I just picked up a 79 110 from a farmer for a buck and a half. This thing was running pretty good on the street in front of the house until our @$$hole neighbor called "the man" because he wants to sleep durning the day....anyway the kids were riding it in the back yard just using 1st and 2nd in high and now it will run good then sometimes have no power and backfire then a bit later run good...whats up? fouling plugs? the plug is black....any help????

THANKS

 

You say that it will run good for a while run bad and the run good a bit later. Can you go into more detail about it.

Does it take it a long time for it to start runnin bad when its sat for a long time?

What have you done to this atc?

Was it sittin for a while before you bought it?


If it runs good till it warms up then your runnin too rich if it runs bad until it warms up your running to lean.

 

it does not matter if its warm or cold. No mind you it ran good out on the street in front of the house. Problem only started when we ran it in the back yard with limited space.

sometimes it runs bad right off the bat sometimes it takes a while, remember we are not running over 2nd gear in the back yard

we have cleaned the tank, removed, cleaned and re-installed the carb, changed the oil and just basic stuff


I can not tell you how long it sat prior to me getting it. I can tell you it starts pretty easy and also when its running like it missing/starving for fuel it is 9 out of 10 times ok at idle in netural.

Thanks for the reply!!! I am going to get a new plug tomorrow anyway.

 

ALSO... there was a bit of crap in the tank before I cleaned it. Could this have helped foul the plug as well??

 

a clog in the tank would cause a lean condition and the plug would be white/grey
Have you tryed replacing the sparkplug and running it? Use a DR8HS NGK ONLY! and make sure the gap is correct.
Does your bike smoke at all? durring startup? while putting around? while at full throttle?

 

it does smoke a little, not much...

 

So then if it smokes I bet you have oil collecting on your piston and thats why it runs sorry when your just puttin around but when you get it out on the street and let it wind up a little more it clears all the oil out letting it run a little better.

What does the plug smell like oil? Gas?

 

it smells of oil. I figure its not a puttng around kind of bike???

 

UPDATE:

Replaced the plug, problem seems to have gone away. However now I have a new issue, in gear without throttle it takes off....I am sure I have an idle speed wrong, which screw is it to turn it down??

THANKS

 

The problem with the plug will return sortly. If you dont want to mess with rebuilding it keep a few plugs handy. The idle screw is on the side of the carb with the spring on it. You will want to screw it out since it is idleing too high.