Howard Gem Series V

[sidevalve5]

Hi,

Have been bequeathed a Howard Gem Series V from a dear old friend’s estate. Although he actually said to his brother “give it to Grahame, he likes messing about with that old c**p”. Do not know the history of the rotovator, but he used to be a market gardener, before moving into agricultural contracting and groundworks 25 years ago. He may have used it on his market garden, or purchased it later to use on his veg plot. It looks as though it has not done a huge amount of work and someone must has thought it was worth putting a brand new set of tyres on it. Also the oil in the Kohler K301 engine looked new.

Had a play on Sunday to see if I could get it going. There was no spark. Did what I usually do, removed the points, honed them on an oilstone, refitted and set them up. Result was a good, fat spark. Took off the carb, it was full of thick gum from the old petrol. Gave it a clean and a blow though, also put some wind through the petrol pipes. The seal on the petrol tap was breaking up, so even after a clean up and blowing through, the fuel just dribbled out. Still got some to pump through, although there was a lot of air in it. Gave it a swing and she fired up. At higher revs it gave out a good crisp bark and did not smoke at all once it had burnt off the oil/paraffin mix I had put down the plug hole before attempting to start it. But it would not run well at low revs, no matter what idle or main jet settings I did. It is a fueling problem and think will be an easy fix.

There are two other faults that I would like the combined experience and expertise of the club members to advise me on though.

The first is that something had clearly dropped onto the throttle linkage, knocking the rod off the carburettor butterfly valve operating plate. It bent the plate and the clip that holds the rod in place has flown away. Straightened the plate easily, but cannot find a company to supply the clip. Does anyone know if they are available. Can see what I think is similar on Amazon, but have to get 4 for £22 and they maybe the wrong ones anyway. There are single ones on sale via ebay in the USA, have messaged the seller to see if he would post to the UK, but as yet, no reply. May have to make up a new linkage with M5 ball joints and studding. Did this on a Trusty when the old linkage wore out and could not get a good tickover. But be good if someone knew where I could get a clip for an easier fix.

The second and what could be the most difficult problem is that the clutch is stuck. Tightened the rod adjusters at the handle and gearbox ends right up before I could get a bit of ‘feel’ that something was moving. Rocked the machine back and forth to free the clutch, but it was a ‘no go’. Have to do this on a Clifford Mk1 and a Colwood I have when they have been stored overwinter. Did read online that the most usual problem is the clutch plates seize on the 6 pins they should slide along. But it could be worn friction plates or something else. Am going to undo the bell housing bolts and split the engine from the rest of the machine to have a look. Can anyone who has experience of these clutches and their operation advise please.

Many thanks,

Grahame

[andyfrost]

The clutch is more than likely the plates sticking , but hard to tell exactly until you have split it.You sound quite mechanically minded , so I’m sure you’ll identify what wrong.
The linkage issue , I would be inclined to make my own.
Fuel issue , if you nkow someone handy who has an ultrasonic cleaner , 15min cycle in one should cure the problem.

Andy.

[sidevalve5]

Many thanks Andy for replying to the post.

Will work my way through the fuel system until I find what is the matter. Got to get the petrol tap flowing freely first. Also will soak the carb in cellulose thinners, acetone or white vinegar. Think I will experiment with all three on different parts to see which one performs the best. If there are still bubbles in the fuel from the pump, will have a look at that too. The chap who left me the machine had an ultrasonic cleaner, but I think it was sold along with his vast array of plant and machinery.

Agree about the throttle linkage, will make my own. Can get a pair of M5 ball joints for £5.20p off ebay which will give a stable mechanism. Have found original linkage rods going through holes that can enlarge over time. With a big single at tickover it can cause the throttle butterfly valve to flutter, so the revs are not as steady as they could be.

Agree again the most likely cause of the lack of clutch operation is sticking plates. My only doubt about this is when I picked the machine up there was zero resistance on the clutch lever on the handlebars. It was only by tightening both adjusters to their maximum, could I feel something was moving. Managed to download the service manual and it does go through the clutch itself, but limited info about the mechanism that operates it. The photos are not very clear. It looks to me the clutch lever at the gearbox end has a pawl on it that engages with the clutch trust sleeve that in turn presses against the clutch trust plate on the clutch unit. It is this area that I have concerns about as if something is broken there, it could be terminal for the machine. The other thought I had was the rotovator was used with the adjusters up too tight, inducing clutch slip, eventually completely wearing out the friction plates. Which may account for all of the adjustment used up on both ends of the operating rod before any ‘feel’ is felt by the clutch lever. Or the nut that secures the clutch unit onto the clutch shaft may have worked loose, so the whole assembly is pushed towards the engine. As previously, any advice is most welcome before I split the machine.

Grahame

[andyfrost]

Rather than ponder over what at present are merely guesses ,just split it and then evaluate.Personally , I wouldn’t use thinners/acetone/vinegar , at any cost , ultrasonic cleaners are truly a great asset , and should cure the problem.
A photo of your exact engine would really help.

Andy

[sidevalve5]

Dear Andy,

A big thank you again for your sound advice.

Am 95% certain the rotovator was a good machine before it was put away 25+ years ago. The only nagging doubt I have is over the clutch, why is there some ‘feel’ on the handlebar lever only when both adjuster are tightened to their full extent. Do not want to spent time and money on it, only to find there is something broken that cannot be fixed with the clutch. If it is just worn friction plates, or the bearing knackered on the engine adaptor plate, then obviously can do those. But as you say, can only assess this once I have split the machine. Was really after advice from someone who had a lot of knowledge of Howard Gem clutches and what to look out for before I undo the bellhousing. Decided the re-commissioning process was to get the engine running first and if that was good, move onto the clutch. Like to do some research before I tackle a job I am unsure of. Find that the experience of others is invaluable in that respect. It can save time and possible damage if you try to disassemble a part that has a retainer you are not aware of.

Have always used petrol and an airline for small parts cleaning. Found Gunk and a pressure washer great for removing thick oily sludge on engines. Mostly petrol and a good brushing has removed gum on carburettor’s, except the really hard to shift historic coatings. Have googled ultrasonic cleaners for carbs and some say they are brilliant, others say so-so because the small passages are not fully cleaned. But am going to take your advice and see if I can find someone with one and chuck the carb in.

Have got a Zenith 24T2 carb with an adjustable jet on the Jap 5 on my Trusty. Replaced the original Jap carb with the Zenith and it was that that I made up the new linkage for. The Zenith was removed from a Trusty that was left outside for decades. Put a service kit on it from Villiersparts, that included a new throttle spindle. The old one had a big flat on the linkage side, so air could be sucked into the carb. The new spindle then made a huge difference at tickover and throttle pickup, which is so important on a Trusty. But sometimes it will start by the third swing of the starting handle, others not even after twenty on full choke. It appears it is not getting enough fuel to start it from the main jet to the orifice in the ventri, with the chamber not being clean and smooth, preventing the petrol from being sucked through it with a single swing of the handle. Luckily a Trusty can be started with a strap, so I can get it to go. But re-built it last year, so it has full compression, getting a bit long in the tooth to keep having to turn in over with the strap. When I find someone with an ultrasonic cleaner, will take both the Walbro and Zenith carbs for a clean.

Have attached the pictures. One way or another I know I can get the fuel system sorted out quite easily. Have a feeling it may be the petrol tap only delivering a fast drip, in turn making the original diaphragm on the fuel pump let air bypass it, delivering frothy petrol to the carb. That could be the real cause of the problem. But having the carb ultrasonicaly cleaned will not hurt either. Will be very interested to see the results to both carbs. Have you ever taken a clutch apart and if so, what did you find.

Grahame

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[john-e-w]

Hi Graham
From the latest photos, I would say that the wheels are on the wrong sides as the “V’s” on the treads should be facing forwards not backwards.

Regards
John E-W

[andyfrost]

You can get away with bypassing the pump altogether , and rely on gravity feed. Removing the engine for the split couldn’t be easier , remove throttle cable , fuel pipe , and ignition kill switch wire(if it has handlebar mount) , undo bell housing bolts and it comes apart , it really is a simple operation, you should then see what could be the problem.

Andy.

[sidevalve5]

Hi John,

The tread direction was what was on the machine when I collect it. The tyres have been fitted, but have never touched soil. They were deflated and the righthand one ‘set’ over towards the gearbox. When pumped up there was a bump on the inner wall, so it rubbed against the gearbox. It was a devil to move the machine. When I got it back I deflated the tyre, pulled the area of the distortion back, held it there and put some wind in. It wetn pop, so I need a new inner tube.

Have always understood that rotovator tyre tread direction is reversed to that of a tractor to prevent the machine being pushed forwards quicker than it should be by the action of the rotors. Be interested to hear what the general opinion is.

Grahame

[sidevalve5]

Dear Andy,

If the pump is causing the problem will get a new pattern diapham from China a £5.80p. Always fit a fuel filter to my working machines as a small bit of rust can come off the inside of the tank, rubber particles from pipes, even with E5 petrol and dirt from the petrol can when filling up. A local hire company always fit a fuel filter to their new plant.

Looked at an Irish lad on YouTube undo the bell housing. Jack on the rear, a trolly jack under the engine, disconnect the fuel pipe, throttle cable, kill switch wire, undo ten bolts and it easily pulls apart. As you say, a piece of cake. But he found the adaptor plate bearing had broken up, it rattled around and damaged the six pins. Have heard all sorts of tales of broken shafts, gearboxes and bearings on Gems.

Have limited use for the rotovator and indeed have a low opinion of them. They are good for chopping in the crop ready for ploughing, or preparing a seedbed when the soil conditions are just right. If used when its wet, they compress the soil structure, especially in our Evesham clay and any clods produced dry out to big hard lumps that you cannot get down. But the Gem looks like a good machine and with little work, can find a use for it. Got a Clifford Mk IV I want to restore if only because I like the colour and shape of the bonnet.

Grahame

[john-e-w]

Graham
Have a look at picture 3 on our Home page

John E-W

[charlie]

Re tread direction, I have always thought the same as Graeme, V forward for traction, V backward to reduce tendency of rotavator to push machine forwards.

[sidevalve5]

Hi all,

Work on the Gem will be curtailed for a while. Was on an 18 month NHS waiting list for an op for a blocked vein on my leg. With 4 months to go had a call to say there was a slot available yesterday from a cancellation. Took it and am now laid up for a while. When I get active again will be flat out on my veg plot, soft fruit and orchard in my spare time, am still working. So no time to play with machines, unless urgent repairs. One of the problems with using such old kit is the constant maintenance to keep it going. But that is part of the fun, get great satisfaction from getting them to operate at an optimum level and then working with them.

Have never used a large walk behind rotovator with rubber tyres, so do not know if the direction of the cleats on the tyres makes much difference. Someone told me that they should be opposite to a tractor years ago, so that is what I understood. Have a Clifford Mk1that came with the tyre cleats pointing backwards. It was owned by an old boy who became so infirm he gave up his veg growing and swapped it for a load of logs. This new owner used it for years until it stopped working with no spark. Muggins bought it for £40, the vendor was very honest and said the coil had packed up. He thought it could be repaired with an external Honda 90 coil. So had a go, stripped the secondary windings from the original coil and hooked up the primary windings (which I understand rarely fail due to their thickness) to the external coil. But it did not work. Put in a Villiersparts coil and then had a good spark. Not the cheapest repair, but do use the roteo (Evesham slang for rotovator), it does a good job for its size and sounds a lot different 4 stoke singles. It will not chop in tall plants and is unstable over rough ground due to the wheels being so close together. If it hits a big stone, the flywheel will turn on the crankshalf, it then has to be re-timed. But its a gas to use.

My other roteo is an early Clifford Model A with steel wheels. Bought it in the early 1980’s from a chap who was packing up his part-time market garden. He wanted £70 for it and had a Trusty for sale too. Did not really want the Trusty, but it had a rebuilt engine, plough and cultivator frame, so agreed to take it off his hands for £25. Have used that same Trusty for 40 years. Its well and truly knackered now, apart from the engine and clutch. Have another two Trusty’s I bought in bits, both with Douglas engines, one with a reserving gearbox and transmission brake. The plan is to get one going in tip top working condition and put the Jap 5 engine from the retired Trusty on the Clifford. That has hooked tines on the rotor and I think does a better job than the L blades. Got some new tines years ago from Chester Hudson, he seemed to have massive stocks of all sorts of parts. I wonder what ever happened it all, does anyone know? The Clifford used to loose its gearbox oil from leaking seals where the rotor shaft came out of the central casing. Understand the original seals were leather, would like to replace them. Does anyone have any ideas about that too?

Will post an update about the Gem when its either working, or if there is a serious problem.

Grahame

[andyfrost]

Wishing you a speedy and healthy recovery.

Andy.

[sidevalve5]

Thanks Andy,

Did not know what to expect when I arrived at the hospital as had no contact with the consultant since the day of diagnosis 14 months ago. They have developed less invasive techniques, so a wire with an ultrasonic probe burnt the inside walls of the deep vein. A chemical foam was injected into the shallow vein. All went well and will hopefully continue on the road of a rapid recovery. Was previously painful to walk after 20 minutes or so, more difficult too over rough ground. Could only use the Trusty in short bursts.

Was offered a cheap Clifford MkIV after a chap made a bonfire too close to it. He lit it and left it to burn. The next day he found that the bonfire must have flared up overnight, the Clifford’s tyres caught, the machine was wrecked. My Clifford is in good condition, but has no compression and the exhaust has broken off. This exhaust formed part of the barrel on the Jap 6. So thought the burnt Clifford would be good for spares, it has an intact exhaust and compression. Think the Lucas SR4 mag is OK, but the HT pickup is burnt, so have not tested it yet. The Zenith 24T2 carb body is black, but seems OK otherwise too. Have found a chap with an ultrasonic cleaner. His main business is automotive lighting, but he also restores British bikes. We had a good chat on the phone, he knew all about gummed up carbs. He also plays guitar and says broken strings make excellent jet cleaners, another tip was to put WD40 through an orifice and check the pattern of what come out the other end. Am going to take the Gem carb, the Trusty and black Clifford Zenith’s. Whilst I cannot use the Trusty until fit enough, be good to get the carb cleaned in the meantime. The butterfly valve is a poor fit in the ventri, so do get air bypassing it, the tickover is a bit too quick. Will have a look at what I can do about that too.

Grahame

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