Board index Flathead Power-Technical Questions, Answers, and Suggestions Big Twin Flatties air fuel meter

air fuel meter

Moderators: Curt!, Pa

Post Thu Apr 16, 2015 4:57 pm

Posts: 108
even'n folks,this past weekend got the flattie out for a test ride, i installed an air fuel meter with an o2 sensor in the front exhaust. i run a harley cv carb and had trouble dialing it in, i could get it run fairly strong but always felt like it could be more crisp, well i kept playing with the pilot jets only to find out that the needle was what needed the attention. it was lean in this area. with the gauge it becomes no guess work, real time mixture no matter what, just took about a dozen set ups to dial it in. i now understand the interplay of circuts much better than i did before. i take several trips a year and can now have some confidence that if i go lean,...ie intake leak or whatever i will see it on the gauge before i'm sitting along some interstate hundreds of miles from home. if anyone wants more info i would be happy to respond. mark

Post Sun Apr 19, 2015 3:37 pm
GuS

Posts: 368
Location: Bergen, Norway
Mark
In not the kind of person that can hold a scewdriver between my ear an the motor listening to the sound i t makes an determin how to fine tune the carb. I wish i could. Always a lot of trial and erreor. Always want to fine tune more.
So YES this sounds interesting. What kind of sensor, and intrument to read the values? Something you picked of a car?
Please share some more details.

GuS

Post Mon Apr 20, 2015 5:06 pm

Posts: 108
http://www.rbracing-rsr.com/rsrgauge.htm this is the meter i am using, kit comes with a bosch o2 sensor, weld on bung and gauge. made for motorcycles, seems well made. it is narrow band and show mixture in real time. has helped me understand my CV carb circuits and slide needle tapers much better, plus peace of mind that a no lean condition exists. the link above should take you to rb racing, many other interesting items in their product line.....mark

Post Tue Apr 21, 2015 8:53 am
GuS

Posts: 368
Location: Bergen, Norway
Mark
Kind of lost in the past when I asked if you picked it of a car. Of course there are sensors on injection bikes. And bikes have had injection for some years now.. just not the one I have..newest is a ’61 Beemer all-year/all-weather sidecar contraption.
Really interesting. I’ll start saving.
Thanks
GuS


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