I have been looking for better carburetors for 1970 BMW R60/5. It looks as thought the best choice is the Dual Mikuni VM28 carburetor kit (MPN:SMC-BMWr60) from SpeedMotoCo in Oregon. I have been told that this kit includes all the proper jets, needles and slide. I believe the throttle cables will also have to be replaced or modified somehow. The air intake tubes will have to modified in order to use the the existing BMW air-box setup to accommodate the new carbs. From what I can find with a Google search, these are the proper jets and adjustments...
Main Jet: #150-#160
Pilot Jet: #35-#40
Needle Jet: 159 P-8
Jet Needle: 5DP7
Slide: 2.5
Air Screw: 1-1.5 turns out from fully seated
I don't have good communication with SpeedMotoCo. Does anyone know of someone with these Mikuni VM28 carburetors on an R60/5 bike? A point in the right direction would be nice or a good photo of an R60 with the Mikuni VM28 carburetors on the bike. I have seen R75/5 airheads with this properly installed, but the the R60 is a different installation.
The following is information from Google AI...
"For a BMW R60/5, the most popular and highly recommended upgrade is a dual Mikuni VM28 carburetor kit, offering significantly better throttle response, easier starting, improved power, and stable tuning compared to the original Bings, though it requires proper tuning and potentially minor modifications for fitment. While original Bing carburetors can be rebuilt, the Mikuni conversion is considered a transformative upgrade for performance and reliability on these classic "airhead" BMWs."
The following is information from Google AI...
"For a BMW R60/5, the most popular and highly recommended upgrade is a dual Mikuni VM28 carburetor kit, offering significantly better throttle response, easier starting, improved power, and stable tuning compared to the original Bings, though it requires proper tuning and potentially minor modifications for fitment. While original Bing carburetors can be rebuilt, the Mikuni conversion is considered a transformative upgrade for performance and reliability on these classic "airhead" BMWs."
Any info from AI is proabably worth what you paid for it. I highly doubt that new carbs for an over-weight 600 is going to be exactly "transformative".
Still, it got this data from somewhere. Keep looking.Â
Owning an old Airhead is easy.
Keeping an old Airhead running great is the true test.
Well I did install the electronic ignition from EME. On the "over-weight 600" and it made a notable difference. According to EME, this adds two horsepower as measured on a dynamometer. That doesn't sound like much, but when you only have about 38-40hp, that really helps. Plus gives you perfect timing. If (and that may be a big if) the Mikuni 28's raise your horsepower an additional 4 to 5 horsepower (as claimed) this would bring it close to the horsepower of a BMW R75/5. Not bad. In addition the Mikini 28's "should" improve starting and irregular idle. So yes, I think I will keep looking.Â
Thanks for the response.
I went through this thought process on carbs earlier this fall and decided to stick with my Bings. I just got them back from being rebuilt by Charlie at Bing Agency. I've heard that the Mikuni's offer increased performance, but I gotta trust the original engineers that chose a CV carb set-up in the first place. I'm having this same issue with ignition; when and what to upgrade and if its worth it in the long run. Â
In addition the Mikini 28's "should" improve starting and irregular idle. So yes, I think I will keep looking.Â
Thanks for the response.
There is a company called Sudco that sold these Mikuni conversion kits. You might look there too.Â
https://www.sudco.com/index.html
Owning an old Airhead is easy.
Keeping an old Airhead running great is the true test.
Advertisement
