My 78 was puffing some white smoke. I went to the guy that built the motor and he told me it might be running rich so I leaned it out a little and white smoke went away now when I give it the throttle it puffs a little black smoke . It is a stock 78 with a bendix carb and short pipes with no baffles and a lollipop. It seems to run great no hesitatation when I go up thru thew gears. The plugs look good. Oh ya I do run 100 octane in it as well. So is everything as it should be or is the back smoke the sign of an issue?

Thanks
T-Ron

 

I think the white smoke is probably moisture (steam) or blue smoke (oil) that looks white in small amounts. Black smoke is fuel (rich) and is probably related to the accelerator pump.

Ideally, you want the air/fuel ratio correct... I would be concerned over running it too lean and would rather be on the rich side, for safetys sake. If you aren't fouling plugs, it probably isn't a big issue.

 

What GA said

 

my 69 sporty would blow 2' flames out the pipes.. never much smoke thou..

 

My 77 XLH is all STOCK like your 78. It had a Bendix Carb also but I change it with one that had a MAIN JET.. No more SMOKE at all. I would ride about 100 miles and check the plug's for color. THE ONLY WAY TO TUNE A BENDIX CARB IS TO HAVE ONE WITH A MAIN JET..

 

yah, i ditched mine and did the cv conversion....its a totally different bike now.

 

I have a Bendix on mine...the old style that isn't adjustable. I have no complaints with it. At times it just makes the ride more interesting...found myself changing the Main on the side of the road on a mountain pass in BC a couple of times....but that just added to the stories I get to tell...

 

So were rejetting for altitude then or what? I have the same carb on mine with the non-adjustable main.

 

Yup, It was starting to run a little thick. I had to drop two jets going up...one at a time...and restore them down the other side and into Vancouver.

Tractor-trailers of lumber going down the mountains added to the excitement of road-side tuning.

s

 

Blackcherry: I glanced at your profile pic after my previous reply and saw your 07 and it didn't match your comment (see quote). I checked your profile. The '75 'ch is a great looking bike that should be displayed as your avatar. It looks like a bike you would enjoy riding and tinkering with for years.
s