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Smoke from exhaust

11555 Views 55 Replies 14 Participants Last post by  thecomputerguy
As of yesterday I put on 250 easy miles and throughout the day my cousin behind me said when I get on the throttle it blows smoke from the exhaust pipe. Smells like un burnt fuel so I'm guessing I'm running rich but why all of a sudden now? 2400miles on the bike. I also noticed its been back firing more and more. I have a cobra slip on exhaust but have had that on since new. Any ideas anyone???
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Do you have a tuner too?
No tuner, got fuel at 2 different places that day. Also talked to a buddy from work and last Thursday it was doing it just not as bad so I ruled out the bad fuel.
Not sure if they checked the valves or not I would have to ask.
As for the smoke color it's black when I get on the throttle but in my garage just revving it, it's more grey. I took a video but I'm not sure how to upload it from my phone on here
Upload to youtube the link there.
That's the million dollar question and that's where the answer lies, and that's why nobody can get it right by trial and error and smelling the exaust and test running it unplugging this or that, because the variables are constantly changing. There are many sensors involved in the fuel processing information procedure in the entire EFI system. The 02 sends the final emissions readings, but you have the throttle position senor, load sensor, ambient air temp sensor, barometric pressure sensor, internal engine temp sensor, altitude sensor , ignition timing sensor, gear sensor, RPM sensor, coolant temp sensor etc. etc. Probably missed some but all these work hand and hand in sending ever changing info to the ECM(Engine Control Module) also know as the ECU, the brain that reads ALL this info and makes multiple changes every second to air fuel mixture.
The only guys that have ever got it perfectly tuned and never had a single problem with ANY aftermarket fuel possessor are the ones that have had their system professionally tested and individually mapped specific to their bike.
No disrespect intended, but I can't understand why anyone would think that they could do the work that was professionally engineered and designed to be done by a computer. I guess they just don't understand what all is involved here and I don't know why the companies selling these products don't tell them.
I did extensive research on the subject and came to the decision I wont do a stage 1 power up grade until I can afford all three mods, pipes, intake and fuel possessor plus have it professionally mapped.
I guess I should have posted this on one or all of the fuel possessor threads.
I guess this goes back to what my Yamaha rep. said about switching out the pulley.
what did he say? (i must've missed that post)
Joe, I can't & won't comment on how things perform on modified units. It's senseless to think any of these people have enough engineering knowledge to post anything.
There is not a week that goes by that I don't fix an ongoing issue with a bike, by getting it converted back to STOCK.
The bike was designed to NOT be chugged along - that's not the customer/bike target. This bike was designed to be ridden aggressively and kept in the higher rpm range, spending a minimum amount of time in first or second. The 13 STD & Tour has the personality it seems these riders would be better suited with. With aggressive styling come aggressive mapping and timing.
Correct, (and this should probably be moved to the tuner thread.) But if most everyone was complaining about surging/flat spots while cruising at certain speeds, and unplugging the O2 sensor made cruising better, then is the tuner actually necessary since disconnecting the O2 sensor will keep it running rich at cruise?
I did just that. Unplugged O2 with Cobra Slip-On and stock box. Runs just fine like that. The only time I ride at 10-15mph is in parking lots and still haven't had a problem like you guys seem to have. Maybe my dyno butt ain't as sensitive.:thumb:
I'm curious and it's not clear to me how you guy with 2 into 2 exhaust are collecting the 2 into 1 for the 02 bung to get a true reading off both cylinders? If not why?
Think that would be a ? for Cobra or V&H.
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