Dazed & Confused by Clymer's

[Altritter]

Editorial Comment: There's something about the BMW Motorrad experience that can drive a sane person loony, and it seems to leach into the aftermarket environment.  :-?

Background: I haven't ridden much in a while. Started out with eye problems a couple years ago. Got those fixed, then weather (both summer and winter) went to crap. In addition, there are some safety farkles (such as new tires, lighting upgrades, etc.) that have had to be deferred due to a confluence of final crunch of support expenses for offspring, insurance-company betrayal of health care expenses, etc. There's more, but I'm not seeking pity.

I've tried to ride. There have been some weekend mornings when I've gotten quietly out of bed early and headed toward the garage to armor up to risk death or physical incapacitation in the chaos of Northern Virginia weekend traffic, only to be captured by the big hook before I can reach the door, followed by being confronted by "stat" additions to the endless Honeydo List. (In this neighborhood, any weekend ride beginning after 9 a.m. is not pleasure, but punishment instead.)

Result: Despite a double shot of stabilizer in the fuel and starting up the 65 whenever possible, my Bings are bunged. I can start the bike, and it will idle, but even after it's fully warmed, the only way I can prevent stalling out when I twist the throttle grip is to apply half-choke, and even then, the bike protests above 4K rpm. The dread carb gumout monster has gotten me! It's serious enough that I'm not sure I can ride the bike safely to the nearest reputable indie BMW cycle repair shop, about 15 miles away in Alexandria, in the maw of the NoVA traffic beast. (The alternatives are another reputable indie about 25 miles away, and dealers in DC (~30 miles), Virginia (50 miles) and Maryland (50 miles).) Though I have towing coverage through both AAA and BMWMOA, I want to use it as last resort. I have neither the capability, the skill, nor the courage to load my bike into the back of a pickup to carry it to a shop. (Our 4-wheelers don't even have a trailer hitch—I had enough of that in the Army!)

My cage repair shop-owning friend (who rides an R90-6, Triumph, Suzuki 650, and Honda super-scoot) thinks I can pop the carb bowls, clean the needle and jets, and get the bike in condition to ride to the shop. Dutifully, I went to the nearest indie repair shop yesterday and bought a full gaket/O-ring carb cleaning kit, plus two additional bowl gaskets, in case I screw up. Then I consulted Clymer.

It required a lot of reading Clymer to determine which of the 6 Bing carburetors might have been installed on a 1981 R65 (Type 64-3, right?)

The problem: Clymer is contradictory regarding the means of cleaning the parts. The following are direct quotes from p.335 of my Clymer manual, purporting to cover BMW R90/5 through R100/PD, 1970-1996:

"Motorcycle carburetors have much smaller air and fuel passages than automotive carburetors. For this reason, soaking the carburetor parts in an automotive type carburetor cleaner is not recommended." (Good reasons follow, stating that motorcycle carbs have corrosion-inhibiting coatings that can be removed by the cleaners, then redeposited into passages, clogging them further.)

Then in the next paragraph: "Many good aerosol carburetor cleaners (i.e., Zep Choke and Carburetor Cleaner) can help remove any residue not removed with the solvent."

Does this mean that some carb cleaners are OK, but others are not? If so, what's the discriminator that permits us BMW folks to pick the "good" products & reject the "bad?" Spray carb cleaners are OK, but an industrial-strength "dunk and soak" (without disassembling the carb) is not?

I've been around automotives most of my life, and I can read and think (I think—but that's Descartes, so let's not go there), but I still need help.

Any thoughts?

TIA,
John

[Justin B.]

The only thing that's worth a crap is Berryman's B-12 - keep it outa your eyes!

[nhmaf]

You can use whatever carb cleaners you like on those carbs.   The B-12 stuff is quite potent, so be sure to have ventilation and take precautions.   Now, a number of carb cleaners WILL cause things like seals and o-rings to swell, to the key thing to remember is to NOT get the carb cleaner on the NEW rubber bits when you are trying to put things back together, as bits like the small o-rings can swell and no longer fit properly.  So, you could:

1.  Try some carb cleaners without fully dismantling the carbs - just clean out the bowls and maybe remove the jets to clean then separately, rinse them off or dry off and reassemble - you might be lucky and not have to go in further.

2.  If that doesn't work, you can dive into carb disassembly, remove the rubber diaphragms (check to make sure they are not torn, punctured, spindled or mutilated - even fairly tiny holes can cause problems) and expect to replace all the little o-ring parts with the new ones.  Clean all the metal bits well and rinse or blow dry before fitting with the new rubber bits.   Do just ONE carb (left or right) at a time to avoid mixing up the parts - some parts are "handed" and some are not, and they all appear the same when laying on a table top!!

[Ptech]

I just rebuilt the bings on my "sleeping beauty" R65LS and after disassembly put all but the carburetor body in a carburetor dip cleaner.  There was no coating on the parts.  I didn't put the body in there as there is a rubber o-ring on the throttle shaft which I didn't want to remove.  The body I cleaned with NAPA throttle body cleaner (although I agree with Justin that the B-12 is best, the NAPA is what I had at hand.  If you disassemble the enricher make careful note of the disc orientation on the shaft.  Better yet, photograph it before you disassemble it.  I would also screw the idle mixture against the stop (gently) and count the revolutions before removing it.  This will get you closer to being right when you reassemble it.  As nhmaf previously stated, do one carb at a time.
HTH
Pat

[Semper Gumby]

Get the Bing Agency's carb manual.  It will tell you everything you ever wanted to know (about Bings).

 [smiley=bmw_smiley.gif]

(tweek tweek tweek)