Older installer's needed for advice please

[lukie]

in the next week or so I plan on converting my new toy, I have a 850cc reliant robin trike, I have a nice little 15litre gas tank need to sort out a switch kit, power valve and a vaporiser, the trike is 40bhp so any vaporiser will do the job, so I have 2 question's

Firstly i need to know what I should do with the mechanical fuel pump do I t into it so it keeps flowing but not supply the carb?

secondly would it be better to retro fit a lambda sensor and run a leo kit (or similar)
there's not much room for a lambda hence thinking I need a power valve instead

the water feeds are small on the engine that have been bypassed when the body was removed, I'll have to find some pipe adaptors to make them bigger to feed the vaporiser

[lukie]

just been looking on tinley's site, they have this

Lovato Mini D20 Reducer/Vaporiser

waterless gas in and gas out, I can modify the multivalve in the tank to give me gas out, would this fit and give me enough gas? would be easier then piping up the water system I could hide it under the fake bike petrol tank

[rossko]

Are you sure your tank valve has a liquid takeoff? Many of these little "scooter tanks" are supplied as vapour takeoff from the outset.

I'd have a think about modifying a liquid multivalve to vapour pickup - you have a teeny supply hole. I don't think you'd get 40bhp vapour through a 3mm valve. Apart from insurers worrying about 'unauthorised mods' if poop met fan.

Shutting off petrol should be like any carb, just put a stop solenoid between pump and carb.

[lukie]

The tank is an odd ball thing, it's a miniature 15l stako tank 30 degree with stargas multivalve I think it is, it looks like new wouldn't fit it to anything normally but the trike does about 60mpg anyway so 15l tank should get me around 120 miles before refill

If I put a stop solonoid in would that not damage the mechanical pump seals ?

[demonicwillow]

How about installing/teeing in a fuel return line back to the petrol tank and using the shutoff solenoid to open the return when on gas and close it for petrol ?? that way you wouldnt risk knackering the mech pump.

[Gilbertd]

Mechanical pumps squirt using a spring. The diaphragm is pushed against the spring and the spring then pushes the fuel out. If no fuel is being used the diaphragm stays at the end of the stroke with the spring compressed. That's how you get a constant fuel pressure, by the strength of the spring, not by the lever that operates the diaphragm against the spring.

Although it it was me, I'd just fit a blanking plate over the hole in the block where the pump would fit and use an electric pump hidden away somewhere.

[classicswede]

That little vapouriser is useless. On a 10hp engine they were only lasting a couple of months of use, upgraded the fleet to the bigger lavoto one and they are much better.

You would be better off using a electronic rather than a vacuum operated one.
Petrol shut off solenoid should be fitted after the fuel pump

[Tinleytech]

We can assure you that the mini Lovato reducer is certainly not 'useless', we have supplied many of them and when fitted/used correctly, thay last many years (just like any good quality reducer).
Perhaps not suitable for your project though.

[classicswede]

They might work ok on a generator with constant throttle but when you have variable demand they do not last. They are very sensitive to any contaminants in the fuel, the seals wear through quickly causing gas to leak through (over pressure) and the levers wear groves into the pivot pins.

On a generator or any other constant throttle engine yo would not see the problems as rapidly as the parts do not have to move as much.

[lukie]

We can assure you that the mini Lovato reducer is certainly not 'useless', we have supplied many of them and when fitted/used correctly, thay last many years (just like any good quality reducer).
Perhaps not suitable for your project though.

the little reg was not used, tinley offered a reg suitable but wasn't in stock for a few weeks, I have now got a AC reg from LPG shop mounted on it's side under the fake petrol tank, it's done around 300 miles so far almost trouble free

it's a single point open loop system, did around 160 miles for a tank of LPG which cost's a massive £12 ish to fill ! got a 15L tank from friend, the mechanical fuel pump is going to be removed this week blanked off and an electrical fuel pump fitted with a prime switch and a safety cut off relay, the trike won't start on LPG so when I switch off currently I have to turn the engine over for 30 sec's plus to fill the carb bowl before it starts