Vhsh

[a-teamlambretta]

Im struggling to set up a 30mm vhsh.

225cc none reedvavle motor with a Gori exhaust, Anyone using one... Need to know some base settings.

Cheers simon

[Warkton Tornado No.1]

I can't help specifically with the VHSH but would suggest you persevere as it is a 'proper' two stroke carb with guillotine slide.

However, I find that slide cutaways tend to be 40 -45 across the range, so that would be my starting point.

A pilot of 50 would be my base line as would an atomiser DQ262. I am not one to be tempted by having a larger than necessary atomiser as you lose out on the fine tuning. You should always check that an atomiser is large enough in any case by running with no main jet. How many do that?

Needles are something you need to research in the charts. They're not cheap, so what have you got now?

I hope that helps

[a-teamlambretta]

I have the right ball park jets and atomiser... But when i get the motor running there seems to be more fuel being spat out than whats going in...thought i had the piston in the wrong way but its not and timing is spot on... Cant work it out...

[Warkton Tornado No.1]

If the inlet timing is not excessive (do you know it?) then pilot, mixture screw & needle profile are the main influences.

Are you going to state every detail of what you have fitted in the carb, as otherwise no constructive advice can be given?

Even some 'standard' kits have too much inlet & need stroking or longer pistons to make them civilised. As much as I like Rapidos, 60 mm stroke minimum to make them more useable...

[a-teamlambretta]

Will post later when i get home and cheers for the help

[nsaints]

Here's my Jetting for a a 30mm VHSH, not exactly what you have but maybe a starting place you can refer to

TS1225 (bog standard out the box porting)/Latest variant Ron Moss clubman

30 VHSH with breath LTH elbow, breath sweet filter running under panels
MB shorty manifold
MJ: 155
Pilot: CD1/45
Float Valve: 300
Atomiser: DP262
Needle: K21/T2.5
Choke: 60
Slide: 50

24.5 degrees
Kytronic Setting: 1

[SimonC]

VHSH settings

valve 350 atomiser dq269 needle K92, main 150, pilot 42 over a CD1 atomiser, slide 50. Only just started to do a few miles to work and back, its fairly close, but will need a dyno.

Quattini 225 RM ST Box pipe, tea strainer filter, little or no spit back

[a-teamlambretta]

Will have a look this morning... and report back

[Warkton Tornado No.1]

Will have a look this morning... and report back

Bear in mind that the settings thus far received are from reed valve engines.

So the things that will be different are:

Atomiser type (DQ for piston port engines)

Pilot size (piston port engines get more 'loaded' with fuel @ low revs)

Slides as much as 50 IMO are always too lean on piston port engines. In fact even the old VHB's that always seem to only have 50's fitted (or available new!) had to be 'converted' to 45's & then ran extremely well. Better than the PH tosh IMO.

Main jet likely in 120 - 130's range.

[a-teamlambretta]

Right then....

50 slide
Main 145
Choke 60
Idle 48
Inner Idle b 48
300 float valve
Atomiser dp266
X13 needle

I have a few spare main jets and atomisers

[Warkton Tornado No.1]

Right then....

50 slide
Main 145
Choke 60
Idle 48
Inner Idle b 48
300 float valve
Atomiser dp266
X13 needle

I have a few spare main jets and atomisers

I'm not surprised the engine is anything like close with the jetting.

Bear in mind that the settings thus far received are from reed valve engines.

So the things that will be different are:

Atomiser type (DQ for piston port engines)

Pilot size (piston port engines get more 'loaded' with fuel @ low revs)

Slides as much as 50 IMO are always too lean on piston port engines. In fact even the old VHB's that always seem to only have 50's fitted (or available new!) had to be 'converted' to 45's & then ran extremely well. Better than the PH tosh IMO.

Main jet likely in 120 - 130's range.

I've run VHB/C's from 34 mm up to 39 mm & had to set up PH's for other people & piston ported engines tend to run a similar slide cutaway & atomiser types across the range. These are fundamental facts.

I think you will be chasing your tail if you try to jet in with anything else.

[a-teamlambretta]

I have a good selection of jets in that ball park and dp266 and dq268, So will pop the 266 in and a 130 main. Will have to order a smaller Inner Idle and choke.

What needle would i need?... I have a few on stock

Cheers for the input

Simon.

[a-teamlambretta]

Cant find a cd 1 Inner Idle on dellorto uk site?

[ULC Soulagent]

Cant find a cd 1 Inner Idle on dellorto uk site?

https://www.dellorto.co.uk/shop/dellort ... sion-tube/

[a-teamlambretta]

Cant find a cd 1 Inner Idle on dellorto uk site?

https://www.dellorto.co.uk/shop/dellort ... sion-tube/

Will that fit the vhsh... As its not listed for that carb?

[Warkton Tornado No.1]

Phew!

The CD1 exists for a reason, but is no way critical, or instrumental in the base settings particularly for a piston ported engine. That's my opinion through experience, but, if I'm wrong, please, somebody correct me

The DQ atomiser range is important.

The slide cutaway (less than 50) is important.

The Dell'Orto carburettors with guillotine slides, such as you have, are excellent for two strokes. The downside is the cost of slides, needles & even atomisers. I must have six or seven complete VHSB/C's, the spares to tune them & therefore must be over a grand's worth sitting there, mostly 'not in action for the majority of the time.

That's why, on a road engine, the PWK's (licenced from Keihin, made now by Koso, OKO, Polini etc) are a revelation in terms of cost & set up.

[ULC Soulagent]

Well if other members have fitted it then what ya think
I’ll be ordering a few soon but not from robbing Bastards euro carb
The secondary idle I think controls the air through the progression stage( might be wrong but that how I interpreted it)
The Cd1 has larger holes and further up the tube than the B- range which are tiny by comparison.

[a-teamlambretta]

I have just totted up £100 for a new 40slide, atomiser, choke and Idle.

Kosso yoko ono pwk copies are £30 with a few jets chucked in...made from hi grade chineseium... I will get 3... Old chinese manufacturing proverb one in a million might fit and work


For sale genuine dellorto vhsh 30 comes with a selection of jets, needles ect
£399 delivered to your manor via recorded delivery

[a-teamlambretta]

https://www.amazon.co.uk/dp/B07J377CT3/ ... UTF8&psc=1

Thinking of this one or

[Warkton Tornado No.1]

IMO & experience, that size of venturi will work & TBH a 34 mm PWK that I have was initially tried on 'only' a mildly ported 200.

My considered opinion is that it functioned better than it should have, suited air filters fuss free & never had any cold or hot start issues.

The 200 ended up with a 30 mm venturi PWK Chinese copy which I blueprinted & that size proved to be as good.

The 34 currently resides on a TS 70 x 60 that had to be extensively ported as it had thrown a rod. Again, superb carburation. Eventually, the 34 will be destined for a ported Rapido 71 x 61 & the DIY adjustable power jet will come into action.

I have videos of the 200 & TS running but have yet to try posting them on this Forum.

If you can get a 32 for less money, I think that would be ideal. The PWK's are so efficient, they punch far above their weight but are very controllable. They are OEM on some trials bikes which is very significant....