hi I am looking for a pre 1918 steering stem . I am hope in that some has one in the shed that they do not need .

thanks carl.

Eric

Do you still have your gearbox apart and if so could you take a photograph of the kick start return spring. I did post a request for help a few weeks back as the new spring I fitted to my Aero did not fully return the kick start lever. I have now established that the new spring I got from club spares is for a 3 speed box and not the 4 speed. Unfortunately they don't hold stcck of any other spring for the Aero and the problem is further complicated by the fact that the club does not have an orginal drawing of the 4 speed spring. Before I or the club get some made I would like to make sure that we know what the correct spring looks like. The broken one I removed from my gearbox again does not appear to be correct and probably why it failed. Photographs of the spring I got from club spares and the broken spring are attached to my original post. Any help will be greatly appreciated.

Roy

Hi Eddie,

Thanks for that info. I turned the ignition timing round so to speak as you described. The engine fired on the rear cylinder about 5 times with plenty of oil smoke before stopping. I didnt have time to do any more today, but I think thats a step in the right direction.

Thanks for the warning about weak methanol mixtures. I am interested in the units of measurements for jet sized. Ive seen some Douglas data which says the jet sizes were 100 to 120 for petrol and 35% larger for methanol. I assume that the numbers stamped on my jets are the same units as these ones, but have no idea how those figures relate  to the hole size, or whether the sizes you use are on the same scale, and what sizes these hles are?

I didnt check the timing of the valve closing point, but will do so tomorrow, I also plan to double check everything again and get the engine running properly, At this stage I only plan to get it idling. I will need to get some proper head gaskets made and then fettle it to start producing power and then put it in the chassis when it comes back from Avit with its mounting kit installed.

Thanks Eddie

The engine is now complete and ready to be started. The carbs have been fitted, an under magneto inspection carried out, the valve clearances set and the valve and ignition timing set. So why wont it run? TBH I'm hoping some of you might have some ideas!

To put some meat on the bones. My inspection of the camshaft etc showed that there was no significant end float on the cam and the cam followers seemed to be running in the centre of the cam lobes and the cam drive gear was meshed in the middle of the idler gear. I couldnt make any meaningful measurement of the cam base circle though.

I timed the valves using my 360 deg timing disc on the flywheel rotating anti clock wise looking at the flywheel, so the inlet just starts to open at 10 deg BTDC. I timed the ignition so that the contact breaker is just opening at 37 deg BTDC on the front cylinder with the rear cylinder valves "rocking"

The magneto has contact breaker base plate marked with a cast L. The magneto rotates clockwise when the engine turns anti clockwise. The stud is opposite the front cylinder. I am not certain that the slip ring is the correct one, but it was recently professionally refurbished. This set up is pictured in the photos posted below.

Both spark plugs had good healthy spark when the engine was turned overtuned over with the plugs removed. The plugs are one NOS Champion COM6 and one used Champion COM5 cleaned and regapped. The gaps are around 12 thou. The contact breaker points gap is 11 thou fully open, and the opening point found when a 2 thou feeler gauge between the points is released.

The engine is running on methanol. The carbs are AMAL/AMAC type M's (I think). I have cleaned, readjusted them and blown through all the various orrifices. Everything runs freely in them, The jets are 150 front, 140 rear and the engine is fitted with domed topped pistons. CR measures at 10.1

When the engine is turned over with the plugs fitted I get good compressions in both cyliders, and I can see vapour being blown out of the exhaust ports. Apart from the occassional lone cylinder firing the engine wont start. I am turning it over anti clockwise with an electric drill on the flyweel nut. I have tried spraying Bradex Starting fluid and putting small amounts of methanol into the combstion chambers through the plug holes (on seperate occasions). Ive tried advancing and retarding the ignition at the magneto, opening the throttles. All to no avail!

I attach below a couple of pics of the magneto. The first one is of the engine at TDC with the rear valves rocking.