Cheapo manometer worked

[montmil]

Although I had planned a morning ride to warm up the R65 engine prior to synchronizing the Bings, the steady rain put a stop to that.

So big fans and an open garage door allowed me to safely warm up the engine. I then pulled off the rubber vacuum port caps, hooked up El Cheapo Grande manometer and went to work.

I hung the yardstick manometer on a ladder in a vertical position, then routed the vinyl tubing to miss the hot exhaust pipes.

Previously, I had self-edited Snowbum's carb synching article from twelve pages to six+. Kept what he calls, "the meat". Re-read the key points and got after the carbs. Couple of false starts, but gee whiz... it worked.

Only future mod I would do to the manometer is add a small restriction tube within the 3/16" i.d. tubing -probably close to the vacuum port attach- to help reduce the fluid 'pulses' a bit. I used BMW's 7.5wt fork oil as a fluid medium. It's purple and 'reads' well.

Right now, the bike idles better than it ever has and has lost the slight off-idle stumble that showed up after the full overhaul work.

Monte

[MrRiden]

Wonderful little tool. Curious, did you run the throttle up with the manometer connected? I found that by doing this balance [cable] could be checked at partial throttle as well.
rich

[montmil]

Yes I did, Rich. I also found if you go too far up the rev clock prior to getting everything closely balanced, you can suck that fork oil right into the engine!

Hack Cough  Wheeze

[nhmaf]

I was gonna warn ya about that last week, but forgot.   Those cheap manometers are inexpensive, but very sensitive, and if things are just a bit out of wack, there is the danger of sucking in oil at larger throttle openings..   I like my stainless steel slides - no sucking those babies out! But considerably more expensive ~ $180  - much more than a yard stick, some fork oil, and tubing & clamps.

IT got the job done - and it sounds like they are well balanced now - you'll probably even see a couple MPG improvement in fuel usage.

[steve hawkins]

I used one successfully for ages on my R65 Cafe Racer, but when I fitted it to my R100 it hoovered the fluid up before I had a chance to adjust anything!

I think with the larger capacity machines you have to go for a thicker fluid than what you can get away with on an R65.  The pulses are that much bigger.

I also adjust the higher RPM's by lightly blipping the throttle of idle, at first, doing this can get you in the ball park before fine adjusting on a constant throttle opening.

But then my brother bought a proper carb balancer, so its just too easy to borrow his.

[Landlubber]

If you go to an aquarium place you can get little plastic G clamp thinggys, they are made for restricting the air pumps, very cheapo and clamped in place get rid of the pulses, by squashing the plastic hose almost off, then no funny smoke from the exhausts!

[montmil]

A beautiful Saturday morning. Perfect for a little further carb tweaking with the El Cheapo Grande Manometer.

I had added a short section of vinyl tubing inside the primary 3/16" o.d. vinyl tubing in an effort to reduce the surging/pulsing of the fluid during adjustments to the carbs. A short length of 3/16" O.D. tubing provided a choked-down area that effectively reduced the up & down surging.

I also discovered that I needed to readjust the throttle cable slack as I had developed an unequal tug on the carb's throttle levers. Another important check that I had perhaps not completely confirmed.

The engine runs a bit sweeter now with a smoother idle at 1050 rpm.

During a ten mile ride to warm the engine prior to tuning (very important to get the engine up to full operating temp before tuning the carbs), I had an anxious moment as one jug quit firing. Jeez Louise, what now?

Outta gas, fool! Hello, reserve.  I'm having way too much fun with these motorcycles.   Monte