[sidevalve5]

That is indeed sad news. He helped me greatly with queries about Trusty’s and I shall miss his sound advice. His enthusiasm for Trusty’s shone through with everything he said to me. Can I offer my condolences to his family and friends.

[sidevalve5]

Úgy tűnik, elfoglalt dolgod lesz. Remélem, sikerül mindegyiket szépen működésre bírnod. A képen a téli projektem látható, egy JAP 2a, ami egy Alcon vízpumpára van szerelve, és máris jól elkezdtem. Épp most fejeztem be a szelepek becsiszolását, és most már elkezdhetem az egészet összerakni.

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[sidevalve5]

Here are the photos of the sheared Villiers pump crank after a stone came through the suction hose and locked the impeller. Also the 2a grooved key and a cropped image of the bolt threads showing the original paint on them.

The clean cut on the crank vividly demonstrates what can happen when an engine suddenly stops stone (pun intended) dead and the energy created by momentum of the reciprocating parts has nowhere else to go.

Once got a mixer for it’s drum, my old one had started to rust through. The mixer had a Briggs & Stratton engine that would fire, but not run. Was not bothered, as I had a rescued Honda to fit on. But when I had 5 mins free thought I would get the B&S going. But no go, I subsequently revisited it a couple of times, could not understand why a nearly new engine with good compression, a big fat spark and fuel would only pop and bang for a minute or so. Decided to take off the flywheel to check the ignition timing and the alloy key had half sheared. The drum had stopped suddenly, the flywheel still was able to move and it probably saved the engine. It now runs as sweet as a nut, but have it stored away with no use for it. Have been told to always fit a genuine B&S alloy key, never a steel one.

Have a Clifford Mk1with a Villiers 25c. I re-fitted the flywheel using only light taps on the T bar of the socket and glad I did. When using it I hit a stone that stopped the engine and moved the flywheel on it’s taper. Otherwise the 25c crank could have sheared. My Howard Gem has a pin in the shaft from the clutch that is there to shear if the rotors stop suddenly. Some plough and cultivators have shear bolts too to protect the implement. The grooved key and roll pin follow the same principle.

The paint of the threads should put to bed any thoughts that this engine had had it’s cowl off (and by extension the flywheel), since the day it left the Alcon works in 1951/2. A further inspection revealed the felt behind the stator plate, although I fail to see the relevance of it. The roll pin and grooved key are factory modifications most likely done at the JAP works in conjunction with Alcon. It could be a one off, or part of a small batch, who knows. The grooved key is designed to shear and the roll pin that prevents the pulley from being tightened hard against the flywheel, will let it turn if the engine stops dead. Better a sheared key than a sheared crank. On a portable pump used by ill informed operatives, a solid steel key I would describe as a “recipe for disaster” a sheared crank “untold damage”. The roll pin only has to resist against it’s own rotational inertia force whist the engine is running and the action of the starter rope from static. Not much. It’s primary purpose is to prevent the pulley going tight against the flywheel, so it is free to turn if the key shears.

This will be my last post on this subject (JAP 2a flywheel removal) until I have got the engine running. Am not going to descend further into a ding dong battle on this forum about whether the roll pin and grooved key are factory modifications, or a bodge by a mechanic, or the merits or otherwise of a key and pulley arrangement designed to shear. Nor does the fact others may not have seen such a set-up before. In the grand scheme of things, it makes no difference anyway. The important thing is to take care with the re-fitting of the flywheel to ensure the crank does not move over, everything is correctly aligned, there is no resistance or rubbing. It will be during this assembly process when a final decision will be made whether to tighten the pulley against the crank, or re-fit the roll pin. Current thinking is I am attracted to the idea of maintaining a shear capability due to my own experiences and observations. Also would like to put it back to the same specification it came from the factory. Want to use the engine as a test bed for an energy transfer coil conversion. It may have a use for it as an irrigation pump for my Evenshower oscillating spraylines, but it will need to demonstrate comparable fuel efficiency with my existing modern pumps. Being brought up in the market gardening industry it was drummed into me that a strainer should ALWAYS be used on the suction hose of a pump because if it sucked up a stone it would wreck the pump set. I still think the roll pin and grooved key were a factory modification to trial the idea of introducing a shear element into the design. But was quickly dropped, probably due to the cost. If others take a different view, I am totally unconcerned and will move forward with working on the engine as I see fit.

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[sidevalve5]

H7 is a transition fit, where it’s not a sliding fit, but not a press fit either. The flywheel should fit over the shaft and come off again with very little effort. But have some resistance to rotational turning.

There was no felt seal around the edge of the stator plate.

Believe the engine cowl has never come off since it left the Alcon works. So anything that is unusual was done by the JAP factory or possibly Alcon. The steel key has two grooves either side of it, so was designed to shear if the engine stopped suddenly. Modern engines have an alloy key that does the same. Have you or David seen keys like that on a 2a before, because I have not. Could be that the roll pin mod was specified by Alcon, but only for a short while. If the pulley was tight against the flywheel, the key would not shear as designed. Will take photos of the key and the sheared Villiers crank that I have mentioned in a previous post. That was broken by a pump sucking up a stone.

[sidevalve5]

Remélje, hogy teljes visszatérítést kap a kézikönyvért. Ha bármiben tudok segíteni, csak kérdezz. Tagja vagyok néhány Facebook-csoportnak, a tagok gyakran kínálnak kézikönyvek pdf-változatait, hogy segítsenek egymásnak. Postázhatnék valamit, de a motorok ritkák ebben az országban, úgyhogy szerintem nem sok van a kézikönyvvel. Kipróbálhatnál egy másik kezdő témát a VHGMC fórumában, de angolul küldenéd. Nem minden tag tudna számítógépe segítségével magyarra fordítani.

[sidevalve5]

Sok sikert a javításhoz, és remélem sikerül újra rendesen működnie. Nincsenek brosúrám a Tecnamotor motorokról, ezek nagyon ritkák az Egyesült Királyságban. Ne is gondold, hogy láttam egyet. Köszönöm szíves prospektusajánlatát, de csak az általam birtokolt vagy dolgozni fogott motorokról van és kérek információt. Tartson naprakészen minket a motoron végzett munkával kapcsolatban.

[sidevalve5]

Am thinking very much along the same lines. The pulley should be done up tight against the flywheel, the roll pin prevents that. There is a strong possibility that if it is pulled tight it will pull the crank slightly towards the flywheel end. Am going to grind in the valves, so the stator plate has to come off. Will also get the deposits in the flywheel hole and shaft flattened off so I can get near to H7 h6 or js6 in the Limits and Fits tables. Should then be able to put the flywheel on and off relatively easily and see where the problem lies. Can try it with the roll pin and without, tightening the pulley. I think this is a factory bodge and if so, it was done for a reason. It could have also been a method to prevent over-tightening by ham-fisted ‘mechanics’ after the matter was raised. It could have been only done for a small production run, then decided to drop the idea. All I do know is that I do not want to damage an engine that has done little work from new.

[sidevalve5]

If using Windows on a PC, the default program will have a slider in the bottom right hand corner of the monitor with a – on the left, a + on the right. Move the slider to the right to zoom in. Alternatively, with the mouse cursor over the image, roll the mouse wheel up, away from your hand.

The roll pin is actually 3off, 2 larger ones and a centre spacer that is in the middle of the crank. Was going to not use them, but now am having second thoughts. After reading what David wrote, they could prevent the pulley pressing tightly on the flywheel because of a machining error on one of the associated parts. Rather than throw the batch away, fitting a roll pin was a more economic (bodge) solution. The ‘corrosion’ could be a type of loctite to prevent the flywheel moving in and out on the shaft. Am not sure about this. Going to grind the valves as I think this is the cause of the lack of compression, the seats look terrible because of years of storage with the valves open. When I re-assemble, will try to work out why the roll pins were fitted.

Have a 2a on a Colwood that I have had and used for 30+ years. The info I got all that time ago was the points gap is 0.018 – 0.020”, timing 30o BTDC. Have taken a picture of my points set-up and it looks the same as David’s. Believe mine has not had the cowl off since the day it left the factory, so it’s original. Can alter the timing by moving the armature backplate on the slots as shown in the photo. As the cam for the points is separate from the flywheel, can set the timing with the flywheel off. But expect it to be spot on as there is so little wear on the engine. Do not think it has done more than a few 10’s of hours since 1951.

Really pleased to hear Andy was approving of the external energy transfer coil trial. If it works, it should cost £25 max for the first one and £10 for the next 6 as the 125g roll of enamelled copper wire and a roll of heat resistant polyester tape will do several primary coil windings. Can get an external coil for under £6 if it purchased via Temu. It could save some old engines because it is so cheap to do.

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[sidevalve5]

Dear David,

Had another look at the engine yesterday and indeed it does have a head gasket. When I took the head off on Saturday I only took a quick look at it, noting it had numbers stamped on the contact face. It was covered in thick green paint. The numbers were an imprint of those stamped on the cylinder and into the soft head gasket. A closer inspection revealed the head gasket.

I also had a more detailed look at the crankshaft and hole in the flywheel. Both had roughness and have started to flatten it off the shaft. It appears to me corrosion, but not from water. Still think something was on the shaft or in the hole during assembly, maybe an acid type material. The good news is that I can flatten it off so the correct interference is restored. Am going to re-fit and take off until I am satisfied the flywheel will come off as it should.

Your positive reply restored my faith in the VHGMC forum. My understanding of a forum is to discuss ideas in an open, proactive and positive manner, I like to engage in this process. I sometimes feel those who wish to obtain information or expand their knowledge and experiences by posting a subject in the VHGMC forum are often met with apathy and/or negativity. You, the hdtrust and a couple of others are the only exceptions. Facebook groups appear to have younger, more open minded members who are willing to positively engage. This does not bode well for the future of the club.

Best wishes,

Grahame

[sidevalve5]

Am afraid there is a huge variation in prices. It depends very much on the condition and what the vendor thinks it’s worth. That’s often a lot more than it would get in an auction where the starting price is low and the bidders raise it until sold. Suggest one in poor condition is worth twice scrap value, say £25 and 10X that for a good runner.

[sidevalve5]

Andy,

I would agree that a 2A is a very simple engine to work on. Where we will diverge hugely is that because the flywheel was all but welded onto the crankshaft, it was a devil of a job to get it off. Your method would have failed in the first instance. Persisting in it would have damaged or broken associated parts.

Attached are more images of the state of the shaft and the puller method I used, complicated you may say, but a necessity if the seized flywheel was to be pulled off the shaft. It consists of two pullers, one with the 4 hole attachment that I could fit the 3 whitworth bolts into. The bolts ideally needed to be longer, but this is all I could get hold off on a Saturday morning. Because the side hammer element would not fit as the crankshaft was too close to the centre hole. I got another puller to go on the attachment and placed 2 nuts in the middle hole to act as a centring spacer. It involved a 1/8 turn of the puller hex end, followed by several sharp blows on that end, for another 1/8 turn to be done and more blows. Repeating the process many times until it was free. You may describe it as complicated, I believe that I used care, skill, experience and a range of tools, applying them all in unison to do a difficult job.

Again you may say my ignition testing technique that I have shown in the imagery is complicated. I would contend that it is a simple and quick diagnostic method of establishing where a magneto ignition trouble lay. In this case it was a 74 year old condenser with a wax paper dielectric, the primary and secondary coil windings are fine. Sending the ignition parts away to be tested, or just using the substitution method would have resulted in additional time and unnecessary expense in fixing the problem. FYI, testing took 4 minutes, the cost of the polyester film capacitor and board to mount it on is 45p, estimated time, 15 minutes.

You may say too that my intended fitting of an external coil is complex too. To my mind it is not, however I do concede a rudimentary understanding of mutual induction is required. Am not doing it to fix a failed coil, but to do an experiment to see if firstly, it actually works and secondly, if it does, is it better than a known good original system. I want to find out if winding a primary in my own workshop on a homemade jig and fitting an external coil is worth doing as opposed to purchasing an expensive new one. I could then advise others with greater confidence, as I would have completed the conversion myself. I also get great enjoyment and satisfaction from doing such projects.

Grahame

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[sidevalve5]

Jó látni, hogy mivel foglalkoztál, és várom a jövőbeli bejegyzéseket.

[sidevalve5]

Hi Andy,

Please ignore the text in my last post. Am chatting to a chap in Australia who has done a 2A up and asked him about removing the flywheel too. I did the original text to him, them slightly edited it for you. Copied it to paste into the VHGMC forum box and for some reason (think because I had not saved the Word.doc before editing), although the one to you was showing in the box. When I posted it, the one to Baz went!!! No harm done though, just a little confusing. Yours is below:

Got the flywheel off yesterday, had a right game with it. Believe the year of manufacture to be 1951 with the H (missing the bottom left leg) after 2A. Do not think the engine has done much work because there is no wear in the bore and what little carbon there was on the piston and head mostly wiped off with a rag. Took the head off, there was no gasket. Do you know if this is correct.

I do not think the cowl has ever come off because the bolt threads for the tank straps and carrying handle still had the lime green paint I think Alcon put on at their works. Believe Jap supplied the engine covered in red oxide as it is inside the cowl and some of the cylinder fins. Put a large socket in the bore and replaced the head so the engine was locked. Knocked of the three sections of the roll pin and the pulley undid by hand! Half undid the three set screws on the flywheel so I could get the legs of a side hammer puller underneath. No go, was worried about damaging the threads on the flywheel. Went to see a mate who had 2” long ¼” Whitworth bolts and put these in a four slots attachment I have for the puller. After a lot of effort, it came off and immediately saw the reason why it was on so tight. The surface of the shaft and the hole inside the flywheel seemed to show signs of a seizure, yet the shaft does not rotate inside the hole. I think either there was swarf or similar on/in it during assembly, or a machining flaw and if known, may explain the roll pin.

Initial continuity HT test showed a variable reading, think the black probe was not on a good ground. Have tested again yesterday, both HT and LT resistance is OK. Tested the condenser with a Megger, it failed. I do not use tradition condensers anymore, use a modern polyester film 630v 220nF/0.22uF capacitor. Was actually hoping the coil was duff so I could try again making up a single wire energy transfer coil system. Am still going to do it, but will take off the existing coil, make a former for a new coil, put the old one back on and complete the engine overhaul. Will test the spark from the existing system, then fit the internal coil I will have made and the external one. Then test that system to see if there is an improvement. Have attached the external coil I am going to use. All good fun.

Best wishes,

Grahame.

[sidevalve5]

Hi Baz. Got the flywheel off yesterday, had a right game with it. Think Facebook only allow one photo in a reply to a post, so will send what I have in a succession of replies to illustrate the matters better. Believe the year of manufacture to be 1951 with the H (missing the bottom left leg) after 2A. Do not think the engine has done much work because there is no wear in the bore and what little carbon there was on the piston and head mostly wiped off with a rag. Took the head off, there was no gasket. Do you know if this is correct. I do not think the cowl has ever come off because the bolt threads for the tank straps and carrying handle still had the lime green paint I think Alcon put on at their works. Believe Jap supplied the engine covered in red oxide as it is inside the cowl and some of the cylinder fins. Put a large socket in the bore and replaced the head so the engine was locked. Knocked of the three sections of the roll pin and the pulley undid by hand! Half undid the three set screws on the flywheel so I could get the legs of a side hammer puller underneath. No go, was worried about damaging the threads on the flywheel. Went to see a mate who had 2” long ¼” Whitworth bolts and put these in a four slots attachment I have for the puller. After a lot of effort, it came off and immediately saw the reason why it was on so tight. The surface of the shaft and the hole inside the flywheel seemed to show signs of a seizure, yet the shaft does not rotate inside the hole. I think either there was swarf or similar on/in it during assembly, or a machining flaw and if known, may explain the roll pin. Initial continuity HT test showed a variable reading, think the black probe was not on a good ground. Have tested again yesterday, both HT and LT resistance is OK. Tested the condenser with a Megger, it failed. I do not use tradition condensers anymore, use a modern polyester film 630v 220nF/0.22uF capacitor. Was actually hoping the coil was duff so I could try again making up a single wire energy transfer coil system. Am still going to do it, but will take off the existing coil, make a former for a new coil, put the old one back on and complete the engine overhaul. Will test the spark from the existing system, then fit the internal coil I will have made and the external one. Then test that system to see if there is an improvement. Best wishes, Grahame.

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[sidevalve5]

Many thanks Andy. Am going to have a go at taking the flywheel off at the weekend and will take a picture of the roll pin. It looks like there is a sleeve or spacer behind the pulley and the roll pin would lock it in place. The first numbers on the crankcase are 2AH, which I think means it’s a 2A manufactured in 1951. But the H is higher than the 2A and missing the bottom right leg of the font. Will take a picture of that too. Could you please confirm that the aluminium pulley will be attached to the slotted steel bolt. So all I have to do is lock the engine and undo the bolt. Have a Warrington hammer that fits perfectly inside the slot, so just need to keep it in really tight and turn. Have an attachment to a slide hammer puller that has 4 slots in it, so bolts at both 120 degrees and 180 degrees can fit. It was in the back of my mind I had something buried in a toolbox that would work and just found it yesterday after a rummage. Think in the first instance am going to try to use it as it is similar to JAP’s specialist puller. Did not know it was a straight shaft and key, was under the impression it was a taper shaft. Great to get that info too.

It looks like the engine was supplied to Alcon painted in red oxide and Alcon then covered everything in lime green. The inside of the cowling still has the red oxide paint on it. It does not look like it’s done much work and been kept in the dry, so will be a little surprised if the coil is duff. But until I get the flywheel off and test at the pickup, I will not know. Am actually not bothered if it is as I have been waiting to put an external single wire energy transfer coil onto such an engine. Know the theory, but have not put it into practice and this little JAP is an ideal candidate. Mocked up the coil I have yesterday and it will fit at the end of the fuel tank. Will keep you posted how I get on, but I will not be doing the full overhaul in one hit. Summer is the growing season when I use my machines, winter is tinkering time.

Best wishes and thanks again,

Grahame

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