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GT186 30mm Dell' Orto carb question

Posted: Mon Dec 07, 2020 3:34 pm
by Nic
Hi all. I have a quick Q re. a 30mm Delly carb set-up for this kit, which I've always previously used a 25mm carb on.

A while ago I was given a 30mm carb and l/hand 30mm manifold for the 186GT kit as a (requested) birthday prezzie. When I tried to fit it today I hit a snag. Basically, the upturned bit on the manifold raises the carb so that the top strikes the underside of the petrol tank. The tank doesn't have a cut-out but I'm not convinced that even if it had it would make a difference. I'm using an MBD carb rubber bit I can't imagine that would make a difference

Anyone else have that problem? Thanks in advance...

Re: GT186 30mm Dell' Orto carb question

Posted: Mon Dec 07, 2020 4:07 pm
by Nic

Re: GT186 30mm Dell' Orto carb question

Posted: Mon Dec 07, 2020 4:43 pm
by Toddy
Nic you will need a tank with a cut out I'm afraid as the manifold sits different on the LH side ive just built one luckily i had a TS cut out in the long range tank i have fitted

Re: GT186 30mm Dell' Orto carb question

Posted: Mon Dec 07, 2020 5:24 pm
by Warkton Tornado No.1
Pity to molest a new carburettor cap, but the fasteners can be replaced by countersunk screws & the cable outer have a tight bend elbow into the cap. You might even get away with a OEM brass choke cable elbow as a throttle cable elbow.

Lots of elbows, cable sheaths & in line adjusters are available from suppliers on line & you might get away with a well placed dent in the tank (use a ball pain hammer held in place & hit it with a soft faced mallet) or reposition the tank upwards with thicker rubbers.

(You could probably get a PWK to fit & for a lot less money to set up but I understand that many feel it is 'safe' to go with the common choice of the PH range. They are tried & trusted but will never be a two stroke tuning specific product like other Dell'Orto products due to the round slide)

Re: GT186 30mm Dell' Orto carb question

Posted: Mon Dec 07, 2020 5:27 pm
by Warkton Tornado No.1
Pity to molest a new carburettor cap, but the fasteners can be replaced by countersunk screws & the cable outer have a tight bend elbow into the cap. You might even get away with a OEM brass choke cable elbow as a throttle cable elbow.

Lots of elbows, cable sheaths & in line adjusters are available from suppliers on line & you might get away with a well placed dent in the tank (use a ball pain hammer held in place & hit it with a soft faced mallet) or reposition the tank upwards with thicker rubbers.

(You could probably get a PWK to fit & for a lot less money to set up but I understand that many feel it is 'safe' to go with the common choice of the PH range. They are tried & trusted but will never be a two stroke tuning specific product like other Dell'Orto products due to the round slide)

Re: GT186 30mm Dell' Orto carb question

Posted: Mon Dec 07, 2020 5:42 pm
by Burnside
I run a PHBH30 with my GT186 and that is fine with an Oiltek tank with a cutout

Re: GT186 30mm Dell' Orto carb question

Posted: Mon Dec 07, 2020 7:17 pm
by Rich_T
You are using a long range tank without a cut out. With original tank and airbox the carb fits fine. If you have a cut out on the other side of the tank you can use a RH side 30mm manifold assuming you don't have a battery tray

Re: GT186 30mm Dell' Orto carb question

Posted: Wed Dec 09, 2020 11:38 am
by GeorgeS
A snake head carb top may help you out here.

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Re: GT186 30mm Dell' Orto carb question

Posted: Fri Dec 11, 2020 1:02 pm
by Nic
Hello all. Thank you for all advice, which is food for thought. The picture I showed is actually of a tank with a cut-out. It may be a rubbish tank for all I know, although it's been in there for a little while and the 25mm Delly sits nicely. It definitely feels like the 30mm manifold sits differently. I'll take some more pics later tonight and tap your knowledge a bit more... In the meantime, thanks again - and I mean it: these Lambretta scooters are weird sometimes, aren't they? :lol:

Re: GT186 30mm Dell' Orto carb question

Posted: Sun Dec 13, 2020 10:24 am
by Cav
Nic wrote: Fri Dec 11, 2020 1:02 pm these Lambretta scooters are weird sometimes, aren't they? :lol:
They sure can be, but the original design was always tight on tolerances and shifting the carb from one side to the other is always a bit of a stretch. I'm a bit old school as I've said many times and I've always struggled with the reed manifold set up needing to shift the carb. The TS1 longevity and proven popularity speaks for itself, but original configuration tuning sometimes has it's advantages. Now if we want to talk weird, lets get into the electrical systems :roll: