LCGB Forums

I ran a dq267, k6 and 158 MJ for years.
Bit rich low down but was happy as i could ride through it and fine at mid and top.
Could have probably dropped to 266.

Was talking to someone at ambleside who has just spent 160£ + to rebuild a vhsb: side, liner, atomiser and needle
.
Last time i rebuilt i didnt change the liner. It made a difference but i reckon it needed a liner.

Moved to phbh, very easy to set and cheaper on parts

This is no reflection upon anybody's set-up or opinion...

I think too many of us have become reliant on other people's jetting or the results of a dyno test.

A 'seat of the pants' method to assess whether the atomiser in any carb is adequate is to run it with no main jet in it. This is preferable under load - though first gear can suffice - but what will soon be established is that there is no point in using an atomiser far greater than the engine needs. In fact, a larger atomizer is detrimental to the efficiency of the engine as there will be a loss of the best control by the rider.

Bearing in mind that as soon as the set-up of the Lambretta engine is established, the thing will endeavour to emulate a pneumatic road drill, thus wearing out such critical components, I think it best to be as close as possible.....for a while

Warkton Tornado No.1 wrote:This is no reflection upon anybody's set-up or opinion...

I think too many of us have become reliant on other people's jetting or the results of a dyno test.

A 'seat of the pants' method to assess whether the atomiser in any carb is adequate is to run it with no main jet in it. This is preferable under load - though first gear can suffice - but what will soon be established is that there is no point in using an atomiser far greater than the engine needs. In fact, a larger atomizer is detrimental to the efficiency of the engine as there will be a loss of the best control by the rider.

Bearing in mind that as soon as the set-up of the Lambretta engine is established, the thing will endeavour to emulate a pneumatic road drill, thus wearing out such critical components, I think it best to be as close as possible.....for a while

In going smaller on a atomiser then richer on a needle to be safe …. But coming down on atomiser does this have more of a dramatic effect on jetting even if I use a richer needle.

Question : does a richer needle have such an effect as a atomiser change .

lou wrote:
In going smaller on a atomiser then richer on a needle to be safe …. But coming down on atomiser does this have more of a dramatic effect on jetting even if I use a richer needle.

Question : is does a richer needle have such an effect as a atomiser change .

An atomiser of sufficient size is already 'safe' & that is then effectively restricted via the size of the main jet.

The smaller the atomiser, the closer the working faces of the needle will be to the bore of the atomiser.

By establishing the correct size of atomiser, the differences that the various needles will deliver should be markedly different to when they are operating in an atomiser far too large for the engine's state of tune,