I recently took delivery of a pair of MotoTassinari V-Force 3 ( V301A ) reed blocks. (AG602C stuffers) from The Two Stroke Shop.
They are actually designed for the '87 - '00 & '02 CR125, but are a really good fit on the NSR. Just needs a bit of tweaking with the Dremel.
They look like they will flow way better. Especially where I flowed the LH Top crankcase volume.
And they don't block the rear transfer port on the LH Top cylinder as much as the standard reed block either.
Supposed to give a much crisper throttle response with about an extra 2 HP (per cylinder!!) across a broad rev range. Bloody sales talk.
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| No reed petal backstop on new reeds |
The first step is to cut off the existing stuffers on the Reed Block back plate. I just sliced them off with a knife. The kit supplies a couple of washers and nuts. You are supposed to use them to space the reed blocks from the backing/stuffer plate, giving a slot to run the hacksaw through.
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| The washer/spacer provided creates gap for hacksaw |
Now I used a Dremel to match up the original intake shape with the new V-Force stuffers. The V-Force stuffers are made to suit a CR125, so it just needs a bit of a tweak to get everything flush.
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| Bottom lip |
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| Upper lip |
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| New stuffer ground smooth and flush |
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| Other side also ground smooth and flush |
Also, as you can see in the pix below, the rear transfer port of the upper left cylinder is no longer blocked by the standard reed block.
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| Rear transfer port partially blocked by standard reed block |
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| Almost no blockage of port with new reeds |
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| No reed petal backstops to hinder flow out to side transfers |
I do not know how much these new reed blocks are going to cost me, but probably around NZ$500 !! for the pair. Not cheap.
Now a few days later. I have been using a small file to smooth off some small edges on the red cages. At the factory the reed petals must be cut with an abrasive water jet cutter ot similar: one side of the petals is a bit rough on the edges, so I used a bit of 600 grit paper to smooth it off. Hopefully this will make them seal a bit better. Spent about 2 hours filing and sanding just to get them perfect.
Also, in order to get the central reed petals out, you have to prise the 2 central "sticks" out sideways. This is not very obvious and is not mentioned in any of the paperwork.
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ReplyDeleteNice mod, thanks for sharing.
ReplyDeleteI'm wondering what's your opinion about the new angles that the mixture enters the crankcase. From the photos, it seems like there will be interference between the crankshaft webs and the incoming fuel mixture.
Also, have you checked the relation between the OEM fiber and V-Force carbon reeds? I remember V-force reeds to be about 0.4mm which I think is great for mid power but might restrict flow on top rpms.
Keep up the good work.
Nick
Wouldnt the new V301C fit better with a hole measurement of 1.28"x1.56" vs the V301A of 1.20"x1.37"
ReplyDeleteThanks for the update. Sure, I guess now, 5 years later, we can expect to find a better fitment. Looks like the 301C is suited to the Honda RS125.
ReplyDeleteThe 301A that I used were to match the CR125. So anyone reading this, go for the 301C.
On the longevity side, how are the V-force reeds holding up? Some ppl are complaining that the reeds chip quickly and cause issues during starting...
ReplyDeleteWell I have done only about 200 kms plus 4 track days.
ReplyDeleteI pulled the carbon reeds out and they were in perfect condition.
I have seen others that fray badly after only about an hours use.
I think it REALLY HELPS A LOT if you do what I did and carefully file off all the jagged edges on the carbon reeds with a fine file or similar. The way the carbon reeds get cut seems to leave a nasty edge on one side of the carbon sheet. This can only hasten the time to fray.