Hey guys,
I have a 1999 Suzuki Quadrunner 500. It has been idling all over the place, dying after full throttle, being hard to shift especially from 1st to 2nd, and backfiring. We recently pulled out the carb rebuilt and cleaned it, gave it a new oil change, new air filter, cleaned out the gas tank and changed the spark plug. After we rebuilt the carb it didn't want to start, so we tipped it back and fuel poured out everywhere, must have been air in the lines? After that it started and ran perfectly, and it shifted great. Then all of a sudden it started backfiring and acting like it was running out of gas. We pulled out the spark plug (we just put it in and maybe ran it for like 5 minutes) and it was completely black, and smelled of fuel. How do I fix it getting too much fuel and running rich? Or is that even my problem?
I do not know much about atvs so I am kind of learning as I go.
If anyone could help me with this asap that would be great!
Thank you,
Mal

 

Not sure if the old 500 had a lift pump for fuel delivery or a tap. If a tap, don't run it on prime, it should be put on prime to fill the carb after you have emptied it, then set on run for normal use. You also have a leaky float needle, this can be because of a worn needle, or because bits of grit have jammed it open. Cleaning out the tank disturbs sediment. Take the needle out, check for wear etc, you could try it again, or fit a new needle "just in case". If fuel has "got everywhere" it may have got into the crankcase, check the oil level hasn't risen and, if it has, change the oil.

 

I have built a suzuki quadrunner out of a scrap heap..and have had to address a larger pile of issues during the build.but I did address and fix all issues..your carb is running rich you say..OK if the four wheeler has sat up for any length of time the carb gets gummed up and the float starts to stick either open or closed.. Causing the engine to run rich and smoke black or you may notice a rich gas smell while its running..the carb needs to be removed and took apart and cleaned properly.. Soaking it in mineral spirits will do a good job for that and won't harm seals or gaskets..try a two or three day soak in a old paint can with lid half filled with mineral spirits. Make sure the fuel bowl is removed and in the can to soak..use a tooth brush and a guitar string to clean the various ports and areas you can till clean..reassemble and reinstall try to start and see what happens..