Atomic Reed Valve on Rapido

[Chris in Margate]

Too much spitback on my current set up so I want to reed valve a 225 Rapido I bought last year.
Just drilled 2 holes in a holed piston without problems so no worries there.
What is the difference in performance between the Atomic Mini and Atomic full size assembly ?
How big a carb will they accept ? I normally use my Koso 30mm which has an external spigot of 38mm and I have another new 30mm Koso power jet with a 34mm external measurement across the spigot.
Any advice gratefully accepted as I come into the 21st Century.

[ForemanBob]

Cannot comment on the Atomics... I have an LTH reed on my Rapido, and max it will accept is a 30mm carb... which is plenty for the engine.

To get the most out of your setup best to cut a boost port to the inlet.

[Chris in Margate]

Does it clear the frame ok ?

[a.lo.v2]

i have recently fitted a small atomic to a 225 race rapido which i have been having horrendous spitbak from. fresh hone and new rings did not cure it. cured now but cannot get it jetted right , engine acts rich but plug says weak dyno needed have upjetted alot from previous settings PWK 26. having said that i did not mod piston( Wossner)and not found better economy yet? chose the small as wanted a smoother /more economical ride rather than all out performance.
will need some mods top corner hit frame, small chamfer to nearest fin and rear rubber fixing touched engine mount lug (would not be a problem if packer fitted) oh and head cowling i bought an AF ts1 modded cowl but still needed cutting, maybe the RB one is more suited. so work in progress really but good luck.

[a.lo.v2]

oh and it came with a35mm rubber that is correct for the oko PWK

[YAMLAM]

i also run an Lth reed on my Rapido 225,It came with a 30mm carb rubber,i purchased a Atomic rubber to suit a 25mm Phbl Delly, this has lasted just over a year, it has split all the way round, just replaced
it with an MD rubber, much better fit to the carb than the Atomic, hope it lasts a bit longer !
Think there is an article on here( Scooterotica ) by darryl taylor regarding carb to reed valve sizes, from memory a 28mm is about as big as you need to go on this size reed block.
Oh and yes the vlth clears the frame ok, cant comment on the Atomic.

[Minority]

Fitted the MB shorty to my Rapido last year, got to say it went together very nicely. It was relatively easy to cut a boost port and the compact MB shorty left plenty of room for a filter with my 30mm OKO PWK clone. You can get a choice of rubbers with the manifold to suit a range of carbs. Cowling has to be trimmed and a few cylinder fins as well. There is also a new 6 petal reed option that is meant to give a bit better performance.