Vintage Horticultural and Garden Machinery Club

‘You pays your money and takes your choice’ with mag testing. A ‘Proper’ test rig would be one that can rotate a magneto, be able to measure the voltage and current output of both the primary and secondary coils. Ideally be able to view the sine waves on an oscilloscope and check the spark gap in air with a 3 probe adjustable tester. For fly…[Read more]

Hi David,

Great that with some more work you managed to get the carb to work well. From what I could see of the pictures you posted it looked like there were potential faults in the design. The float may have not moved freely up the central column, it could twist and then stick. How it pivoted against the needle meant it would not hit the…[Read more]

If you have not done it already, firstly I would remove the points, hone any pitting out from the contact surfaces, refit and set the gap to 0.015”, also clean all terminal connections. With the plug cap removed, hold the end of the HT lead 6mm from a clean part of the engine and see if there is a spark. If there is, you have fixed it, if not, c…[Read more]

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…[Read more]

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…[Read more]

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…[Read more]

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…[Read more]

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 suct…[Read more]

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…[Read more]

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…[Read more]

Hi Dave,

Many thanks for the post. Just to clear up one point about ignition systems on small engines and tractors. They all work along the same principle with a current flowing through the primary windings of the coil generating a magnetic field. Which in turn saturate the secondary windings with lines of magnetic force. When the current…[Read more]

Andy, fully concur, if all the components in a magneto coil, points, condenser set up are good. Then so is the spark. Angus Shapland concluded that a Meco transistorized unit was not superior to a good points system. He liked them because it got rid of the condenser and after he had serviced a machine with points for a customer. It was then…[Read more]

Thanks Andy, I did not know that. Have never worked on the close cousins of the Mk 25c. Have become a bit anal about magneto ignition. For years I subscribed to a school of thought that if engine had compression, fuel and a spark from a plug resting on ground. It should go. If the spark was blue and fat, as opposed to weak and yellow, all the…[Read more]

Wish to correct and clarify what I posted yesterday about changing a magneto flywheel. I said it was just the cam lobe and magnet position that was important. Upon reflection, this was misleading, there are other factors too. Including: coil position on the armature plate, magnet to coil air gap and points cam feet position. Everything has to…[Read more]

Hi Dave,

Personally I would do the easy and/or cheap options first. If the multimeter tests are within the range indicated and the points are clean and correctly adjusted. But there is still no, or just a very weak spark. Suspect the condenser and as you say, you can fit one externally. Only fit new, not second hand or NOS. Would enquire at…[Read more]

Heat is one of the best spanners in the toolkit of anyone messing about with old stuff. Got the method of removing a Briggs & Stratton flywheel from multiple American YouTube videos. They put a wedge opposite the cylinder and a pry bar next to the barrel. Put the point of small air chisel on the end of the crank, pull the trigger and give the…[Read more]

Thats a good idea, had not thought of that. A method I use to remove Briggs & Stratton flywheels is to put some wedges between the flywheel and the armature plate. Get a compressed air chisel, fit a point to it, place it in the centre of the crankshaft and pull the trigger. Never feel comfortable doing it though, armature plates are thin…[Read more]

Hi Dave,

Had another idea that may solve your problem. If the HT and LT continuity tests are fine, you could fit an external Meco transistor ignition unit. If you can get to the wire terminal on the hot side of the points, you could disconnect them and connect with a wire fed from the Meco unit though the back of the armature plate. The Meco…[Read more]

Hi Dave,

When undoing the flywheel nut, there is a few turns when the nut feels free, where it transitions between tightening onto the crankshaft and starting to pull the flywheel off the taper. It then goes tight again and if you continue to turn or hit the spanner, it almost has the feel of a thread stripping. But it is just the action of the…[Read more]

Another way of getting bearings that I have done many times is to get one from one of the large online suppliers. I have used Bearing Boys and Simply Bearings. If the bearing has a manufacturer and a reference number on it. You can cross reference it with the company’s lists. If not, measure the OD, ID and width and put that in the company…[Read more]