Blowing smoke

[desmodromic]

My bike is blowing black smoke when I give the throttle a really good yank. And if I give it an even better yank, I can sometimes induce it to spit fire out of the exhaust.

It has an FP1413 chip, EVO air filter, and Arrow exhaust. I just replaced the spark plugs, cleaned/oiled the air filter, checked that TPS=0, checked that fuel pressure was at 44psi. And still no dice.

Any ideas on where to look next? I started playing around with the idle mixture settings, but initially these don't seem to have a large effect on the problem. All vaccuum hoses appear to be connected as well.

Thanks.

[Exdukenut]

Running way too rich me thinks. Maybe try a hotter plug, and get it gas analysed, would be a good starting point.

[Striptyler]

if you have over oiled the filter, it can restrict the airflow causing a rich condition... If you've gone way overboard, you are actually pulling in oil with the air...check it with the filter off maybe...

[Chabby]

Black smoke is indicitive of an overly rich mixture.
Oil burning gives blue smoke.
Old/blocked, or as already stated, over oiled k&n type filter can cause this.
Were the old plugs sooted up?

[desmodromic]

I agree that the bike is running rich. And also, it was blowing smoke before the maintenance, and running rich then as well, but the plugs only had minor soot.

I appreciate the suggestions, and will try them all. But I have a feeling there is something deeper going on here, a bad sensor, something..

[Striptyler]

A dirty Air temp sensor can cause it, as can a manifold pressure sensor... You can use MAF cleaner to clean the element on the intake air temp sensor if it's got dust/dirt on it. MAP... not sure about. otheriwise, maybe it's just set up badly? If you get it on a dyno and it's dirty, 1PSI change in the fuel pressure equates to roughtly 1 step up/down in jetting... 43 psi might just be perfect


Also, isn't the FP chip the one that is trimable? maybe it needs to be adjusted for your new elevation etc...

[anzacinexile]

My 2 cents is dont worry - mine does that with an FP chip

I was initially worried but a quick phone call to FP brought forward he response - " the chip is a racing chip so if you give it the berries, we dump fuel to give the motor what it needs without recourse to emissions, noise whatever".

Just to be sure, I stuck her on a C02 tester and apart from giving it the aforesaid berries, she was spot on.

Been like that for 30,000 miles so far without issues

[ghostrider71]

My old bike (jonsride) ran a 1413 with Rene Himounts, and Rene Airbox.
It too ran a bit on the rich side - and blew smoke when given the "berries".
I never pulled the plugs or had it properly tuned, but it ran like the proverbial scalded-dog when given a good-old throttle-whacking...so I never bothered to "fix" it!

1413's DO have the adj. trimpots, but it seems that anac's explanation from Jorge wud suggest that this is somewhat normal.

A gas analysis wud tell you much more if you wanted to spring for it....

gr

[desmodromic]

Thanks, this is good information. I had noticed a puff of black smoke occasionally in the past, but not to this degree.

When I initially checked the fuel pressure, it was at 40psi, and to be honest the fuelling seemed pretty good to me. I think I might start leaning the pressure back in that direction and see how that goes.

The few things that sparked of this endeavor:

1) A had a few bad tanks of gas in succession, causing the bike to run poorly
2) Fuel prices have economy on my mind, and I was hoping to increase my average of 35mpg
3) It started to dawn on me that the abrupt on/off throttle response may be due to a misadjusted TPS, and indeed TPS was at '1'

So I thought maybe a little tweaking was in order; maybe I should have left well enough alone.

[ghostrider71]

Dpends on what yr bird you have....but I recall that there was a marked difference in fuel pressure between the "old" models and the "S's" -- or maybe that was a mille??
anyhoo -- might wanna double check that spec against the 1413. Seems reasonable to think that the FP might require a certain pressure to operate properly....or even perhaps CHANGE the line pressure itself??

Depending on your miles - you might want to consider changing the fuel filter too!
If you have fuel economy in mind - remember that the ethanol blended E10 will get you 5-7% less mileage per tank.
I've been using this stuff because it's about .12 cheaper than 89octane here in Iowa...but the lower fuel efficiency is pretty much a wash. haven't noticed any remarkable performance issues though.
I'm going to try switching-back to the non-ethanol 89 variant to see if I can improve both efficiency AND operation.
tmi.

good luck.
gr