The second rebuild pt3
So now the cases are back together (again) and in the frame. The crank was lightened and balanced to the rods and pistons to a balance factor of 85% by Chris Applebee. A three piece timing side roller bearing is fitted to cope with the half race T120 exhaust cam. The cylinder head has come back from Len at the Cylinderhead Shop, having been gas flowed and fitted with 1mm larger inlet valves. A 34mm Mikuni carburettor is fitted along with a custom head steady and carb steady bracket.
The bit I hate most, making up a wiring loom, is tested out and all is connected. Tri-spark ignition is employed. The hydraulic clutch conversion from LP Williams is bled, along with the early Suzuki Katana front brake, and all of the covers are bolted on.
The tank and mudguards were painted a lovely British Racing Green by Andy at Art Motorcycles in Ashford, Kent and the newly upholstered seat goes on too. It's finally looking like a motorcycle!
An oil filter is added for peace of mind and the various black braided hoses are fitted. The oil tank, gearbox and chaincase are filled with the required grade of oil. Unleaded petrol goes in the tank with some additive (I didn't go down the unleaded valve seat route as the limited mileage I will be doing didn't really justify the extra cost).
A few adjustments were needed in order to align the gearbox and wheel sprockets (using a special laser tool) then all of the engine mounting bolts are torqued up.
One important finishing job that had to look right is the exhaust. It's the crowning glory on any motorbike and often on specials they look like an ill fitting afterthought, made up of odd bits of tubing and various left over metal strips to hold it all on. A bespoke stainless system (not including silencer) was going to cost me in excess of £350 (plus £50 for polishing) and I was fast running out of cash. I quite fancied the look of TT120 pipes, so I eventually plumped for a Unity Equipe 2 into 1 exhaust system which has a similar style. I had no way of knowing if it fitted. When it arrived I offered it up. It's a four piece system (two down pipes, a collector box and final s-bend to the silencer). It was way too long! However, crucially the down pipes and collector box cleared the frame. After shortening the pipes and s-bend, in several stages, I managed to get them to fit snuggly. The result is, to my mind, a system that is visually right and looks purpose made for the bike.
Better quality stainless steel exhaust roses were sourced from the States, along with a set of p-clamps to hold the pipes securely in position.
And the job was done!
The question now is will she start, run, change gear, stop, not leak oil(!) and do all the things she should?
So, one sunny 2017 October day I decided I would have to take the plunge and see if she would start, or at least fire. I had visions of repeatedly kicking down on the starter until I ran out of puff or my leg fell off, or of the engine kicking back and me breaking a kneecap on the handlebars!
So, petrol on, choke on, ignition on, get the engine onto the compression and a good hard push on the kickstart lever.
Unbelievably she started first kick and roared into life!
I couldn't believe it. I warmed the engine up before taking off the choke and adjusting the idle. After what seemed an age waiting for the oil to return it finally starting sputtering back into the tank before settling down to a good flow.
So now begins the tweaking. The engine hesitates or 'bogs' if the throttle is snapped open, so a bit of re-jetting is required. I have changed jets and throttle valve once, but it still needs improvement.
I need to re-check the valve clearances as the head is re-torqued while tuning/running in.
The only downside is that winter has arrived and now the bike will lay up until warmer weather arrives, so I'll have to wait until next year before I can get an MOT, take it out on the road and give a final overview on how it goes.
In the meantime I'm slowly gathering parts for a TRIBSA MK2, this time with a T150 Trident engine! Watch this space...