Page 1 of 3

Little Forty F341

Posted: Tue Sep 10, 2013 8:00 pm
by Jan
Yesterday I came home from a short UK trip.

We visit Portsmouth, the Beaulieu autojumble in New Forest, the Duxford Air Show and I picked up an Anzani Minor that Keith.P collected for me.
Thanks Oyster 49 and Keith.P. for the effort to get me a British Anzani Minor in my collection.

I visit the Beaulieu autojumble hoping to find some parts for my pre-war motorcycle and on the end of the day I was very surprised to spot a Little Forty between I pile of rusty vintage car parts.
The Little Forty was very corroded and it didn’t had a Villiers carb. Then I realised I found a model F with the tiny Amal carb and fancy choke assy.

I never thought I could add a model F to my Little Forty FV and FVP outboards.

As Jeremy mentioned in the other model F topics it has a lot of different parts comparing to the later model F, FV and FVP.
Serial Number F341

Small BS Starter Pulley

Small Transom Bracket with alu 'Cotton Reel' Thrust Block

Small Cylinder and Head with 1/4" Studs

Late 1940's Magneto Base Plate


Re: Little Forty F341

Posted: Tue Sep 10, 2013 8:05 pm
by Stelios_Rjk
Great and really rare little engine on great hands!

Re: Little Forty F341

Posted: Tue Sep 10, 2013 8:07 pm
by Jan
Tiny Amal carb with choke assy
Engine Mounting Lug with P/N and tilt hook mounted with large split pin instead of Clevis Pin.

I think the original throttle lever is replaced by this later Villiers style lever.


Re: Little Forty F341

Posted: Tue Sep 10, 2013 8:25 pm
by Keith.P
That was a very lucky find Jan, not a motor you come across every day, best of luck with the restoration.
P.S. thanks again for the spares.

Re: Little Forty F341

Posted: Tue Sep 10, 2013 8:55 pm
by Oyster 49
It's great when these old motors turn up! 8) Is that 4 that we know about now?

Re: Little Forty F341

Posted: Tue Sep 10, 2013 9:19 pm
by Gannet
Yes, it is four including the Ibsley one. Jan's F341 has the 1/4" studs, and so it probably has the small block etc with the different stud centre distances. I am waiting for that confirmation from Jan.
There will be more out there.
Well done Jan for finding it!


Re: Little Forty F341

Posted: Fri Sep 13, 2013 7:57 pm
by Jan
It took me a few hours to dismantle the powerhead because every bolt and also the piston was seized.

The cylinder, piston and crankshaft is in good condition but the crankcase cylinder base flange and head is badly corroded.

The F model crankcase, cylinder, head and piston is smaller comparing with the FV an FVP models. The crankshaft and conrod looks the same.
On the left a F model crankcase and on the right a FVP model.

The F model piston is 38mm, has very thin rings and a gudgeon pin with alu cap ends like the SD. The FV and FVP piston is 45mm and has circlips for the pin.

The small F model cylinder is in good condition.

The badly corroded head.

Any advise in repairing/filling the badly corroded areas and surfaces?


Re: Little Forty F341

Posted: Fri Sep 13, 2013 9:42 pm
by Charles uk
Jan can you measure the stroke on your F?

If that is fitted with a FV crank it would have a cubic capacity of 40 cc, with a 40 mm stroke crank 45cc.

This is getting stranger!

Re: Little Forty F341

Posted: Sat Sep 14, 2013 2:38 am
by winter
Super Jan, I will visit you soon to admire this beauty.
Lots of succes restoring her

Re: Little Forty F341

Posted: Sat Sep 14, 2013 9:05 am
by Jan
Charles, The stroke is +/- 36mm so the capacity is 40cc.

Thanks Evert, you are welcome.


Re: Little Forty F341

Posted: Sat Sep 14, 2013 11:23 am
by Collector Inspector


Everything is able to be saved and back to square one.

You need a good engineering shop to get things done aye!

Tell the shop what you want. Do NOT count pennies...............get it done right first time and never look back.

This head was stuffed inside and out..............


Re: Little Forty F341

Posted: Sat Sep 14, 2013 12:03 pm
by Oyster 49
For the corroded head, I would think about having the alluminium surface built up by welding, then the face can be remachined flat, like CI's photos. To machine the gasket face I think you would have to locate off the flat surface the head nuts screw onto. Then a skim on the mill with a flytool.

Another option could be to repair with epoxy then machine, but I would prefer to weld then remachine :)

I'd suggest doing the same with the crankcases. Well done in getting those long studs out 8)

Re: Little Forty F341

Posted: Sat Sep 14, 2013 1:34 pm
by Charles uk
Heads are not too expensive to have cast, I've had several done, but don't have the pattern for an F.

Is the spark plug thread helicoiled?

I've been paying circa £45 for a century type head to be sand cast in the same type aluminium but that does not cover any machining, car body type filler can be used to increase the major dimensions by 2% to cover the cooling shrinkage & crater & hole filling, it can be removed afterwards with a bit of heat.

The sheet mild steel gaskets can be laser cut almost anywhere that has a laser or water jet.

Any good machine shop can machine one of these in an hour or 2.

The crankcase face is under so little pressure that a new gasket (was this a steel one?) & RTV will do the job perfectly.

40cc not a Seagull for racing!

Re: Little Forty F341

Posted: Sun Sep 15, 2013 3:33 am
by 1650bullet
Its hard to say by the pics, But what if you just shaved the cyl head down enough till its a flat machined surface. Would the piston come up and hit the combustion chamber :?: . If not it would probably have a high compression and would probably need premium fuel. I know you could not do it to the crank cases because it would alter port timing.

Re: Little Forty F341

Posted: Fri Sep 20, 2013 7:59 pm
by Gannet
Well done for stripping it down so quickly. I expect it will be up and running before long.

I had previously tried to measure the stroke on F201 (which has not been stripped). Using a depth mic I found it difficult to get a consistent result; the average being about 36.3mm. So i have no doubt that your measurement of 36mm is the correct one.
If you are going to have some steel gaskets cut as suggested by Charles L, could you make an extra couple for F201? A couple of FV steel gaskets which I obtained and which had not corroded were clearly coated/plated with something - I suspect it was a galvanized coating. This technically would have been a wise choice and probably galvanized steel sheet would have been readily available.

Good luck in the restoration.