[vhgmcbuddy]

Hi David,

Have thought several times of fitting a modern carb to an industrial engine. Bought a cheap Chinese copy for a Honda for around £12 and was amazed of the quality and how they could sell it for that amount. Am not a fan of some older type carburettors, they are quite crude in comparison to more modern versions. The float/needle arrangement and the method (if any) of emulsifying the fuel is often poor. Could you send some pictures of the manifold and throttle linkage arrangement and I will try to think of what replacement carb may be suitable.

Off now to get a nearly new Locin 1” pump for £40. The Villiers/Alcon will be sat in the shed for a while yet I think.

Best wishes,

Grahame

[vhgmcbuddy]

Hi David thanks for your help so those engines do have an automatic decompressor on them so hopefully that explains the low compression reading I will have a look at it again over the weekend and try the glove ideas suggested by Grahame.
Thanks again for your help.
Best wishes William

[vhgmcbuddy]

Dear David,

Fantastic descriptions and pictures of your precision engineering skills. You remind me of an old boy who does a few little jobs for me. He has made scale stationary, steam and aircraft engines from scratch. What he can do amazes me and he is in his eighties.

Without those abilities people like me have to try to work with what we can obtain. I had the problem of getting hold of some piston rings for a Gravely D. No chance as named spares, but whilst researching fell upon Hastings Piston Rings. After reading their very helpful technical guidance, found a set that fitted in their brochure. Although they were an American company, they had a franchised distributor in the UK. So ordered them. They could have also supplied some for a Jap 5, but in the end as Cox & Turner had them in stock. Purchased some from them.

Was told once Ford Consul pistons would fit a Jap 5. This was not true, but after the success with the rings I tried to do the same with specialist piston suppliers. Was hoping to find a way of getting a replacement piston when it was not obtainable as a named spare part any more. But have drawn a blank. I cannot find on the internet a catalogue where I can cross reference: bore, gudgeon pin diameter, compression height and crown profile. Does anyone know of a method of doing this. Where it may help David, or anyone else, is to obtain nominally obsolete pistons to keep their old engines running in good order.

My elderly engineering friend has a large and rare oil engine with the plug, or more like a pair of electrodes, sitting in a chamber outside the cylinder. It’s a lot cruder than the Rover one shown in your pictures. As for the carb, I would just fit a modern one if parts are no longer available. As I think some of the older types were just too rudimentary and unless in good condition, cause a lot of problems. But I am more interested in performance than originality. Others may take a different view and can well understand that.

Best wishes,

Grahame

[vhgmcbuddy]

Hi Grahame thanks for your reply,yes it is a Briggs & Stratton engine that was the bit I should have mentioned. I will give the gloves idea a go. I will also have a play with the fuel mix adjustment as well. I found the valve clearance and it should be between 2 and 5 thou on the inlet and 5 and 7 on the exhaust. I contacted a Briggs & Stratton agent today and a set of rings if available are almost £60 pus another £45 for the gasket set. The fact that it’s so starts 2nd or 3rd pull from cold and it’s overall condition I would not expect it to need such major surgery like piston rings etc.
I will let you know what I find.
Best wishes William

[vhgmcbuddy]

Hi William,

Am presuming the mower has a Briggs & Stratton engine. If so, I have found they sometimes need fine tuning with the mixture screw to run well. Have a 12HP model on a Ransomes Bobcat mower and even 1/8th of a turn on the screw can make a big difference. Do not think a normal compression tester is the best tool to use on hand start single cylinder petrol engines. They really operate best when the engine is running at least electric starter speed. The correct tester is a leak down type. But if you do not have access to one and I do not. I use the thin latex glove method. Fit the glove tightly over the exhaust and bring the engine onto compression. If it rapidly inflates, its the exhaust valve leaking. Do the same test over the carb inlet and if possible over the oil filler hole. This will test for blowing past the rings. The glove will inflate a bit, but if it rapidly does so, it identifies the problem area. You valve clearances seem a bit small to me. Would check the manufacturer’s recommendations.

Best wishes,

Grahame

[vhgmcbuddy]

Hi David,

My Villiers engined Alcon pump is definitely 1½”. It does have a model number on it. I got it from a retiring market gardener, who sold me all the delivery and suction hoses too. It ran poorly, so I did my usual top end, points and carb service, it then ran well. It was noisy though under load and drank fuel. The Honda GX160 is a lot quieter and less thirsty, the Robin EY15 even better on both counts. The pumps have a superior performance than the Alcon too. So am on no particular rush to get the Villiers/Alcon combi running again. Very interested to hear that the pressure gauge had a red line at 20 psi and it rarely achieved that. It explains a lot. A friend of mine got 16 spraylines (they are each 15’ long) with a Villiers/Alcon combi and it never worked very well. He said he then got a Honda pump that ran the spraylines fine. He grew lettuce, watering regularly. He filled the fuel tank full and left it to run dry whilst he went off to do another job.

When I first took the Alcon pump apart, found the seal had all but disintegrated. Vulcan Water Seals were very helpful in identifying a replacement and were keen for it to be added to their database. The Clark pump had been purchased by a chap who had had his house flooded and wanted it in case it happened again. He then moved house and had no further use for it. He started the engine every few months, but did not know he was meant to put a bit of water in it to keep the seal lubricated. When I came to swap the pumps over I could see the damage done, so put a new seal in, again from Vulcan. Just for the fun of it I tested the suction with a vacuum gauge. This is when I found the Alcon pump was not achieving the recommended 20-25 ins Hg negative pressure. The others passed.

Had an idea to increase pressure by pumping from one pump, through another to replicate a multistage pump. But it did not work, the second pump was the Alcon and the Villiers engine struggled with the flow rate from the Clark pump. I did get an increase in pressure, but it was not enough. Quickly realized a multistage pump needs to have a calibrated flow from the first stage to the second and maybe a different impeller design too. My effort was doomed to failure.

Best wishes,

Grahame

[vhgmcbuddy]

Hi David,

Have a 1½” Alcon pump powered by the Villiers engine. Got it in the 1980’s and used it for irrigation. But then got sprinker rotor heads that needed a higher pressure (30 – 35 psi) than my original ones. The pump also started to take an age to prime. Fitted a new seal kit I got from Vulcan Water Pump Seals, it improved the suction, but still the pressure was not sufficient. Got another Honda engined Clark pump (26 meter head), but still the pressure was not enough. So did try to link the two together, but I only got a small increase in pressure. In the end got a Robin engine Koshin pump (30+ meter head), it performed well.

Took the Alcon pump apart again and found the engine crankshaft was pitted with rust. I think these indents allow a small amount of air to get past the seal and effect the pump’s performance. I was going to go along a similar line to yourself and sleeve the crankshaft. But without your skills I was going to use a hardened stainless steel shaft repair sleeve. Proposed to fit it over the shaft then grind off the flange. What do you think of that idea.

Decided I would swap the Koshin pump and fit it on the nearly new Honda engine, the Clark pump onto the well used Robin engine. Found that the crankshaft on the Robin engine had grooves on it where the seal was in contact with it. Also the Clark pump seal was not in the best condition, so replaced it with one from Vulcan. Now have two pumps that perform well, although the Koshin is the superior one.

Dropped on some Evenshower Oscillating Spraylines and these operate at a much reduced pressure. In fact I now use the Clark pump and only need half revs from the Robin engine. The original pendulum operated oscillation valve was worn out and leaked everywhere. So make another from a pair of ¼” ballvalves. But the operation was too stiff for the pendulum, freeing them up caused leaks. Have just spent Easter Sunday making a new valve with a 3 port L configuration. Have high hopes of success and will be starting irrigation this week. It needs it too, in my part of the world near Evesham we have not have any significant rain for 6 weeks or more. Am going to put a pressure gauge on the irrigation system to see exactly what pressure the spraylines need. They are very satisfying to see operating, gently and quietly going from one side to the other in true 1950 – 60’s market gardening style.

Best wishes,

Grahame

[vhgmcbuddy]

Hi Will,

Many thanks for that. Cox and Turner is one of the suppliers I have for parts and they are usually my first port of call for engine spares. Can get rings a bit cheaper from a manufacturer, but prefer to use Cox and Turner because they are fellow enthusiasts.

Have fitted new rings and ground in the valves on many engines. But some I have worked on have been left stood for years in damp conditions. The valve contact surfaces and the seats have become very pitted with corrosion. Managed to lap most of them out, but the contact surfaces widened, ridges and grooves formed too. Got good compression to start with, but after some hours work it tailed off. Put a thin rubber glove over the exhaust and the carb inlet, it blew up when the engine was near the end of the compression stroke. Am going to get the valve seats cut and the valves themselves re-faced. But as the contact surfaces are now so wide, am going for a 3 angle cut. When I have it done will post something on the forum to share my experience. If anyone has had this done, would like to know what they thought of the results.

Best wishes,

Grahame

[vhgmcbuddy]

Thank you!! I’ll do that now

Regards
Will

[vhgmcbuddy]

Hi Grahame,

Cox and Turner supplied the rings. £55.20 inc delivery. I’m so pleased with the engine – now the rings and valves have been done I can hardly wind it over the compression is so good. Ready for many more years!

Regards
Will

• This reply was modified 1 year, 6 months ago by vhgmcbuddy.

[vhgmcbuddy]

Hi Will,

Did not see your posts until this morning. I set the tappet clearances on a Jap 5 & 6 to 10 thou on the inlet and 20 thou on the exhaust. These figures are stamped on the inside of the inspection cover. Have also fitted new rings if required and can vouch for the increase in compression when this is done. Have two Douglas SV54 engines that I got when I purchased a couple of Trusty’s that were taken apart so that they could be stored. Intend to reassemble the machines one day and will make sure the engines perform well. If they need new rings, I will fit them. Out of interest, where did you get the rings from.

Best wishes,

Grahame

[vhgmcbuddy]

In the end I used 10 thou inlet and 16 thou exhaust (not sure why 16 exactly!). With a hone and new rings it now has huge compression and runs beautifully

[vhgmcbuddy]

Thanks to Andy – my enquiry to Villiersparts gained the response <no stock>. Never mind, my
search continues, and meanwhile no doubt I can construct something to do the job. Not too difficult to change over if I find the right thing.

Dave

[vhgmcbuddy]

Ps the last magazine I have is dated dec ‘24

[vhgmcbuddy]

Hi
Dates for lawn mower manufacture can be acquired freely by coming to The Hall and Duck Trust, go to our web site http://www.hdtrust.org and send an email from there (the site is being changed so take no notice of dating costs)
Regards
Andrew Hall Archivist

[Author]

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