The Bing Book has always been correct when ever I have used it. With respect to carbs on an R65 vs. an R65LS, I can not speak to that issue from personal experience.

What you are really asking is this: Which is most trustworthy, the book or people ? 😛

In my experience the books published at the time of manufacture, are much more trustworthy than what 35 years of prior owners have been able to conceive and do to save $2.

As the old saying goes: The cheapest thing on a BMW motorcycle is the owner !! 👿

I guess I'm observing that there are 10 different R65s listed with different carbs on each and nothing that says which one is which. I'm trying to determine if one setup delivers better overall performance than the others. I'm not trying to make a silk purse out of a sows ear, but I do want a very smooth running ear. I'm about to do a full rebuild on these carbs and it would seem that would be the perfect time make any effective modifications.

[Least this thread digress into a squabble about the environment, allow me to state that I am all for preserving the environment. No one is suggesting that you should dump your waste oil in the nearest creek or any such rubbish as that. Try to keep in mind that this is a thread about a single motorcycle, out of millions on the road. All our neighbors have "zero turn" lawn mowers with no pollution controls and much larger engines than the one being discussed here.]

1. ► Generally speaking, you'll be better off if you can find the jet sizes noted for the European or pre-EPA American models. European wanted their bikes run their best, like they were designed to run and still use fuel very efficiently. The EPA, on the other hand, doesn't care how an engine runs, hesitates, spits, or coughs, they only care about the mandated levels of various gases. To achieve the EPA goals, fuel ratios were leaned out, making the engines run hotter. So much hotter as the years progressed that air cooling is now a thing of the past.

2. ► Also remember that, say for instance on a 1985 model, ethanol had not yet been introduced into the fuel. You'll probably need to go a bit richer to make up for the ethanol in current day fuels to achieve the same performance.

The Haynes manual is one that lists all jets sizes, both American and European. Bing also has similar information in their manual.

So basically, you want the largest bore carbs with European jet sizes. Generally, if you go from a 30mm carb to a 32mm carb and have no jets, as a starting point you can use the jets from the smaller 30mm carbs.

Additionally, it's not simply the carb bore size, but other restrictions found in the intake and exhaust systems. Replace the air intake snouts with the larger ones from an R100. And fit the less restrictive Mac mufflers.

Hope this helps.

Update,
The Bing book was wrong. It insisted that the carb #s on my bike belong on an LS and listed different #s for my application. I found that my owners handbook says that the carbs are correct. BMW wins that one. After the rebuild, I still had big a mid-range flat spot, so I took a shot in the dark and raised the needles one step. Purrrfect! Plugs look great, runs great and getting mid 40s and up for fuel economy.

I'm trying to determine if one setup delivers better overall performance than the others.

For the best performance, also make sure the intake air is not restricted in anyway. One obvious restriction that may be present is the air filter housing "snorkels". Those are the 2 conical tubes that point forward from the air filter housing. Those come is several sizes, and you want to make sure you have 2 of the largest size offered.

To improve my RS intake, I found a used cover on Ebay complete with 2 large snorkels for ~$15.

Out of curiosity, does realoem show the correct number?

Bob

Out of curiosity, does realoem show the correct number?

Bob