As luck would have it, in my professional capacity as a shrimp scientist extraordinaire I was able to attend the World Aquaculture Society Conference at Darling Harbour in Sydney this month. I played hookey for an afternoon so I could go around to Jim Eade Motorcycles in Parramatta Road. Bought a new RH Amal carb and conveyed it gingerly back to the lovely Fiji Islands.
Fitted it gently with nuts done up to not-quite close the gap between carb stub and flange (i.e. this time I put my faith in the rubber O-ring to seal any air leaks) then used Loctite Afterlock to stop the barely-fingertight nuts from undoing themselves again. Getting a bit more clever in my old age!
Then I went through the carb set-up and balance sequence. Somehow I fluked it, ‘cos the bike runs fine. Smooth, and powerful.
I need to find a way to take the black magic out of carb balancing and tuning. For me right now, it’s more of an art than a science. But science shall find a way! There’s got to be a technique that can deliver measurable and repeatable results, and take all of the guesswork out of it.
Another popular mod for Bonnies is to convert them to Tiger single-carb heads. A lot of old codgers out there insist that Triumph twins run a lot better on one carb than on two.
But I refuse to give up. If it doesn’t have twin carbs, it’s not a Bonnie. That’s my opinion.
I see that Classic Bike advertises a gadget called a CarbMate MKII. Essentially a vacuum gauge for twins, but one that measures the difference between two sources of vacuum.
Expensive, but what the hell. I’ll be a yuppie and buy one. I’ll report back later.
