| Author | Message | ||
     Maul |
Hey guys. I just returned from a free dyno run at the local Yamaha dealer. My 1125R ran a disappointing 113 RWHP. The technician said the bike was running very lean through most of the rpm range. I have an early version of the EBR race ecm for pump gas, and I have a Jardine RT5 exhaust. I had absolutely zero issues with this set up until recently when I noticed the lean chugging between 3 and 5 thousand rpms. Any ideas as to why all of a sudden she would go lean on me? I am thinking about getting the EBR ecm tuned for the Jardine. | ||
| Dannybuell |
vacuum leaks can make an engine run lean. | ||
| Maul |
Thanks Danny. How would I troubleshoot that? | ||
| Dannybuell |
with the engine running and a can of starter fluid spraying around all gasket sealing areas. A shift in RPM's while spraying in those areas would suggest a vacuum leak. | ||
| Zac4mac |
Careful you don't burn any facial hair. Ether is Uber-flammable, like flash powder. H-D recommends a propane tank with a "wand" on a hose. Tiny hole in the end of the wand. same result, rise in rpm. I've also heard of a good mister and water - rpms drop in that case. Z | ||
| Maul |
Thanks guys. I will give it a try. Carefully of course. | ||
| Xtreme6669 |
Low fuel pressure could also cause a lean condition... | ||
| Sir_wadsalot |
WD-40 works fine for vac-leak testing and won't kill you as good. The ecm not being tuned for that specific exhaust will cause a lean condition. That's probably all it is. The stock map on the EBR unit is set for the stock exhaust, (unless I'm mistaken), and you've removed 24lbs of back pressure. Prolly just needs more fuel. | ||
| Stirz007 |
The race ECU probably comes with stock map for sea level. As a result, mine runs rich at altitude. So if you are running lean, sounds like there's some weirdness about. Has the bike been denoided? While you're digging around doing the leak test, maybe check the MAP sensor connections (both wires and hoses) if you can get to it. It's located between the throttle bodies, but underneath them. Check the barometric pressure sensor connections too (back of airbox). Could be ECU is getting bad readings and adjusting fueling accordingly. Or, a reflash for your exhaust may fix it. | ||
| Maul |
Stirz, does EBR stiil do re-flashes of ecu? I heard they would for $25 or so. I could go that route if nothing else turns up. Oh yes bike has been denoided and the plug put in a long time ago. This is my fifth season with the bike and I have had zero issues until now. | ||
| Stirz007 |
Race ECU does not support active solenoid, but if linkages, etc. were still in place, I woulda recommended getting rid of them - moot I guess. Contact EBR about reflash. Not sure what the cost is these days. Maybe run injector cleaner through the system and see if anything happens. BTW, when tech said 'very lean', what were A/F values? | ||
| Maul |
Max air/fuel=17.5. The ratio line on the readout was extremely wavy throughout the range. I don't know why but I am leaning toward an ECM issue. | ||
| Jgarner99 |
17.5:1 fuel/air ratio is on the verge of not running. Do you still have the original ECM? Might be worth plugging it in, just to see if things change. | ||
| Maul |
Jgarner99 I do have the stock ecm and will plug it in and check the ratios again. Thanks for the tip. | ||
| Dntndhd |
Ebr Reflashed My Race Ecm In April For $80.Updated From Stock Exhaust To New Exhaust. | ||
| Stirz007 |
From what I understand from the EBR guys, the ECU's hardly ever go bad, so a ECU swap would be an easy way to confirm/discount ECU fail. I'd recommend checking O2 sensors - they drive ECU air/fuel mapping. With engine warm, what voltages do you read? (diagnostic mode cluster readings, volts). If sensors are working right, you should have something below 0.5 volts. If you get 0.5 or better, the O2 sensors may be telling the ECU everything's fine when it isn't. | ||
| Maul |
Stirz, I checked the O2 voltage this morning. At running temp they both read 0.7 to 0.8 and fluctuated all the way down to 0.0. Much higher than you recommended they should be. | ||
| Jimustanguitar |
Carb cleaner is a little less explosive than starting fluid. It will raise RPM's and clean off the dust  | ||
| Stirz007 |
According to the diagnostic manual, normal output is 0.5 volts. Less than 0.5 indicates lean condition, over 0.5 indicates rich condition. Range is 0.0 to 1.0 volts. O2 sensors have been known to fail, but both at the same time seems unlikely - then again, O2 sensors are a lot cheaper than ECU's. | ||
| Stirz007 |
After further thought, I may be barking up the wrong tree. I run race ECU and race harness and no O2 sensors. They may not be supported by your ECU, so it may not matter what they read in retrospect. Maybe a quick email to EBR would confirm whether or not your ECU supports O2 loop. | ||
| T_man |
Maul; how is it starting in this lean condition? I am watching this carefully as I am having a fueling issue of my own (barely starts, I think its too rich due to observing low operating temps - 70 to 80 degrees Celsius). I moved to an area of lower altitude from higher (theoretically it should have leaned out too). I seem to recall asking EBR about the o2 sensors when I got mine and I think the answer was they aren't used at all (closed loop) but I could be wrong that was a long time ago. Speaking of operating temps, in this lean condition what is yours running at (average)? | ||
| Two_seasons |
Typical operating temps should be 172 degrees F to 212 if you are sitting at lots of lights. | ||
| T_man |
Yep, I am thinking I am rich then at 165 to 185F sitting in lights in 75 degrees F ambient temps. Very strange these fueling issues with Maul's going lean and mine going rich for no apparent reason... I am firing up TunerPro RT to lean mine out (when I figure out how to use it!) ECMspy was pretty simple, just need to find the 'global fuel' adjustment and tweak it down a bit. |
