Bike doesn't fire up on choke like it used to. Have to give it throttle to start. Then it runs fine. Any ideas?
Quote from: twangin4u on May 02, 2020, 10:15:46 PM
Bike doesn't fire up on choke like it used to. Have to give it throttle to start. Then it runs fine. Any ideas?
Wanted to add that I removed carbs for a cleaning and was having an issue with #3 float needle not seating. Would watch fuel some up and out choke vent when fuel pump ran. Flipped carbs over. Blow in fuel line. Couldn't blow. Flipped back over hooked fual line back on and fuel ran out again. Adjusted float height and it stopped. In other words when I turned the bike on I didn't hear the fual pump running but for a second. Then today the fuel pump ran for a few seconds to build pressure.
The choke isn't really a choke, in the old school meaning. Rather it is an enrichener. There is a very small orifice that is uncovered when the "choke" knobs are pulled open. One or more of these orifices are still plugged.
Look at the brass plunger ends. The steel pull rod fingers will wear through them over time and then it will have nothing to pull on causing the choke to not work at all. Could be on just one or all four carbs.
Twangin4u,
I'm no expert on carbs, but given the crap gasoline we might get these days, I'd suggest using a can of fuel injector/carb cleaner in the tank, mixed according to the directions on the label.
On the topic of gasoline, do you use ethanol gasoline? I only use non-ethanol in my bikes. Find your state, and you can print out the list of your local sources. Not all are gas stations - one near me is a boatyard, and one is a refinery (who knew they had credit card pumps inside the fence?).
https://www.pure-gas.org/ (https://www.pure-gas.org/)
:hi:
.
Quote from: RPM - Robert on May 03, 2020, 03:47:07 PM
Look at the brass plunger ends. The steel pull rod fingers will wear through them over time and then it will have nothing to pull on causing the choke to not work at all. Could be on just one or all four carbs.
I assumed, since he rebuilt the carbs, that he would have noticed this defect. I rebuilt one set of carbs by cutting off the brass tits on the end of the enricheners. I then drilled and tapped the brass rod (it's really small!). I inserted small steel screws which could be used to pull the enricheners open. Voila!
If the carbs were not separated from the rails, that would not be noticed...
Randy - RPM
You can read about the drill and tap of the choke plungers here http://www.fjowners.com/index.php?topic=18143.180 (http://www.fjowners.com/index.php?topic=18143.180)
or you can buy the chokeplungers from RPM
Quote from: Motofun on May 03, 2020, 07:23:55 PM
Quote from: RPM - Robert on May 03, 2020, 03:47:07 PM
Look at the brass plunger ends. The steel pull rod fingers will wear through them over time and then it will have nothing to pull on causing the choke to not work at all. Could be on just one or all four carbs.
I assumed, since he rebuilt the carbs, that he would have noticed this defect. I rebuilt one set of carbs by cutting off the brass tits on the end of the enricheners. I then drilled and tapped the brass rod (it's really small!). I inserted small steel screws which could be used to pull the enricheners open. Voila!
I try not to assume anything. With half the hodge podge, pieced together stuff that we work on that has either been overlooked or "repaired by a mechanic". I find it best to cover all the bases and not assume that everyone knows what they are doing. Just because you and I may know to look at them, doesn't mean John Doe does.
There is that saying, "When you assume; you make an ASS out of U and ME."