Well, On Friday we got Mario's '55 GF on Ray Moore's dyno.
It had done 1,500 miles since I restored (recreated) it.
It had nipped up on the LH pot at only 150 miles, so we wanted a few miles up, before the dyno run.
The LH pipe also showed more discoloration than the right, which had very little.
The dyno run showed that the midrange was lean, and the top end rich.
The air / fuel ratio was very good on the RH pot, but leaner across the range on the LH pot; Josh, I should have used the anti bias spacer!
The needle was already second notch from the top, so we lifted it to the top. Main jet was a 240; we went down to 220.
Timing was 33 degrees BTDC LH, 34 degrees RH.
This was the result:
The carb adjustments were great; we maintained pretty much a constant air / fuel ratio of 12.5 : 1 across the engine speed. The LH pot remained leaner than the RH, but acceptable.
I had slotted the mag mounting holes, and was able to change the timing over a range of 18 degrees.
We tried several settings, from 34 degrees, to 28 degrees, but the best results came from 30 BTDC. This gave the maximum torque figure (152 ft lb), but more importantly the fattest torque curve over the widest rpm range (900 rpm), and at the lowest rpm.
This mirrors the results for my '54 GF and '51 plunger (all three bikes have 356 cams, but Mario's has a monobloc).
Timing was checked with a light, read off a SRM disc on the primary drive. There was only 1/2 degree variance between pots, which is really good.
At idle, the reading was 2 degrees BTDC.
This is the third A10 I have had on the dyno (4 to go, including the alloy head Rockets).
This was the final runs.
This is the results from my '54 GF; the only difference between the bikes is carb (the '54 has a type 6).
The ugly bloke on the left is master mechanic Ray Moore, the much uglier one on the right is Mario (the Italian Stallion).
By golly, the bike sounded beautiful under load at 5,500 rpm; what a bark!
So, what was the end result?
Mario's verdict; "fantastic". It has more power across the rev range, and is smoother.
We took it for a run to Menzies today; 280 km. We couldn't get grin off Mario's face (couldn't keep up with him either; I am still running in the rigid at 50 mph, and he is streaking off in front at 70 mph).
Here we are at the Menzies roadhouse, for breakfast.
Tony is on the left; he rode the Road Rocket. He is in charge of one of our police stations, and normally rides a Kawasaki VN1500 everywhere (Philip Island, etc; he will be at the Albany Ulyssis rally), but likes to ride the BSA(s) at every opportunity (he keeps repeating phrases like "small", "nimble", "good power" "no brakes").
Tony lent me an air mattress cushion; they work; the trip was comfortable - will be buying one!
Richard
