pfg49
XS650 Member
I've just bought a Rickman built from a donor 78 SE. The bloke I bought it from, built it and never rode it, in fact he did 2, and literally never rode either! He likes building bikes, but not riding them. Each to his own I suppose. The engine is bog standard, except for the pipes which have removable baffles, and I'd imagine the baffles will be restrictive.
Having gone round it and done a spanner check to tighten up the loose nuts and bolts, I gave it a blast. It ran very well for about 5 miles, then 1 cylinder started to misfire. Nursed it home, did a few checks and thought it might be the condenser. I was going to buy an electronic system anyway, so I bought a Boyer and fitted it. NO change!! I've changed everything on the ignition, so it must be fuel. Off with the carbs and I found this.
Now the carbs aren't bad, but I will have to buy a new float, and several other bits and pieces including the diaphragms which don't look to stunning, and are a bit hard, so sod the expense, give the cat a goldfish, I'll buy some new carbs. Now my choices are, Chinese Mikuni or Keihin rip-offs, genuine VMs, or something more exotic. For me it's the rip-offs or the genuine VMs.
I had some Chinese Keihins on my 71 BSA Lightning, and my 74 Triumph T150 triple, they worked well, neither set was spot on, but fairly close, but I only got rid of them because I couldn't find anyone to rolling road them. I've read on here about the trials and tribulations connected with the Keihins, and I didn't even know you could get rip-off Mikunis. My questions to the wise and experienced carb swappers on here is, has the build and quality of the Keihins got anybetter since mrriggs marathon struggle, has anyone used the Chinese Mikunis, and finally, as I have a 78 SE engine, do I really need 38s or should I use 34's? I always worry about too big a carburettor on an engine.