Monometers

[dwire]

I've seen such things used on snowmobiles and maybe some old inline 4 import M/C's but I guess just being the dope I am and of course there are no ports on my Bing CV's for any such thing, just do it the only way I ever had known on two cylinder engines; set cables and try and have it so I am in some sort of ballpark (enough for the thing to run lol) and then the rest is all by "ear" and maybe a little seat of the pants as well - but still mostly I am using my ears even while on the thing "seat of panting it..." lol

I am not saying this to knock anyone's techniques here; quite the contrary - I'm actually working toward a question.

For such devices to work properly, would not both cylinders have to "behave" in the same manner? For instance, a slightly burned intake or exhaust valve, worn rings more on one jug than another - you know all the things that could be slightly different from one side to the other of a two cylinder BMW engine. Would not these variances sort of render the devices you guys are speaking of a bit futile? I don't know; I am seriously asking here. I would think these anomalies would show up on such a device, so if that is the case, when you balance them, does it "work right?" I mean, I know without a doubt my two cylinders are not the same - just by counting and recording the turns in and out I've set them for recording purposes as well as if down the line I find they need readjusting when I felt certain they had been performing properly prior - makes me ask myself what has changed in the system if that makes any sense. I get no "answers" other than something has and then start the flowchart of most likely issues...

Anyway I'd be interested in hearing the success stories surrounding these balancing units for a non-freshly rebuilt two cylinder BMW, perhaps I could learn much from this. Thank you in advance.

dwire

[Major Softie]

For such devices to work properly, would not both cylinders have to "behave" in the same manner? For instance, a slightly burned intake or exhaust valve, worn rings more on one jug than another - you know all the things that could be slightly different from one side to the other of a two cylinder BMW engine. Would not these variances sort of render the devices you guys are speaking of a bit futile?

dwire

No, actually, that's exactly what you are compensating for when you balance carbs: the fact that the cylinders are never perfectly the same. It that weren't so, you could actually set the carbs to some identical "spec," and then everything would be perfect. Yes, you are also compensating for the fact that the carbs are not identical, but not just the carbs.

[dwire]

For such devices to work properly, would not both cylinders have to "behave" in the same manner? For instance, a slightly burned intake or exhaust valve, worn rings more on one jug than another - you know all the things that could be slightly different from one side to the other of a two cylinder BMW engine. Would not these variances sort of render the devices you guys are speaking of a bit futile?

dwire

No, actually, that's exactly what you are compensating for when you balance carbs: the fact that the cylinders are never perfectly the same. It that weren't so, you could actually set the carbs to some identical "spec," and then everything would be perfect. Yes, you are also compensating for the fact that the carbs are not identical, but not just the carbs.

Lordy, OK, I need just lay my head down now. I knew that... Was not trying to be smug with users of such things either.

Reality speak is I am a fellow that is always calibrating this and that to standards that are ridiculous at times it seems, yet always seemed simple to dial in my bike or a lawn tractor just from listening, "feeling" and other normal perceptions, not a device. Ironic since I'd worked in calibration labs and such. We had one of those and a mercury vacuum pump that had been in the lab for eons. They got rid of that shortly after I had started realizing if anyone ever tipped that 8 foot board with a u-shaped big old pipe filled with mercury, the entire operation would turn into a super-fund site... lol

[chasbmw]

I use old school mercury filled Morgan carb tunes, not available any more, but the new version uses steel rods in a glass tube and by all accounts gets similar results! Be careful of using 2 guages, they need to be calibrated the same.

I find that the bike tells me when it is right......the most important part of the whole process is getting the throttle cable free play exactly right so when you open the throttle both carbs open at the same time, I can't do this by ear and bing carbs are very sensitive to getting this right.


I'm currently in Trujillo in western Spain, a really unspoilt piece of Medievil Spain associated with both Pisarro and Cervantes. The bike covered around 300 miles of really great 2 lane roads. Running well and at moderate speeds doing almost 50mpg (imperial). Iv just about finished the 1/2 litre of red wine that comes with the meal. Off to Zamora tomorrow, more of the same with any luck