I have a PClll,Rush 1.75 slipons k&n A/F allfrom fuel motochecked my mufflers ( there not leaking air ) set thottle to 0,,,,semes to be running fine BUT still have poping on decel and only getting about 35miles to a gal should I have it DYNO and whats a good price to have that done ??

 

decel pop is from unburnt fuel in the muffler. You still get some fuel even though you let off the throttel that can escape and cause the decel pop......

 

How do you know it is not leaking air? Did you seal the muffler/exhaust with anti-sieze or high-heat RTC? I have the exact same setup and get 40-50mpg, no decel popping, and probably have the same map you're running. I have modified the map, however, for mileage (leaner primarily in the cruise range).

Under what conditions you're checking mileage is important. If you're checking after a tankful of city riding with lots of cold starts, I wouldn't call your mileage especially bad. If you're getting 35mpg on longer rides with few cold starts, I would say it's time to start tweaking your map for mileage. Jamie's maps are configured more for cooling and performance than mileage, and I find that you can get away with quite a bit of leaning between idle and 2500 RPM and 10% TP. Be careful with 20%, not going leaner than 50% of the original map, and leave above 20% alone. Unless you're in the throttle frequently it won't affect your mileage much, and you'll want to retain these richer values for the times when you really want maximum acceleration.

Try changing all your values from 0 rpm/0% to 3000 rpm/10% to "0". Further, lean 20% from 0 to 3000 RPM to 1/2-2/3 of the original values. Example: If original was "10", change to "5" or "6". Leaning in this way will increase heat, but if you have an oil cooler and use synthetic oil you should be within acceptable limits. If no oil cooler, I wouldn't go this far, but I can't say what might be right for your bike. Mine rarely runs over 210° using this map.

 

[deleted]

 

I just ordered that exact setup from Jamie today. I'd be interested to know how you end up resolving this.

 

And you thought me putting the O2 sensors back in line as a test was ballsy?
Why stop at zeros? Maybe negative values would work; after all, you've got an oil cooler. Hahaha!

Seriously, man, I'd either get a wideband commander or similar before doing much of that. Have you checked your plugs for AL deposits?

 

Check your exhaust flanges. When I got my bike (I'm the third owner) I had some serious popping on decel. When I replaced my stock exhaust with Rinehart TD's, I was able to remove the original exhaust at the cyclinders with my hands -- surprised the nuts had't fallen off. Needless to say the previous owner had not done much maintenance on the bike. After installing my RTD's and PCIII, and being sure everything was good and tight, no popping on decel and bike runs great. Good luck.

 

I sense the tone of a non-believer. I'll also be serious in saying that negative values are not ruled out, but at this point I won't go further without determining the A/F I'm running now, which we've discussed in another thread. On my ride today I managed 50mpg, something that's routine on these rides, which is acceptable and I think near max I might expect for this engine. At least I have heard of few that have managed mileage this high, so I suppose I should be happy. I do favorably recall my old Evo RK that could manage 55-60 mpg on similar rides, though. City mileage with numerous cold starts still sucks, however, and I'm not sure there's an easy fix for that malady.

Yes, I've checked the plugs and they are fine. In fact, I replaced them recently with Autolite 4163's, one heat range colder. I'm getting no detonation or other indication of a too-lean condition, although I did get minimal detonation one day when I tried bumping ignition advance in the cruise range 4°. I quickly reset them to their original values ("0"). Keep in mind that 0's in A/F blocks represent no change from the ECM, and in open-loop mode it is running richer in the cruise range and idle than stock in closed-loop mode. I don't know the exact A/F ratio, but if I was beyond the over-lean threshold there would be performance indicators, like flat spots, detonation, and/or surging--and I have had none of this. I have heard that A/F at idle with O2 eliminators is 12:1 with the value at "0", which is rich enough. I'm not sure what "0" represents in the cruise range, however, but Jamie at Fuel Moto thinks it would be around 14:1.

Jamie at Fuel Moto approves this strategy, BTW, as does DynoJet--as I've discussed it with both of them. If I was running too lean it would also be reflected in oil temperature, and I'm running cooler than the majority of TC96 owners who've quoted their oil temps, even those with coolers. Today with temps in the low 90's (before it climbed to 102° later in the day), my oil temps rose to 200° while moving, up to about 210° in traffic. I didn't even need to toggle my richer map, which is switchable on the fly when needed to cool things down. Another indicator is heat radiated toward the rider, and I'm feeling no discomfort at all from engine heat. This bike is no hotter to the rider than my old Evo was.

 

Oh, I'm most certainly not a disbeliever. A base 14:1 at "cruise" range in open-loop mode sounds reasonable but maybe in stock air-moving-peripheral configuration. With freer-flowing stuff, who knows.

A twin-scan or wideband commander would be neat to own and when I resume positive cash flow I fully intend to invest in one. I believe they're comparable; that they'll log data and such. I'm getting right at 40 mpg average (with maybe 1/3 of the tank being used in-town). I'd like better, but it's better than worse

Keep up the good, informative feedback.

 

A/F of 14:1 stock or with free-flowing peripherals is still 14:1, right?

Can't find any info on the Twin-Scan II. Do you have a link to some info? WBC is neat, but pricey and I'm not sure where I'd mount the gauge. I guess you wouldn't really need to mount the gauge permanently, as once you've dialed it in it shouldn't change much. I still like the idea of buying a Bosch LSU4.2 or similar W/B O2 sensor and using a voltmeter, which using a translation table would indicate A/F ratio. That would be a cheap alternative, but I can't find a small LED display that will show voltage. I wish I was a bit better versed in electronics so I could build an LCD A/F gauge that shows the actual ratio.