The New And Improved Unofficial R65 Forum V2
Technical Discussion => BMW Technical Q&A, Primarily R65 => Topic started by: goathands on July 22, 2012, 10:32:15 AM
-
Hi All,
I need to balance my carburetors and am wondering if there is a preferred carburetor balancing tool on the market that works well with the R 65. Also, any tips for achieving good balance would be appreciated.
Thanks,
Jim
-
I've had some luck using the carb shorting tools from northwoods airheads...http://www.northwoodsairheads.com/index.html.
The whole process is outlined on snowbums site but for the most part, adjust the idle jets first, then short out each cylinder for a few secs at a time listening and feeling to the firing one. Then adjust the idle stops so that the 'feel' on each side matches.
It took me a bit to figure out the bike idles great now. Also, you shouldn't do this process for more than 5 min or so without stopping, taking off the shorting tools, and going on a ride to cool the engine.
Hope that helps....
Josh
-
I and many others use a home made yard stick manometer filled with ATF. Anything you can buy is unlikely to be as sensitive.
I use the manometer for checking balance at idle and at 1500 RPM. I can accept that the plug shorting method is ultimately more of a real test of balance so I use that after a vacuum balance for a final check on idle mixture strength side to side. In fact you can't adjust mixture strength with a manometer so you have to do it by ear.
Snowbums write up is lengthy but worth the effort.
-
You can build the ghetto-balancer for a few dollars - a yard stick, some clear vinyl tubing and a few screw clamps and a partial bottle of auto transmission fluid... or you can go for the pricey, (but IMHO) ultimate blancing tool - the Morgan Carbtune. When using the Morgan Carbtune though, one has to hang it upside down when working on the R65 and other airheads - it changes the scale/sensitivity as the vacuum is quite weak on these as compared to that on many of the slide carbs on Japanese bikes....
I really like my Morgan - it cannot leak, it wont get its fluid sucked into the carb that is out of balance and I can use it on 1, 2,3, or 4 cylinder engines (I have the 4 slide unit, but they also sell a 2 )
-
I'm one of those cheap guys who like to live on the edge of sucking ATF into their bikes. :)
Works great on the big bikes too!
(https://bmwr65.org/smf/proxy.php?request=http%3A%2F%2Ftfogle.smugmug.com%2FMotorcycles%2FBikes-in-Pieces%2FMaint-033%2F546064202_pxQdS-XL.jpg&hash=c1b01440313fb5fce4d52ca7ffb2d891b41789f4)
-
Nice to see the high tech bikes can still use low tech measuring tools.
On a routine tune up the balance is not that far off so I've never even come close to sucking the ATF into the carbs. When the vacuum ports start flowing ATF instead of air I imagine the flow rate would slow down dramatically and I doubt burning ATF in small quantities would do any great harm.
-
... and I doubt burning ATF in small quantities would do any great harm.
As someone whom has tweaked badly out of synch Bing CVs and did a bit of "fogging for mosquitos" along the way, there was no harm done to the bike and the mandatory shop fan blowing down the bike's longitudinal axis quickly cleared the air.
I still enjoy using my Ghetto-Mano. You sure can't beat the price. [smiley=thumbup.gif]
-
I once tried to be fast enough to connect one side then the other with the engine running!! Shut her down before the ATF went into the carb. Do not imagine any harm if it did.
Of course I was using the factory unauthorized version of the carb balancer.
-
Thanks for the all suggestions. It's reassuring to hear that the DIY manometers are sensitive enough to dial in the balance. I'd forgotten about Snowbum's site, Thanks for the reminder.