Reed effects on engine character

[totty79]

Do aftermarket reeds have a noticeable effect around idle rpm? Smoothness and stall resistance.

Which are best in this area? Boyesen Power or Carbon Tech? I'd expect the two piece Power reeds to be best for this but don't have experience of either.

I've recently removed a flywheel weight, and find it much better in many ways but less smooth near idle and easier to stall. Not a big issue but if a reed change helps then it seems worth it.

[timp]

In 30 years I have never found it necessary to swop reed valves.

[dan williams]

In 33 years I have. The carbon reeds are stronger than the stock fiberglass reeds so they can be made thinner and more resilient. That means they open and close faster which holds more charge in the crankcase which improves power delivery off idle. I can pull a gear higher with the VForce reeds than with stock. I bought two sets of the CarbonTech when I thought I couldn’t get the VForce for my new bike but I found the VForce reed block for an older  KTM65 fit the Beta if you swap the petals so I didn’t try the CarbonTechs yet. They’re just sitting there gathering dust.

So yeah, the first mod I do to any new bike is carbon fiber reeds. Love ‘em!

Edited May 1, 2018 by dan williams

[totty79]

I'll take another look at the thread on Vforce KTM65 reeds. 

Boyesen look to be cheaper and easier to source though so I'm interested in any experience anyone can share on these, especially a comparison of the two types.

 

 

 

[pschrauber]

Have Boyesen CarbonTech mounted now the second set.

They work fine but should be looked through every 20h for wear and mini cracks which can occur at the base and at the ends. Beside that I can't blame them for anything bad, they give a crisp response and you can even hear them when they hit the red cage in lower rev the engine not under load.

Edited May 1, 2018 by pschrauber

[perce]

Some time ago we did a back to back test with 2x 290 sherco, one standard & one with boysen reeds. The bike with boysens had far too much go for our rocky & slippery beck sections.

[totty79]

Thanks for the replies, but it's hard to tell from the descriptions if I'd like a reed change or not, I might just have to try a set.

What I hoped a reed change would provide is more predictable chugging and stall resistance. Thats the one bit of riding where I liked the flywheel weight. I can deal with it with the clutch, it's not a problem just a preference. A minor increase in liveliness is ok as a trade off but not what I'm seeking.

[jimmyl]

Bit of a random thought but maybe refit your flywheel weight to bring the bottom end back to how you like it as reading above the reed swap may give you the zip off the bottom end you where looking for by taking of the flywheel weight

[totty79]

I like your thinking.

I didn't like the overrun with the flywheel weight either though.

Now pretty much decided to try the reeds then decide which compromise/combo to make.

Still undecided on which ones to go for though.

[carlos]

I put the carbon tech reeds in my 2017 Factory Evo, didn't notice much difference. I did notice a stronger, quicker pull when i went to a #50 pilot (from the stock #48)  I have just ordered the V351B V-force reeds from Moto-Tassineri, (with the softer 3P412M reeds installed) they will be here on Friday. Give me a week or so to install and evaluate them. Please note the 2017 Factory 250 Evo has a VERY soft powerband, my buddies stock 2016 250 Evo pulls much stronger than my bike.

[totty79]

Mines a 2012 250, not sure how it compares to other years.

[peterh]

I have fitted boyesen dual stage reeds to 2010 Evo 125, a 2012 Evo 200 and my 2014 and 2015 Jotagas 250. I haven't used the carbon reeds so cannot compare. Once jetting is optimised (and yes had optimised settings of the carbys with standard reeds before i decided to change), i have found that on all 4 bikes that, in my opinion, there is better stable idle and off idle, an improvement in ability to pull smoothly from low down but also a crisper response throughout the range. By reading the boyesen material the dual stage suit my riding. I dont do splat walls that maybe the carbon reeds would give better top end  but i relish the smooth, slow climb, turn and then double blips up and over logs, rocks etc. I think the bike that benefitted by the boyesen reeds most noticeably was the Evo 125, it seemed to give the 125 a lot more low down pull and smooth uptake rather than just have to rev the 125. I admit that with the 2015 jotagas i also changed the dellorto to a oko 26mm and a 5mm inlet manifold spacer at the same time as putting in the boyesens, so cannot be sure what the single effect of the boyesens were on that bike.

[totty79]

That's also my style of riding.

Out of interest was the jetting change consistent across all bikes? (e.g. 1 step on the pilot) or did you need to go through the full circuit by circuit tunning prices each time? 

[retromlc]

Why don't to mill some off the flywheel weight, take 1/2 oz off and try it, keep going till you get where you want, no cost involved, if you have a milling machine 

[carlos]

Got the Vforce reeds the other day, says v351C right on the box, 28mm round opening in the throat. Must say, they look like something Tamiya or Revell would make (cheap plastic!). Had to trim one piece of plastic off to fit, and of course the rubber pieces out off the manifold. Tried it in the driveway, seems nice and smooth, pulls real nice wheelies. Will get to try them out for real on Sunday.