Off-idle stumble

dan filipi · Oct 30, 2012

Throttle cables I find easiest with the carbs pulled over to the left, both taking them off and on.

MtnMan · Oct 30, 2012

dan filipi":30dkipxp said:
Throttle cables I find easiest with the carbs pulled over to the left, both taking them off and on.

Thanks, Dan. I will use brand-new throttle cables. Should I first connect them to the carbs or to the throttle grip?

Armin

slabghost · Oct 30, 2012

Throttle grip first.

Sidewinder · Oct 31, 2012

Beav told you what the problem was back in July.

The slow jets control all the fuel until 1/4 throttle but continue to furnish fuel throughout the entire range. The '81 has the slow jets pressed in so when people "clean" or rebuild the carbs most wont mess with the slow jets. Best they will shoot some carb cleaner through them. I pulled mine on my '81 and they were a mess. Bike always stumbled when wrapping up the throttle.

Having said that ..... it ain't easy and you do risk messing up the jets but if you do it right it can be done. The screw extractor will mess up the entrance to the jet but the orifice is deep inside the jet. I just touched up the top of the jet with a dremel and smoothed it up before pressing them back in. (you can do it by hand pressure just make sure they seat good) Make sure you use a good high grade #2 extractor because they have been in there 31 years and won't want to come out without a fight. I'd soak them with PB blaster and let 'em sit over a couple days squirting them every so often before trying to break them out.

I can almost guarantee you will find one or more air cut off valves and/or accelerator valves mush or with a hole. Those valves are vulcanized so hold them up to a strong flash light and if you see ANY daylight through them can 'em and replace them. Randaak gets $200 smackers for his kit but it has everything you will need to totally rebuild the carbs and the quality of the parts is second to none. If it's worth doing it's worth doing right and you will be rewarded with a fine running bike.

I did a little video a while back playing with a new camera. You can hear my '81 running around town if you like.

https://www.youtube.com/watch?v=31fL_zLtZpQ&feature=plcp

Mine was doing the same as you describe before I bit the bullet and fixed it.

joedrum · Oct 31, 2012

only once on every bike do i fight cables getting them off the rack ...and reroute the cable outside the frame so carb rack can come out the side some to deal with cables in or out of the bike....pass this and the heat sheild piece i take off too the carbs are easy to deal with for me ...i can usealy take the rack in or out in about 15 minutes or so ..quite easy...i would never put the heat sheild back on or have cables that traped by the bike frame