V-Force 3 Reed Cage Question

[Kirt13]

Hi,
I just got a new V-Force3 Reed cage.
When looking through the reed cage at all of the pedals, I can see a good bit a day light through the tip of the pedals.
Is this normal? Are the tips of the pedals not supposed to be flush on the cage?
Thanks for the info.
Kirt

[All250R]

No, they're supposed to be flat. You'll have to modify the cage to get the petals to sit flat. It seems to be common in these cages. I want to say the Delta2 wasn't as bad, but even any light in my opinion is poor...

[derby]

Originally posted by All250R
No, they're supposed to be flat. You'll have to modify the cage to get the petals to sit flat. It seems to be common in these cages. I want to say the Delta2 wasn't as bad, but even any light in my opinion is poor...

That is not necessarily true. The pressure will do the complete closing.

Poor for what?

[wilkin250r]

Have you contacted VForce about it?

I know that in 2-stroke boat motors, it's extremely common to have a "reed opening" specification. The reed doesn't have to sit flush, as long as the opening is less than the specification, for the reason that derby posted above. The pressure in the crankcase will close the reed all the way.

I've never found any specs like that for motorcycles, but it's possible that VForce can answer that question. I'd talk to them about it, because if it IS brand-new, you either want the answer to that question, or arrange a refund or exchange.

[All250R]

Originally posted by derby
That is not necessarily true. The pressure will do the complete closing.

Poor for what?
The maintenance specification for reed petals usually call for checking for gap under the petals, like Wilkin says. For example pg 3-13 of the trx manual says: "Check the reeds for damage or fatigue and replace if necessary. Replace the valve with a new one if the rubber seats are cracked or damaged, or if there is clearance between the reed and seat." In this case though they're calling for replacement with any measure of a gap.

So, if v-force thinks the petals do not need to sit flat, they should indeed offer an explanation that they currently are not printing on the box because typically it indicates wearing petals. However, in this case the cage itself is not flat enough to keep the petals flat; the petals are new. So it's not even a tolerance or measurement of wear... In fact, it's a best case scenario.

Take a straight edge against the petal surface and you'll see light shining under different parts of the edge. The reason this is "poor" is because it appears to be a quality tolerance acceptance "gap" during the manufacturing process. For my money the petals should sit flat on a new cage and not regularly violate right out of the box how you typically measure for worn reeds (other than them being outright missing pieces).

I've observed that a reed cage that has petals that are showing light are harder to start. When the single act of replacing the petals is performed the problem goes away or is diminished. In that case, even if you don't see a significant running performance loss for having reeds that don't naturally sit flat, difficult starting is not something you should have to deal with after paying for a new cage.

A new CR cage will not suffer from this problem. ESR's machined surfaces don't either, but these plastic molded cages do and it's not unique to his cage or even that version. Petals do gap when they're getting tired. So if the petals do not have to sit flat, then how much gap tells you they're fatigued... I think it's a normal standard to expect the petals to sit flat on a brand new cage.

[All250R]

Just to show what these cages often look like when they're new here are three pics of new vforce cages. I assume he has a high expectation for quality. I did as a consumer and now owning an engine performance business I will choose over design rather than under perform. 2c:
New Delta2 CR:
http://all250r.com/Scraps/Delta2Gaps.jpg

New Delta3 CR:
http://all250r.com/Scraps/Delta3CRGaps.jpg

New Delta3 TRX:
http://all250r.com/Scraps/Delta3TRXGaps.jpg

Different Delta3CR after I think 3 desert trips (short season):
http://all250r.com/Scraps/Delta3CR2Gaps.jpg

[derby]

ESR reeds are the worst. You could use the gap logic on a metal reed, like what comes in the 250r and other oem reed setups. But none of that is true for carbon fiber reeds. The flex you get with carbon fiber will never allow them to lay flat. There is enough pressure to flatten these down on the block. Since they are carbon the bend and flex really easy. OEM honda metal reeds will not flex or bend like the carbon reeds. As I said the internal pressure will close the reeds down. When your motor is running your reeds will never be slightly cracked open like you see they will be open or closed.

I also have brand new v-force cages and they all have the same opening as you seen in the above pictures.

The v-force 2 reeds have less tension (due to thickness) and are said to open up more. The v-force 3 reeds are supposed to have more tension and be slightly thicker with the trade off of not opening up as much. However I prefer the v-force 3 due to the reed stuffer design and there are no metal parts to come loose in your motor.

[All250R]

Originally posted by derby
ESR reeds are the worst. You could use the gap logic on a metal reed, like what comes in the 250r and other oem reed setups. But none of that is true for carbon fiber reeds. The flex you get with carbon fiber will never allow them to lay flat. There is enough pressure to flatten these down on the block. Since they are carbon the bend and flex really easy.

Maybe I'm not getting what you're adding here. But Esr reeds sit flat. I mentioned before that if you put a straight edge on the cages without the petals installed and you can see what the cause of the gaps are. The ESR block is machined flat and there are no gaps (w/ carbon fiber reeds)... Now whether that cage works well for you or not... I think the opening is hard to match a small boot to... but that's another story.

Also, what metal reeds are you talking about? The reeds installed from Honda in the CR and TRX are not metal - they're flexible fiberglass. But like I said before if the gaps with new petals are ok with you, have at it. I believe it causes issues, especially when the gaps aren't even at the tips, but at the sides of the petal. That's not for me and so I don't tell anyone it's ok.

Just as an academic point, the Delta2 has thinner petals by .1mm, but the leverage point it lifts against is at 27mm as opposed to the Delta 3's 39mm. So there isn't supposed to be a big tension difference between the two.

[Buttermilk]

Some of the 250R motors came with metal reeds, stock, from Honda. I've seen first hand, myself.