Evo air cooled/ carbs

S

smc/polini

Well-Known Member
Hey, those of you who have the evolution cylinder, what carb sizes have you guys tried or what carb sizes are you running. Just curious because I'm running a 25mm dell'orto. This thing is a gas guzzler and is too loud for street use :)

I just want to see the different things people have tried.
 
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you should get a doppler airfilter, that will help with the noise. if you ever get your bike raced tuned then you might want to go with the 28 del. of course that carb is goin to drink. you should see how much the strokers drink with oko 30 and 34mm carbs.
 
no need modify, check out the dekker.nl site. it will fit perfect. george might be able to get you one if you wan to wait for about a month or 2, or you can order it from dekker and get it in about a week.
 
I'm just borrowing this topic.

I've got a AC TPH with the Polini 47,4 kit, but it modified to match the EVO gen. 7 exhaust.

What carb should I use? I've decided for a 21mm D'O, but would the 25mm or 28mm D'O be a better choice? It's not for street, but only race and sprint.

- Neser
 
Originally posted by Neser
I'm just borrowing this topic.

I've got a AC TPH with the Polini 47,4 kit, but it modified to match the EVO gen. 7 exhaust.

What carb should I use? I've decided for a 21mm D'O, but would the 25mm or 28mm D'O be a better choice? It's not for street, but only race and sprint.

- Neser
Click to expand...

go for a flatslide if you will run a race setup.. here in my country most of the fullrace 70cc scoots uses a 28mm flatslide carb. ;)
 
Neser- I'd go with a 28mm if you are going for full race. I tried tuning the 21 Dellorto with the evo cylinder and it just would never run good. I even had to get a different needle and many hours of tuning just to make it drivable. A couple guys here in hawaii have run OKO 30mm with their evo's.
The 25mm d'o works ok on my bike.
 
Originally posted by Rydah1
no need modify, check out the dekker.nl site. it will fit perfect. george might be able to get you one if you wan to wait for about a month or 2, or you can order it from dekker and get it in about a week.
Click to expand...

rydah, I tried looking for that site, I googles it and typed in dekker.nl and I can't find it. Do you know what the actual web address is?
 
Originally posted by emo
go for a flatslide if you will run a race setup.. here in my country most of the fullrace 70cc scoots uses a 28mm flatslide carb. ;)
Click to expand...
Like the Mikuni TM24. Have one on my RS, witch I just sold, nice carb actually.

But isn't the 28mm a bit too big, if you still want a fast flow trough your carb?

Just measured my Polini reedcage, and the square hole is aprox. 790,9mm2, a 28mm carb must then be 615.8mm2. So a 30mm (706,9mm2) would probably fit better for max flow and performance, or am I totaly wrong?

With the venturi-inlay (those two small plastic tings that you put into the reedcage) it's only 283,5mm2, witch is the same as a 19mm carb.

So, as far as I can calculate, I should go for the 28mm D'O or flatside or just a 19mm D'O, if I want something to match the reedcage.

Hope you can either werify or reject this teory of mine.

- Neser
 
or you can just pick the carb you would like to use (i suggest the 24 flatside) and then adjust your reed to the right size(max 30% larger then carb)
 
on our 28mm carb. we uses taiwan made big manifold to match the size.. a fullrace 50cc they use 21mm-24mm carb. 70cc, 26mm-28mm & 90cc, 30mm-32mm.. these are the range of carb sizes that they commonly use on a sprint scoots.. may you could try it..
 
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Hmm, maybe I'll buy another Mikuni TM24, I already have a 180, 200, 210 and 220 jet, another needle-pipe and a 12,5 and 17,5 idle jet.

Just think that it's easier to get jets, needles etc. for the D'O carb.

So now it's down to two carbs, the TM24 and the 28 D'O.

- Neser
 
Neser-
The 28mm won't be too big. And also buy an extra manifold and try this. Run a polini reed cage without the velocity stacks, and take your spare manifold and dremel it out at the base to closer match the bigger reed cage opening. and then run a bigger carb, 25mm+ I would not recommend anything smaller than 25. I realize that people are concerned if the vernturi will have enough velocity going past, but you have to remember this cylinder is like a huge giant port with a few strands of metal around it. It's all port! It will breathe trust me. THe guy here that has a 30mm carb on his evo on a identical bike beats me with my 25mm.
 
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Originally posted by Rydah1
no need modify, check out the dekker.nl site. it will fit perfect. george might be able to get you one if you wan to wait for about a month or 2, or you can order it from dekker and get it in about a week.
Click to expand...

Thanks for the site, I checked it out, but there is no way that would fit on my bike unfortunetly. :(
 
SMC that filter will fit on my bike. i will modify something just to make it fit. thats what these bikes are all about, making things work.
 
Originally posted by Rydah1
SMC that filter will fit on my bike. i will modify something just to make it fit. thats what these bikes are all about, making things work.
Click to expand...

I know, I've had to shave stuff down and cut and custom fit allot of other things, but I litterally have no room for any filter. The frame rail is almost directly infront of my carb. I need to get a manifold that points out at a different angle instead of to the left.
 
Originally posted by smc/polini
Neser-
The 28mm won't be too big. And also buy an extra manifold and try this. Run a polini reed cage without the velocity stacks, and take your spare manifold and dremel it out at the base to closer match the bigger reed cage opening. and then run a bigger carb, 25mm+ I would not recommend anything smaller than 25. I realize that people are concerned if the vernturi will have enough velocity going past, but you have to remember this cylinder is like a huge giant port with a few strands of metal around it. It's all port! It will breathe trust me. THe guy here that has a 30mm carb on his evo on a identical bike beats me with my 25mm.
Click to expand...

Just talked to Moto-Line, Polini dealer in northern germany. Thay told my that my Polini reedcage was designed for the 25mm D'O they're selling, so just bought the 25mm D'O (also got it a bit cheaper :) )

Now I'll just sit and wait for my Malossi flange so I can fit the cooling fan to my innerroter.

- Neser
 
Originally posted by Neser
Just talked to Moto-Line, Polini dealer in northern germany. Thay told my that my Polini reedcage was designed for the 25mm D'O they're selling, so just bought the 25mm D'O (also got it a bit cheaper :) )

Now I'll just sit and wait for my Malossi flange so I can fit the cooling fan to my innerroter.

- Neser
Click to expand...

Sweet! I think you will very happy with how it works out. Will you be jetting it yourself? Let me know how it turns out.
 

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