Some years ago I built an Ulster Replica with Ruby head, oversized inlet valves, flattened cam followers and a 1 1/4" SU carb from a Mini mounted on an Alan Raeburn manifold.

It has a scuttle tank and runs very well but has never started reliably (especially from cold) unless I dribble some neat petrol down the carb.

I had always thought this was because there wasn't enough head of petrol above the carb so last week I eventually fitted an electric SU fuel pump but it made no difference.

I also have a lightened flywheel with no ring gear so have to start it on the handle.

I'm beginning to suspect hand cranking simply doesn't draw enough air through the carb to suck in enough fuel. Any comments or suggestions would be much appreciated.

John.

Location: Paignton, Devon

On the Chummy with gravity fed side draught SU I often resort to engine start spray - colloquially known as 'Start Ya B*st*rd'

Cheers, Tony.

Location: Melbourne, Victoria, Australia.

Oh, beware the perils of Easy Start or Quick Start! A seductive mistress which leads to a serious addiction as the car gets the taste for it and will not start without its daily fix!

Location: Ripon

Easystart, or similar, is a one way route best avoided in my opinion.

I have a similar set-up on an Ulster style special. I have used an MGB type SU pressure pump (not a sucker) mounted just above the n/s chassis in the engine compartment. Starting has not been a problem in 15 years, but if it has been standing a month or two the engine has to turn quite a few times before it fires. The starter motor spins quite well on a 12v motorcycle battery, but starting was not a problem in the early days when I had no starter. I concur about easystart; it's best avoided. Do check for air leaks in the induction system. I once sorted a Seven where poor running was caused by the manifold not fitting the block properly.

On the 1930 fabric saloon I ran in the 60s (Bought from Robert Leigh all those years ago)I had an early 1-1/8" SU. This had a 'tickling plunger' on the top of the float chamber which pushed the float down so the petrol level rose to enrich the mixture.
I wish I still had that carburetor but it disappeared somewhere along the line. I don't know what it was originally fitted to, rumours were Lanchester 10.
Might be possible to make up something similar to do the same job.

What is the main objection to using a spray?

I only recently adopted it after a few years of sometimes erratic cold starts in the winter.

Cheers, Tony.

Location: Melbourne, Victoria, Australia.

We always have to "tickle" the SU on tge Ulsteroid for a cold start. After that its fine until preperly cold again.

Conventional motor trade "wisdom" is that easy start etc, damages the valve seats progressively making the starting issues worse.

Stuart.

Location: Teignmouth

My 1931 saloon which has a side draught 1 1/8" SU operating on gravity feed from the scuttle tank, starts instantly on full choke after which the choke can be pushed in. It is on 12 volts which spins the engine round nicely and I do use super grade unleaded.
One of the many benefits of the SU carb is easy starting, there are no fiddly jets to become blocked.
If neat petrol or easy start spray is needed to fire the engine, there must be a problem either with petrol getting to the carburettor jet or alternatively, an ignition problem. If you have an in-line fuel filter I would remove it, I have never found them necessary with the SU.
I would also fit a starter, hand cranking is no fun when the engine stalls in busy traffic!

Actually it's stalling in traffic which is my biggest concern but getting the necessary parts to add a starter motor is proving difficult (or expensive). I think I'll just go over everything again including the carb and timing then, if all else fails, get a can of easy-start.

Location: Paignton, Devon

Is your Mini SU one of those with a little flexible pipe feeding the base of the jet? If so it could be the problem. I would check to see whether it is perished or restricted. I have never used one, the SU's on my cars are pre-war!

If everything is correct your car will start instantly, in good condition and properly set up A7's are generally very easy starting cars irrespective of the carb. If the problem is carburation I would suggest low fuel level, wrong needle meaning the jet is set too high to compensate and starting mixture will then be weak, or the enriching device (choke) is not working.
low compressions, worn valve seats, ignition faults will all cause problems

Location: NZ

Location: TINOPAI NZ

Burlen Ltd stock new float lids with brass tickler pin for 2" , 2.3/8" and 3" diameter float chambers together with all other new spares you may require for your SU carb.

http://sucarb.co.uk/float-chambers-spares/float-lid-assemblies.html

Jeff.

Location: Almost but not quite, the far North East of England