Miles By Motorcycle
established 11 years ago
Air fuel mixture and monitoring it with gauges?Subscribe to this blog RSS Feed
    You must be logged in and belong to this group to post to this forum.
    1 of 8
    6 years ago
    2 of 8
    6 years ago
    sorry for the double post I kind of screwed that up but I'm not very phone friendly and that's all I have to get online with sorry

     anyway my idea that just popped into my head is that I was replacing an O2 sensor on my girlfriend's right hand drive jeep and I was thinking you know the air-fuel mixture is monitored by O2 sensors that I don't know about newer bikes but my bike has no sensor that does that but I remember when I was building up an scca race car out of a Ford Focus RS that after we got so much stuff done to monitor the air fuel mixture ratio we bought a f meter and all it did was drill a hole in the exhaust weld the tap it on and then stick the little sensor in and it ran straight to the gauge and it would have a range that was telling you if you're running rich efficient or lean and it was a standalone system that was very small the gauge was fairly inexpensive.

     so having the flat spot in my throttle which was the original thread I decided join the form for is that would it be practical to use one of the stand alone air fuel mixture gauges in a motorcycle since that it monitors the exhaust gas itself in determines if there's excess or not enough of certain experiments into the exhaust stream whether it's running rich or lean because these gauges can be had for less than $30 all they do is hook up straight to the battery and a cable runs down to where you put it into the exhaust which I thought maybe right before the muffler would be a good place to put it in and monitor the air-fuel mixture at all points throughout the RPM range on a car why wouldn't they work for motorcycles?

     this might be unnecessary for daily driving but it may be an appropriate tool to diagnose lean or Rich conditions just by hooking it up driving the bike and watching the gauge and then after you're done if you don't wish to keep the gauge on the bike you could always just remove it and plug the tappet hole in the exhaust.

     if nobody knows what I'm talking about just Google air fuel mixture gauges and it will pop up they're just a little set of green red and yellow lights that go back and forth and it gives you a reading if you're rich lean or ideal.

     my basic training fight on this idea was that if you're having issues with your motorcycle such as I am with a flat spot at 68000 RPM it would tell you whether or not you're rich or lean doesn't mean that it would take the accuracy of having the synchronization of carburetor setup properly but it would give you an idea of the overall running condition and possibly a direction to start heading during Diagnostics or fiddling to get performance or reliability or drivability out of your motorcycle.

     maybe this is a dumb idea and if it is somebody slap me because I don't know girlfriend does that a lot but it was just a thought and I would like some input on whether or not it would be a good or bad or meaningless task to accomplish.

     but I'll go ahead and apologize now for double post excessive threads and really long posts because I use text to talk and I don't realize how long my texts are being by the time I post them so I apologize in advance but any ideas on this matter would be greatly appreciated like I said I'm new to motorcycles as far as owning and working on my own even though I've written motorcycles a long time my daddy always took care of it when I was little but now I'm 33 and bought my first street bike just a couple of weeks ago so 15 years out of the loop and now with a new bike and the want to fiddle and Tinker has all these ideas racing through my head.

     anyway thanks
     Mike Berry
    3 of 8
    6 years ago
    huh. That's an interesting idea. I haven't seen that done but it does seem to make sense.
    4 of 8
    6 years ago
    Link #54741
    6 years ago

    JEGS Performance Products 41417: Air/Fuel Ratio Gauge LED Digital | JEGS

    Buy JEGS Performance Products 41417 at JEGS: JEGS Performance Products Air/Fuel Ratio Gauge LED Digital. Guaranteed lowest price!
     this is kind of what I'm talking about this particular one is one that I used back in the day but there are so much prettier nicer ones that are smaller for about $50 the one shown is approximately 30 but you still need an O2 sensor to run it but they work perfectly fine in carbureted and and fuel injected
    5 of 8
    6 years ago
    This is certainly an interesting idea/approach.

    You could create a tap (near the exhaust header--you'd want a flat plug that doesn't interfere with the exhaust flow for use when you're not tuning) and stick an O2 sensor in there, attach a gauge to it, and then run the bike up to your flat spot under load and see what you get.

    Assuming you're running a carb, you could then try to adjust the circuit in question.

    Not knowing the specifics of your bike, off the top of my head, my guess would be that it's going to be your needle jet (midrange, 1/4 to 3/4 throttle) or main jet (usually 3/4 to WOT), or more problematically, at the transition between the two...
    6 of 8
    6 years ago
    it seems to be while accellerating from about 6000rpm but when at 3quarter throttle rolling to wot.
    but when running just open headder with the collector and a 2.125" turndown it all but dissapeared. Along with strong rich smell i think it was running rich.

     which when I put all the evidence together accept the fact that I haven't been able to pull the tank and get to the air filter yet makes me think the bike is running rich completely but especially up in the upper circuits so with a Open Exhaust it tends to lean bikes out and flat spot goes away I might also be looking at a partially clogged air filter because there's no telling and I haven't been able to get to it yet but if this is the case and I'll confirm it with a plug chop possibly the O2 sensor I had in mind it might be beneficial to the bike to just put for cone filters on the carburetors and run and more or less less restrictive exhaust...
     I do know that this bike was tuned in the area of the state that I'm from here in North Carolina originally the bike was tuned and ran fine when it was fall and at elevation a thousand 2500 feet lower than where I'm at therefore my reasoning being cool denser air requiring a rich fuel mixture than higher elevation where the air is thinner
    7 of 8
    6 years ago
    Redd from the Upstate of SC here . 
    AS to the o2 gauge insall , this is reallly old news . Back around 1982 Hot Rod magazine was installing a sensor and they recorded the readings using a voltmeter which then correlated with a chart , the readings gave a mixture content . 
    I have the story buried somewhere in  my 'tech articles ' scrap book .
    8 of 8
    6 years ago
    I know that using O2 sensors and monitoring air fuel mixtures electronically is nothing new but the fact you can do it for $30 and a tiny little electronic gauge with the flip of a switch was where I was going with that

     kind of just seem like it would make diagnosing tuning issues a little easier