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I just got back from a 1500 mile trip through the Smokeys over to Helen Ga and home. The guys that I ride with told me that when we were riding on the slab that accelerating hard at around 75 and 80 mph my bike would puff out some black smoke for a few seconds. I checked the oil and it is on full. Is this normal, I assume that it is running a little rich. There is black smut on the tail pipe.

Thanks for your help.
Mickey Carney
 

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Situation Normal

CARNEYM said:
I just got back from a 1500 mile trip through the Smokeys over to Helen Ga and home. The guys that I ride with told me that when we were riding on the slab that accelerating hard at around 75 and 80 mph my bike would puff out some black smoke for a few seconds. I checked the oil and it is on full. Is this normal, I assume that it is running a little rich. There is black smut on the tail pipe.

Thanks for your help.
Mickey Carney
Absolutely normal and for the reason you state. Dave Dragon's Dragonfly and Bruce Harris' Ms Whoyah were doing it this weekend. Ask me how I know. ;)
 

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Clarification...

Your bike is not running rich. It is probably running normally.

It does run rich momentarily when you crack the throttle full open. Mine does it too, as do all LTs I've seen ridden briskly.

Some of the site Gurus have stated that the rather significant 'Squirt' of gas keeps the head cooler under high load. Don't know if this is in-fact true or not. But, it can cause a small cloud to form! ;)
 

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I think they all have the black smut on the tailpipe. Mine has done it from day 1. The mileage is very good so it can't be running rich.
 

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What year model is your bike? If it's a 2001 - 2004 and you have the the brown wire on the Motronic cut, this is absolutely expected. Even if that's not the case a little soot when cracking it WFO at speed is pretty much the norm. And yes, black soot on the tailpipe is normal on all of them regardless of year model, Motronic state, or how you ride them. With a Remus it gets all over your lower rear bodywork; a little diluted rubbing alcohol cleans it right off.
 

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I have the same black soot on the exhaust and plenty on the rear wheel rim.

I thought when I bought a shaft drive bike I would no longer have to clean black gunk off my rear rim.
 

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ATFLT said:
......The mileage is very good so it can't be running rich.
It's fuel injected not carburated, a computer decides how much fuel it gets and when, so you can get good mileage and be running rich at times. The LT computer mapping is rich when it is not quite at operating temp or on acceleration and lean at other times.
 

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RoyvL said:
I have the same black soot on the exhaust and plenty on the rear wheel rim.

I thought when I bought a shaft drive bike I would no longer have to clean black gunk off my rear rim.
The black dust on the rim is rear brake pad dust, just like the way the front pads coat the front rim. The only advantage with the shaft drive is that it isn't rear rim dust isn't mixed with spots of chain lube :)
 

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mneblett said:
The black dust on the rim is rear brake pad dust, just like the way the front pads coat the front rim. The only advantage with the shaft drive is that it isn't rear rim dust isn't mixed with spots of chain lube :)
Hmmm.........
The stuff on the rear rim is WAY more than the front and looks just like the stuff on the underside of the exhaust.
Why would the engine have to run that rich - seems excessive.
 
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