22. Ariel Golden Arrow - Finished !!!

Well the final missing part, the electronic ignition kit, finally arrived today and I could see if all of my work has paid off.

In the mean time, I've fitted the fly screen, which I must admit I was a little nervous of. It is basically a curved piece of Perspex and is not pre-drilled. So I mounted the fixing brackets to the handle bars and carefully measured the distance between them. I then stuck broad 2" masking tape across both sides of the screen where the holes approximately had to be. I then held the screen in place and marked through the holes in the fixing brackets, onto the masking tape, where the holes should be.  Thinking about it, it didn't seem sensible to just bolt the Perspex directly to  the metal brackets. I felt that even a small difference in angle or a little bit of over tightening would result in a cracked screen. So I decided to drill the screen large enough to take some wiring grommets and then pass an 8mm bolt through the grommet, with washers each side to fix it to the brackets.

This meant drilling 12mm holes in Perspex and I was pretty sure that if the drill snatched that would be the end of the screen. So I decided to drill a 3mm hole and then increase the drill size by 1mm at a time until I was up to 12mm. By using a pedestal drill and resting the screen on a wooden block I did the most careful drilling I'd done in a long time, but to my relief successful. It was then just a case of fitting the grommets and the stainless bolts and washers.

It then became obvious that the angle of the brackets and the curve of the screen were very different. The answer to this was to twist the brackets in a vice until the angle matched . And there it is perfect.

The only other bit that was to be fitted before I got the electronic ignition was the toolbox lid. This required the bracket that slots through the tool box, to hold it in place and has a threaded boss in the centre to take the chrome fixing screw that holds down the lid. I've had this bracket on order from Draganfly for 2 years and realise that I'm never going to get it. So I decided to have one made. So I did a simple drawing and took it to my friend at Gladex who made me a stainless steel one the next day and surprisingly it fit first time.

So on with the main event! The new electronic ignition kit arrived and, following the instructions, fitted easily. I then placed the spark plugs on top of the cylinder and kicked it over and low and behold two beautiful blue sparks. Then with a 25:1 mixture in the  tank and the plugs back in, I gave it a kick. Nothing!  I tried again. Nothing! Just before disappointment took hold I suddenly remembered, "this bike has an ignition switch ". Idiot!!!
I switched on the ignition and kicked again - - - and it burst into life, wonderful.

OK There was a small problem with the throttle cable sticking, but who cares. That was soon fixed and it was time to take a ride up the car park. I am pleased to say that, at last, it goes as well as it looks. Perfect and ready to show this year.

Well not quite! Three days later I decided to show the Ariel to a friend and guess what? It would not start! After kicking it to death it finally started and I rode it up the car park again and then back into my workshop and stopped it. I then tried to start it again and to my dismay it simply refused to start no matter how many times I kicked it. This was obviously no good if I was going to show it this year so once again I needed to investigate.

I noticed some oil seepage between the cylinder heads and the cylinders and suspected that the heads may not be seating correctly and also I did not trust the rather vague timing instructions issued with the electronic ignition kit. So for the umpteenth time I reluctantly decided to strip the engine again.

Taking the heads off revealed oil seeping down the cylinder head studs. That had to mean that the heads were not sealing against the cylinders. So I decided to have both the cylinder tops and the heads resurfaced. But before removing the cylinders, this was an ideal time to take a serious look at the timing.

With the heads off and the bike in gear, it was easy to rotate the back wheel until the left piston was at top dead centre, as I could now see it. I then took a Lambretta timing disc that I had and stuck it to the end of the crank shaft with blue tac and stuck a pointer to the crank case the same, pointing at 0 degrees. Then by turning the back wheel backwards, beyond 40 degrees, and then forwards to 20 degrees, I now had the engine at exactly 20 degrees before top dead centre. Which is where the spark is supposed to occur.

Now the timing disc could be removed and I could draw my attention to the electronic ignition. The instructions say "Set the magnet, which is on the rotor, in the centre of the green receiver block, which is mounted on the base plate" (Which is where the old points should be). Well that green receiver bock is quite large and roughly in the centre seems pretty slap dash to me. So I tried to figure out how to measure exactly where the spark happens.

Firstly I disconnected the two wires to the green electronic ignition receiver block and put a multi-meter across them and then, with the base plate loose on its screws, rotated the block past the magnet, hoping that the meter (set on Ohms) would register a contact being made. It didn't. So I then turned on the ignition and metered the two wires feeding the block and found that the white wire was carrying 12v. So I reconnected the white wire to the green block and put my meter (the old analogue type), set on 10v, on the output black wire of the green block and earthed the other lead of the meter (Positive Earth). I then rotated the base plate again past the magnet and at one point the needle on the meter gave a sharp flick. I had found the ignition point. Now as the crankshaft rotates anti-clockwise, I rotated the base pate clockwise until I got the flick and then locked it down with the screws. The timing was now exactly 20 degrees before top dead centre and looking at the position of the magnet in relation to the green receiver block, no where near its centre point. In fact I estimate that the original instructions put the timing about 15 degrees out.

So now I could remove the cylinders and send them off to be skimmed. They were back in three days and the engineer informed me that both heads were "wavy" and that one of the cylinders sloped towards one corner. He had to take 5 thou of one side and 6 thou of the other, but they were now back and flat. Now I could reassemble them with new gaskets, top and bottom and torque them down to the correct setting of 18 ft lb.

I also took the opportunity to fit new sealing rings to the exhaust pipes and seal them with some high temperature silicone sealant before tightening the nuts with a "C" spanner. By the way, I've had some spare "C" spanners made out of stainless steel and I'm selling them if you need one?

Well it was time to check the compression again and this time the compression was up on both cylinders and even to 100 psi. So that just left the spark plugs. In my frustration I had been talking to John Ellis, the man who looks after the two stroke spares for the Ariel owner club, (A really knowledgeable man) and he had told me not to bother with any other spark plug make other than Champion. So I threw away my NGK plugs and bought some Champion N4C plugs and set them to the recommended 30 thou gap and fitted them.

So It's time for the moment of truth! Petrol on, Ignition on, no choke, tickle carburettor, open throttle, - - -Kick --- IT GOES first time!   Brilliant.

To make sure that this is not a fluke I switched off and tried it again and it started first time every time. Fantastic. So this time IT REALLY IS FINISHED!!!!!!

Well that's it, I hope you've enjoyed the blog and please drop me an e-mail on hopcroftscoot@gmail.com if I can be of any help. My next two projects are not motorbikes.

16.11.22  THIS BEAUTIFUL ARIEL GOLDEN ARROW IS NOW FOR SALE

CONTACT ME ON: hopcroftscoot@gmail.com

My Other Blogs:
BSA A10 Super Rocket
http://60sclassicmotorbikes.blogspot.co.uk/2012/07/before.html

Miniature Land Rover Defender
http://miniaturelandrover.blogspot.co.uk/2016/02/1-miniature-land-rover-defender-idea.html?view=timeslide

1971 Karmann Ghia Convertible Restoration
http://karmannghiarestoration.blogspot.co.uk

Thanks again for your interest
Kind regards
Kevin Hopcroft

 Copyright K. Hopcroft  22.01.16 All rights reserved

I took the Ariel to its first show on 1st May 2016 and it won "Bike Of The Show" That's a good start to the season

You can contact me on: hopcroftscoot@gmail.com

 My Other Blogs:

1961 BSA A10 Super Rocket Motorcycle:
 https://60sclassicmotorbikes.blogspot.co.uk/2012/07/before.html


Miniature Land Rover Defender:
http://miniaturelandrover.blogspot.co.uk/2016/02/1-miniature-land-rover-defender-idea.html

1971 VW Karmann Ghia Convertible Car: 
http://karmannghiarestoration.blogspot.co.uk/2017/03/1-karmann-ghia-retoration-project.html

Motorcycle Trailers / Caravans:
http://motorcycletrailersandcaravans.blogspot.co.uk/2018/01/1-motorcycle-trailers-problem.html