Black smoke

[Jonger]

Yesterday I rode my m50 for a few hours and then my bike sat for about 2 hours. At the 2 hour mark I started it up and drove off. About 10 seconds later I floored it and my cousin who was riding his bike behind me said some decent black smoke came out. I basically floored it and rode the gear out.

Is this somewhat normal? I have never witnessed black smoke myself from the bike. It never does this even when started and throttled good.

[outlaw]

mine does it on cold start. after is warms up it doesn't smoke.

[Jonger]

Why does it smoke? Is that unburned fuel? Thats what I assumed it was. It better not be buring oil.

[soundcolor99]

not oil. just suzuki trying to ruin everyones fun, and keep the mixture good and rich... sucks dont it.

[bluem50]

I hadn't noticed any black smoke last year when i got the bike other than when I initially started the bike. This year I've noticed more and the bike seemed to be running a little rough at low rpm's. I've been running premium fuel since i got the bike and so when I filled the bike up yesterday after a 200 mile run I put 87 octane and ran it for about 10 miles -- no more black smoke. Is it possible the higher octane made it run too rich? Please forgive if this is a stupid question!
Also, I have no performance enhancements on the bike, would a power commander help to smooth out the bike or would I just be wasting my money if I am not going to ad pipes or K & N filter etc.?

[Rhodester]

I"m sure that these bikes have a "choke" circuit mapped into the fuel injection system to richen things up when the engine is cold. I would consider a start up after 2 hours a cold engine scenario.

I think that running premium fuel in an engine designed for 87 octane gas is asking for trouble. You'll start to see a gray deposit build up in the combustion chamber. It doesn't, however, make the bike run rich. A Power Commander might offer a slight enhancement for the completely stock bike, but I'd probably save my money unless I was going to go with pipes and an intake. Then I'd consider it (or a similar product) mandatory.

[outlaw]

ok i know this may make me sound like a total idiot, but i was told to run premium in my M. should i be running 87 and what is the reason? i hope i'm not the only person not knowing this.....

[SNAFU]

In my Manual it says 91 or higher. But for (Canada) a minimum pump octane rating of 87 (R+M)/2 method. ???

I did a search and this is what I found in another forum.

It's been a long time since I looked at this but it goes something like this.

Next time you're filling up look at the little yellow sticker that says what octane gas you are getting. It should say R+M/2 method. The R+M/2 method was required by law for fuel companies to grade their product. Some of you may remember octane ratings in excess of 100 not so many years ago and this is why we get R+M/2. The R component is found by taking pure gasoline with no impurities and running it in an unloaded engine until the knock RPM is found (the RPM where th engine knocks on pure gasoline) this gives the baseline. Now run the fuel in question until it knocks. Cut the pure gasoline with (this is part of what I can't remember) a chemical whose name will be ommitted until it knocks at the same RPM as the gas in question. Using how much of that chemical you add and some fancy math gives you the R value. Now go thru the whole procedure again but this time put the engine under a government mandated amount of load and fimd the M value. Divide the sum by two and you get your standardized octane rating.

[Rhodester]

The sticker on the right frame down tube just in front of the front exhaust pipe reads "87 pump min". IMO, I'd stay at 87 or slightly higher, but going too much over that will cause that deposit build up I mentioned above. Most premium fuels that I've heard of are 91-94 octane. That's overkill in my book. For me, I'll keep it between 87 and 89 octane. So far I've only put in 87.

[hammersfan]

My dealer told me to use mid grade and the occasional tank of regular (87)

[Mavman]

Here's a decent thread among many on this forum concerning octane.

http://www.motorcycle-journal.com/fo...ghlight=octane




BTW......I use 89 city 87 highway, no problems here-(knock's on wood).