Rapido 250 cylinder reed valved with triple boost port....

[drunkmunkey6969]

Customer brought a Rapido 250 cylinder into Sean to see if it can be made good and tuned up.......and an MB reedblock conversion done ,ever eager to help out, Sean talked it through with the chap and they settled on a triple boost port option, a few new holes in the piston, a reed-valve conversion (obviously), and a little tickle to the exhaust port (widened and raised 2mm ).....here's what Sean had started doing when i turned up, its had more work since but i had to go, so these are the pics i got (below). It'll then need a light hone, new rings and a bit of tidying up......but should be a good tune when finished.

[tarmac tickler]

i have done a similar tune to a 185 ally kit (ebay 80 quid) remote reed valve (home made) taking it to york dragway this weekend to see what it does,, come along i,ll race you!!

[tobytyke]

I know its rude to ask these things...but what was the cost approx for this upgrade...im looking to tidy up a rapido classic kit that as just landed...and it looks like something that would suit me to the ground...hope i havnt offended you. :fb:

[lamy150]

cant wait to see this baby on the dyno

[Muppet]

has it broken through the cast liner to the alloy where you cut the slots; would that effect it,

muppet

[sean brady scooters]

no it hasnt actually and even if it had it would not affect it

[sean brady scooters]

porting costs and modifications in this particular case amount to approx £150..but the engine was already out of the frame ...that accounts for all the barrel ports ,piston mods and exhaust port mods also matching ex to stub and inlet to reed block ..(removing all the fins etc to make the MB block fit etc ).
basic engine rebuild was over and above this as was aslo porting crankcases in this instance .

[Muppet]

what pipe and carburettor are recommended for the kit; would it work with 2/22 and af clubman,

muppet

[corrado]

What was the objective to achieve .... torquey frugal tourer or street racer?
What's the plan for carb, exhaust and gearing?
Any pluses or minuses for the MB reed valve over the LTH version?

[sean brady scooters]

What was the objective to achieve .... torquey frugal tourer or street racer?
What's the plan for carb, exhaust and gearing?
Any pluses or minuses for the MB reed valve over the LTH version?

lol the objective is to make it go like stink ,and extract as much power and performance from this as poss taking everything into consideration .
af 250 rapido,s are notoriously thirsty and not that powerfull .many folk complain about the vast fuel consumption whilst not getting the power or performance to be expected from smaller cc motors or even a 200 stage 4.
and thats why its a very common practice now to reed valve these kits.
also and because of the lack of TS1,s available and the fact that these are now fetching £500 its more and more attractive to convert your old rapido to reed valve possibly ...
who knows ..all i do is what my customers ask for .
this particular motor is gonna use an ADS 5 pipe with an Amal 34 /or delly ..with gearing to suit .
and we will let you know how it gets on ..by providing dyno graphs and info etc .