Fuel Pump

[James Bluemer]

Can anyone explain to me why I must have a fuel pump on this bike?  Won't the carbs feed by gravity in the prime mode? I can't seem to get fuel to the motor and can't test the pump by the book (Haynes) because I can't get it to start. I have good flow in prime, through the in-line filter, and there seems to be gas in the float bowls because it leaks like crazy when I loosen the drain screws.  However I have no accelerator nozzle spray and the bike won't start unless I give it a spray directly into the carbs at which time it starts immediately but only runs for a moment.  The carbs had the Lucky treatment about 200 mil;es ago and she ran like stink for about 100 miles or so.  Then the Vision lurch started, and gradually got worse, along with harder and harder starting, until the last time I rode it last fall and it refused to start at all.  I switched to my other bike for the rest of the season but now I want to get this recalcitrant little tart up for the summer.  I'm thinking maybe turn the pump output T hose around and see if the thing will run on prime.  Any ideas/help will be greatly appreciated as this is rapidly becoming a question of honor.

[Bruce]

I rode all last season without the fuel pump attached. I am running an '82 tank on an '83 so the fuel pump will not hook up right. The only trouble is the carbs sit higher than the bottom of the tank, so the "reserve" does not work, as I found out the hard way (which would be why they have a fuel pump). Good thing a gas station was close.

I plan to scrounge up an electric fuel pump right away to fix it properly..

But anyway, yes, the bike will run without the fuel pump.

Bruce.

[bikehandle]

Did you por-15 your tank? sounds like crud in your carbs.

[rick_nowak]

ditto. get an inline fuel filter, clean out the tank, blowback the needles and try again. you may have to clean the carbs again.  this is a common vision problem and there are many posts re. this.  the 4 outer bottom corners of the gas tank collect water and rust , the rust flakes away and gets into the fuel, getting into the carbs and causes the problems you have.
the consensus here is that once you por the tank and do the follow up these problems disappear.  welcome to a 20 year old bike!

[Walt_M.]

The accelerator pump does not spray unless the engine is running, vacuum controlled to keep busybodies from flooding the engine when it is parked. How is your charging system? There have been some reports of poor running due to low battery voltage. The starter will crank the engine but the voltage is too low to fire the ignition.

[Lucky]

The accelerator pump does not spray unless the engine is running, vacuum controlled to keep busybodies from flooding the engine when it is parked.

that is only true of the 83's.  82's should squirt anytime you twist the throttle.

to Diag: pull the hose off the front right side of the front carb, that goes to the F/R of the rear carb. twist the throttle, you should get gas out of the hose. if not, suspect the accel. pump diaphram, or the little ball check in there (in the body of the carb, under the diaphram) is gummed up.

if you do get gas out of the hose, the ball check & weight under the nozzles are gummed up, or the nozzles are clogged.

you can remove the accel. pump nozzles by carefully grabbing them with large vice grips and slowly twisting them side to side while pulling them up.  (they are pressed in) underneath you'll find the ballcheck & weight. clean this area out well (if their clogged, the carbs should probably be dipped)

If you suspect the nozzles themselves are clogged you can clean them out by using one strand of picture hanging wire to care fully clean it out.  do not enlarge the hole in the tip, you'll destroy the spray pattern.

when you reinstall the nozzles, tap them in lightly with a hammer. they probably won't be too round anymore, and they need to be to allow the top of the carb to fit over them.  you can easily clean them up (make 'em round) with a little light fileing. if the nozzle happens to actually come out of the base, it can be soldered back in with a small butaine torch.

once it's all back together, carefully inspect & adjust where the fuel sprays. if should spray between the inside of the carb & the throttle plate, without hitting either one (at least, not much) carefully bend to adjust as needed.

--Lucky