carbs rubber inlets

Hi again everyone yet another Q can anyone give me any info on mk 1 concentric carbs like suitable jetting and sizing I am not bothered about fuel economy just the torque and what about some of the rubber mounted carbs I have seen are these kits that can bought or is it make it yourself only, the pre unit engine will have a 1971 splayed bonnie head, 750 morgo barrels, E3134 cams, R followers it is on a one piece big bearing crank, 9.5--1 compression, and I think that is about it, many thanks and happy new year everyone Chris

chrisf1 said:

Hi again everyone yet another Q can anyone give me any info on mk 1 concentric carbs like suitable jetting and sizing I am not bothered about fuel economy just the torque and what about some of the rubber mounted carbs I have seen are these kits that can bought or is it make it yourself only, the pre unit engine will have a 1971 splayed bonnie head, 750 morgo barrels, E3134 cams, R followers it is on a one piece big bearing crank, 9.5--1 compression, and I think that is about it, many thanks and happy new year everyone Chris

Click to expand...

The spec you describe is quite 'tame' to be honest, but will make a nice streetable motor that should be tractable yet happy to rev to 7,000rpm (on occasions).

I'd use 32mm and taper the inlet stubs to match the head.

My guesstimated starting point for carbs would be: #3 slide, 106 needle jet, 'standard' needle, and probably a 220 or 240 main jet. A lot depends on your exhaust pipe and carb intake choice though.

Regarding the rubber mounting components, although you didn't seem to 'gel' with him previously, Dave Degens will have all this stuff in stock. He'll also be able to offer FAR more qualified suggestions re carb settings (and everything else) too!

Sorry should have said exhausts are swept backs and goldies thanks for the advice , I did not want a racer the bike needs to ride well and hopefully reliable but I would be surprised if it is ridden 300 miles per year in case something happens to it thanks again Chris

chrisf1 said:

Sorry should have said exhausts are swept backs and goldies thanks for the advice , I did not want a racer the bike needs to ride well and hopefully reliable but I would be surprised if it is ridden 300 miles per year in case something happens to it thanks again Chris

Click to expand...

Goldie cans are good. Just make sure they have the proper Goldie pattern 'off set' internal baffle and not some other concoction!