Scooterotica

it may be the one that jigs from the mac cruisers used to own, mbd conversion built for a lad in north london called jezz "guy" rackley may be able to shed more light on its origins.

all i know is that it spent most of its time in my garage in bits but when it did go it was savage

almost 20 years ago now but im sure it was sold to a bloke in lincoln

cezeta wrote:it may be the one that jigs from the mac cruisers used to own, mbd conversion built for a lad in north london called jezz "guy" rackley may be able to shed more light on its origins.

all i know is that it spent most of its time in my garage in bits but when it did go it was savage

almost 20 years ago now but im sure it was sold to a bloke in lincoln

Nick, this conversion has been on for a while actually. Several BSSO racers use it.

Supereibar wrote:

cezeta wrote:it may be the one that jigs from the mac cruisers used to own, mbd conversion built for a lad in north london called jezz "guy" rackley may be able to shed more light on its origins.

all i know is that it spent most of its time in my garage in bits but when it did go it was savage

almost 20 years ago now but im sure it was sold to a bloke in lincoln

Nick, this conversion has been on for a while actually. Several BSSO racers use it.

so im assuming then this convertion didnt use the kdx /kx barrel ?

you guys talking about the barrel as well huh? I should have supposed since the stud spacing seemed wrong for a Lammy... And obviously, that isn't allowed in BSSO racing.

cezeta wrote:it may be the one that jigs from the mac cruisers used to own, mbd conversion built for a lad in north london called jezz "guy" rackley may be able to shed more light on its origins.

all i know is that it spent most of its time in my garage in bits but when it did go it was savage

almost 20 years ago now but im sure it was sold to a bloke in lincoln

I belive thats correct ! Igot it off Trevor Maxfield or Max the basge man to most for peanuts.
Air cooled KX 250 ! Very low transfer and very high exhaust timings. Iv got a new cylinder for it now and was going to weld the top of the exhaust and then skim the top of the cylinder down to make them more four speed box friendly ! I wanted a 64 mm crank for it but MB refused to sell me one unless he did all the work ! Im not a rich man by any means so its gone on the shelf and stayd there !

grimspeed wrote: I wanted a 64 mm crank for it but MB refused to sell me one

very odd ...

He sent me this e-mail

I remember the engine, but have not seen it since it left the shop.



The only problem it had was the mag gasket leaked, so you may want to look at that.




As I've said Im only rebuilding top ends using my 64mm cranks so people don't make a mess of it and instantly blame the most expensive part and me.




There will be no difference between 64 and 64.9mm strokes!




I've done a lot of research over Christmas to do another similar conversion, the KDX 200 air cooled looked good with a power valve! But this led to problems over running the power valve, which we can control with our new ignition system and a servo!




Any way, our crank should do the conversion and doubt if you will have a problem, but our cranks run a 22mm pin, ideally it should be 24-25mm but this leads to even more problems.




From memory the transfer timings are very low but the exhaust port is quiet big, so you could weld the exhaust port up and lower the timings.




I have on stock a 76mm piston already.




We can bore it out and replate or resleeve it, depending on what year cylinder it is.




Does this help any more?




Cheers Mark







On 2 Jan 2010, at 09:25, graham jones wrote:





> From: [email protected]
> To: [email protected]
> Subject: Re: Contact from www.lambrettaspares.com
> Date: Thu, 31 Dec 2009 18:06:34 +0000
>
> Hi
>
> Questions on forums make me laugh!
>
> Why is a 65mm crank so important?
>
> We do an off the shelf 64mm stroke Race-Tour crank which can be
> assembled to suit the rod you ask, which from memory of doing race
> tuning KTM cart engines is the same rod!
>
> BUT because these are not simple off the shelf cranks, I will only fit
> them into engine casings and assemble the top end, this way I only get
> slagged off if I do it wrong!
>
> Cranks are usually around £525 but this rod cost more so maybe £600
> not what the forums say £1200!
>
> Cheers Mark
>
>
>
> On 31 Dec 2009, at 17:39, graham jones wrote:
>
> > MRB0688K
>
well i got my hands on one of your old air cooled kx 250 cylinder conversions quite a few
years ago.its a bit tired now so i thought i would spend some of my hard ernd upgrading.
i got another cylinder .untouched and thought it would be good to try and run it with the original stroke for the cylinder which as im sure you know was 64.9mm.i am well aware this would bee unproven in the lammy casing and could well end in tears.such is life.i know i would probably be better off investing in a dac but that would be a waste of a realy nice bit of engineering from yourself. plan is to use a 76mm kawasaki jet ski piston. js 300. and add some ali to the top off the cylinder to bring the port timings in line with the use of the four speed box. now dose that make any scence as to why a 65mm crank is important.now are you interested in helping me.and can we do business


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any pics of the barrel and head

This is my old motor.MBD originally built it for a guy up the road from me at the time in north London.Long 64mm crank,air cooled ported KX250 barrel.As Cezeta posted it did spend the bulk of its time in pieces due to the mag side air leak and its self destructive nature(it was not made for touring)...but when t was running I can honestly say I have not ridden a road going scooter as brutal;not so much a throttle as an on/off switch.Once it chimed in you were along for the ride.Was sorry to see it go,but at the time I'd had enough of scooters so just let it go for peanuts-£400 I think-in '94...also let my Italian Electronic go the same week for £500.DOH!DOH!DOH! KLK78K where are you now?

Thats interesting ! I was told its a 60mm crank. Ill have to do some measurments and see what it came with !
If it is a 64mm .Ill get a new con rod kit and get it sorted !