/2 type 120 carb difficulties

[Slash2rider]

You can use spark plugs for the rev range you ride and you don't ride on iddle circuit also with modern petrol and well set carbs usually new spark plugs stay white for hundreds of miles unless you set carbs to reach.My experience based on seven classics in the garage.

[fossilfuel]

...it will definitely come through the cover hole: just talk nice to it!..
You don't need the tab if you realize it's just to index the cover to the correct place on the carb: you can see where the tab broke off, and the slot in the carb where it should fit...

Thanks R68 and schrader7032.... with a little more confidence based on your guidance, I got the cables out

New ones from VintageBeemer parts are on the way!! Love this site and thanks for the help....i'll be back with more dumb questions, Im'm sure

-mark

[Worleybird89]

Duane Ausherman method: Dead end?

I had a few minutes after work today, so I took a stab at dialing in my R60/2. Near the end of Duane's writeup, there is a section with the heading "Idle air mixture adjustment" that continues as follows:

Don’t be concerned if your carb requires a different setting than some authority dictates. The main thing to know is that you should find 2 things. The idle air adjustment should have a peak rpm setting.
1. If you adjust the screw more, the rpm starts dropping.
2. If you adjust it out more than the max rpm, it should again drop in rpm. If you find that the best rpm is with the screw all the way in, then you have a problem that needs attention.

Well... with my initial attempt at this method, I found #2. So apparently I have a problem that needs attention? What could that be??? Something beyond the carbs and/or fuel supply system? Vacuum leak between the carbs and heads? I will test for that next.

I am going to try again, hopefully this Saturday, when I will have more time. If I can't get past this, I will try removing and cleaning the idle jets again. If that doesn't work, maybe I will just order new idle jets from Bing. I mentioned in my R27 thread that I've done a complete rebuild of that carb, including jets and needles, and it's giving me bigger fits than the R60 carbs.

[Worleybird89]

Update: Going back to the beginning of my problems, which started when my R60 sat for too long with ethanol gas in the tank (Covid shutdown of 2020), I decided to check the petcock. I removed, disassembled, cleaned, and reinstalled it, and fuel flow to the carbs is much better. I was worried the carbs were starving for fuel. After getting everything put back together and refilling the tank with gas, she fired up on the first kick! This is progress, but I'm still not there. Went back to the Ausherman method and I am still getting the best/fastest idle with the mixture screws all the way in. Starting over at 1.5 turns out from stop, I ended up at half a turn out from stop on both sides, then backing off the idle stop screws to get the idle back down, then try again to adjust idle mixture. It still idles best, all the way in. For now, I just set it at half a turn out and compensate with idle stop screws. I did the vacuum leak check with starter fluid spayed around intake gaskets. No change to RPM, so no leaks. I have not messed with anything past the carbs since the idle problems started, except for new spark plugs, which did not make a significant difference. I have not check timing, the centrifugal advance, valve lash, etc., but my logic is, she ran fine before setting up too long, so the issue had to be fuel related. 1627 miles since restoration by Vech at Benchmark works around 2005. About 200 miles since I got her in 2018 and most of that was before Covid 2020.

Currently, she is running okay. I get no hesitation when opening the throttle. She comes back down to idle pretty quick after revving. I am getting some popping in the exhaust (both sides) when coming back to idle after revving, so I know something is still off.

Any suggestions on what to try next?