Scooterotica

these are often used by racers of course ,but are rarely seen on road lambrettas for some reason.
many tuned vespas now benefit from the use of fuel pumps,so would they not give the same advantages to tuned lambos....
which are ,better and more consistant fuel flow..less probs due to lack of flow/starvation ...
do any of you use a fuel pump on your lammy ..?
if so which do you prefer..vacuum/diaphram or electric .

This was suggested to me by someone for my RB250, but I haven't heard much about it.

If its decided to use a vacuum fuel pump where and how is the best place to tap into the crankcase pressure?
I was thinking of a tapped hole near the bump stop as the casting is thicker and the bump stop would help protect the pipe but im unsure if there is enough space, or a tapped hole on the reed housing on a ts1 barrel
suggestions and thoughts????

i would go for a hole into the crankcase from the highest point poss ....somewhere in front of the bump stop and between the engine mounts...

sean brady scooters wrote:i would go for a hole into the crankcase from the highest point poss ....somewhere in front of the bump stop and between the engine mounts...

This is where I had mine on my TS1.

I,ve had one on my GP for over 10 years. RS Suzuki 225, 37mm Dellorto, think it has a 2.5mm valve seat. Think the pump is Mikuni. We put it on a long time ago!

I have a variation on my Abarth Lammie.

I use a fuel tap from a Suzuki Bandit (though I suspect the same tap is fitted to many models in their range) which is connected to the crankcase like a diaphram pump. However, it doesn't pump, it just doesn't flow fuel when the engine isn't running. The avoids me having to have a fuel tap which, with the one-piece fibreglass back-end, it not possible.

There is a "prime" setting to bypass the diaphram, which also acts as a reserve. I understand that these types of diapham-controlled taps are common on twist and gos.

My diaphram feed is located between the engine mounts, above the bumpstop.

I always go the easiest route and that is into the reed block housing on TS1's and Vespa reed conversions,the vacuum is there otherwise the reeds wouldn't open.If you are careful you don't even have to take the cylinder off.If the pressure is too strong a 1mm to 1.5mm float valve can be used in Dellortos or a loop system of fuel pipe with a restrictor fitted .

they often use fuel pumps on vespas, because the carb sits higher then the fuel tank - so there isn´t enough pressure to feed the carb on high tuned engines and to empty the tank completely.

on our lammies the tank sits higher than the carb, so i don´t think we really have to use fuel pumps....

Stampede wrote: on our lammies the tank sits higher than the carb, so i don´t think we really have to use fuel pumps....

Gravity doesn't always feed a carb fast enough.