever kind of fibre they were. It has to do with them being more stable I think. (either open or closed, no flapping around aimlessly or something to that affect) I'm sure their website will tell you more.

I installed Boysen Reeds in a '97 TXT270 with a very good result. It gave the bike very smooth yet strong power at low rpms. Prior to changing the reeds, the bike had a "hit" where there was a step in power. The step could make the bike difficult to control in tight turns and similar situations. I did not notice any other changes. I used the standard dual stage (power?) reeds. Recently I put a set in a 2.9 sherco with no affect. The original reeds looked just like the Boyseen ones. (I bought th bike used so they may have been changed.)

Boyesens in 4 shercos made everyone better.

Knowledge buries itself into my cranium, that I wanna dig out and share on this topic....

but as I recall from either a brochure or a program, or magazine article in the past, or a very knowledgeable Marine mechanic told me:

Reeds do 2 things. One is they are a one way air valve so that exhaust pressures don't rush back through the carb(s).

2 when an engine is running you can imagine that if we had a little window to see the reeds, you would see that they would appear to "vibrate" open & close and this vibrating action can affect mixture timing to cylinder and I guess change how the particles mix in the gas/air charge (from the carburetor.

as you can imagine fiber based reeds (ala boysen or whomever brand) will claim that the reeds react quicker and easier & more efficiently than stock ones, and I can support the claim somewhat on 3 engines. One a 4 cylinder outboard motor I put them into, and a pair of 321 gasgas txt's I had them in. loved it, I say it smoothed out the engine and yet made it snappy.

but as you would guess, I have to say to some, it is possibly hard to tell on the bikes. Part of the reason is, unless you are a "testing facility" I doubt that you "only" try reeds and not do any other things when you are doing major-but minor engine work...

I know when mine was done there was a tiny bit of grinding (like smoothing the casting) done to the area inside the reed cage and inlet area, plus we did other things too like head base gaskets and some machining on the carb's inlet, and muffler cleaning you know... and who knows, which does more?

But In the 4cylinder Chrysler FORCE 120 outboard, that was the only thing we did to it before test running it, trying to get more performance from the engine, if you know what I mean. the bottom end was a (Noticeably) for hole shots (pulling skiers & or just the boat itself onto plane) but again we had to adjust the carbs, and you know, who knows what was the best part of the job, adjustment or both or reeds?

To me it is like changing the intake manifold on a Small Block Chevy, to an edelbrock one. all by itself might not seem all that noticeable but the other things you typically do when you do it, makes a difference.

Edited February 2, 200620 yr by Sting32