Just caught up with this one Buzzer, another fabulous build and serious engineering involved, popcorn at the ready!
Thanks! Started the engine build… these are simple engines to build, just a couple of points to remember… There is one special bolt in the crankcase that has an oil feed hole in it. Its also much easier to pop the piston into the bore, and then put the pin in, the rings are very fragile (and expensive!) make sure you have some rag in holes though, those pin circlips have a life of their own! in one of the pictures you can see a plate which holds the flywheel… this is necessary as the alternator nut and crank nut are VERY tight and need torqueing to 190 NM. I would like to thank the local council for the steel to make the engine stand. Leaving a large sign in the hedge at the side of the road for 2 years, I felt I had to re-cycle it
Waiting for a few engine parts so I switched onto the hydraulics. Not sure which front callipers to use yet, so I built both sets. Everything was in great condition so I didn’t change the seals as they were all good.
that's what I decided! I wanted the belts and pulleys to be on show, but I am not keen on open belts… all it takes is one stone! I have made these before out of the original covers. Start by cutting holes with a hole saw, and then cut the oval out. for this I use a saw in the dremel but a saw is OK. Then I marked the profile on some 3mm polycarbonate and cut that to shape. With that in the cut out, I drilled some 3mm holes half in the cover half in the poly. the windows are held in with some 3mm flanged bolts, washers and nylock nuts. I did ad a dab of high strength nutlock and some small neoprene washers as well. I then hydrodipped them. I know that fake carbon is not everyone’s thing but I like it, and when covered with a lacquer its VERY durable and UV stable, unlike the real stuff! The actual process is easy, and the film and activator is cheap. link to a video below of how its done.
Polishing day… I did the engine cases a few weeks ago. I then set a side a full day to polish the rest of the alloy… its a dirty, hard, and somewhat dangerous job! the swinging arm took ages! I used to do it in the workshop, but it made such a mess I now do it on the drive. I have a 2.5 HP 3000 RPM motor that I use that is an absolute beast and takes no prisoners if you get it wrong. Its mentally draining to do actually, thinking about the angle you present the item to the wheel each time. I sand everything with 400 Mirka Abranet first (if you have not come across that product its a game changer, you will never use wet and dry again!) I use an 8" closed stitched mop and medium compound, followed by a loose mop with fine compound. I use some very fine compound on the stainless. That evening I had a bath as I was so filthy. I actually used fairy liquid to clean me off as ordinary soap doesn’t touch it. Next day I absolutely ached all over!
the engine parts I had been waiting for came, and I finished off the belt covers. I also made the housing for the hall effect triggers, the most accurate bit of machining I have done in years as I needed to locate the sensors exactly 135 degrees apart. I will post some pictures later on that. But for now here is the engine!
A nice part of the build is when you start to pull it all together. All that preparation of parts for months before all comes together quite quickly.
One of the things that was missing on the bike when I bought it was a gear lever. No problem I though… until I saw the price! so I decided to make one, and while I was on, make it slightly longer to suit my big feet. I took the one off my other bike as a pattern. I milled it out of a solid piece of alloy plate, and then hand filed it all to shape, and gave it a polish, I was quite pleased with the result!
One of the things I wanted on this build was a clean looking rear end. I struggled to find a rear light that was suitable, so in the end I have fitted three 10mm superbrite LED’s as a rear light, and used a resister and diode so its bright and then brighter to act as a stop light.
I have made a few similar Hall Effect ignition pickups in the past and they have worked brilliantly. This is a refinement on those. This time I have used an alloy cam wheel and put the magnets directly into that, rather than use a separate wheel. the magnets are 3mm as opposed to the 4mm ones I have used in the past, lets hope they are OK! I also swapped out the allen bolts for some none magnetic A4 ones just in case it picked those up. Previously I have had a small discrepancy in the timing cylinder to cylinder, which is OK as I can compensate for that in the Ignitech software... But it irritated me that I had to do that! I put it down to my rotary table that is not the best and only measures degrees and its difficult to get the holes for the sensors precisely 135 degrees apart. This this time I borrowed a mates table that is very accurate and can measure to minutes. It was a pleasure to use such a wonderful piece of quality kit! Making the pickup plate took some time, probably the most accurate work I have done in a while! I am not sure i needed the heat sink, but it looked aesthetically pleasing so I used it.
I finished the throttle off... I had to make the adjusters as they needed to be a custom size. I also used cycle gear cable as the nice thing about it is the outer wire is longitudinal, which has several advantages, the one being that you can cut it so the inner liner can extend into the adjusters and into the throttle which makes the entire run of the inner cable within the liner. I was very pleased with the light action, and only a 1/4 of a turn closed to open. We all know a fast action throttle adds 20 BHP ;D I know that I should use suppressed leads, but I prefer to use copper cored ones. they are easy to make up and you can make them to the spot on length. I have had that crimp tool 50 years! one of the things I wanted to do was get rid of the rubber frame bungs… so I turned up some alloy ones. I needed some alloy bar, so I popped into my local metal recyclers… he had several skips of alloy round bar and machined square and oblong billets, all different sizes… many marked on the end with the material specification! They were just about to be taken away so I had to be quick, I really had to restrain myself though, it was like Christmas had come early!
Things don't always go to plan... I tried to starts it... I had a spark, and lots of backfires, but it would not run. I checked a few things and came to the conclusion it was the pickups... I wasn't sure if it was the actual hall sensors, or the magnets and spacing. I decided to try the magnets and spacing first, and it turned out to be that. not sure if it was the strength of the magnets, or the spacing (I suspect it was the spacing) but either way I had to re design the rotor. soon as I did this, it fired up and settled to a nice tickover. I also breathed a sigh of relief as I had put a lot of effort into the exhaust and didn't know what it would sound like! To me it sounded awesome! here is a short video.
the fuel tap proved to be a challenge. It couldn’t go on the tank, but I also didn’t want to on show. In the end I made a small bracket and mounted it out of sight. I popped into the paint supplier where my mate works… he persuaded me to try some new lacquer which he said the customers were raving about… I reluctantly agreed to try it. Although I had prepped the tank, I thought I would try it on the mudguard first… I am glad I did! It was easy enough to spray, and gave a nice gloss from the gun, BUT it took almost two hours before it was dust free… That may be ok in a heated, dust free paint booth, but in my garage its a distinct disadvantage. So its back to what I know and I went back for some of the formula I always use!
Without wanting to detract from your build, that workmate looks like a 1970’s original. I have one the same that my now deceased old man gave me when he emptied his garage before my parents moved into their retirement flat. It’s even has very similar paint spatters too. Nice build again buzzer.
