Topic: '79 CB650 PD51A carbs

[spitfire79]

Hi guys,
Hope you are all good
Quick intelligence gathering here, sure this question has been asked a million times.

I have a '79 CB650 with the PD51A carbs set, but I also bought a set of PD41B carbs from a '77 CB750F awhile back.

Apart from the small misalignment , should the 750 carbs work, or do i just cannibalize the pd41 carbs for the jets, and put it over onto the cb650 carbs ?

Thanks

[fizzlebottom]

What's wrong with the carbs that came with the bike?

[spitfire79]

Hey,nothing wrong with the carbs I currently have one.

And the 650 still has plenty of kick for an old lady, just thought I might try and get a bit more out of her, without having to go to complete extremes

[fizzlebottom]

I have an '82, so I have experience with the CV carbs instead of PD carbs. You'd be going from #90 to #105 mains which is 6 sizes up. Someone more well versed in PD carbs needs to pipe up, but I think you would be running overly rich and end up with some very wet plugs.

If its running right, don't change anything.

[spitfire79]

That makes sense.
Im not planning on running the silencers..Yes I know it is going to be loud, but that is sort of the point. In South Africa, you need to let these taxi drivers you are close. Last time I started up without the silencers, about halfway through the rev range she was starting to choke up, like the bike was not getting enough fuel, sort of sputtering to a stall. Not sure if was due to lack of back pressure from the silencers. Ill give it a go again soon enough
I see what I can find out about adjustments on the PD carbs