fuel level and fuel pump

[Black wing]

ok so i set my carbs floats to 16mm below the two lines on the back of the float bowl when i tested them first after taking them off the bike they were in the ball park of 18 - 19 below the lines. but now with the fuel level up i get alot of popping at idle and when i rev up and down i get what sounds like rattling but i suspect is excess fuel igniting. i dont know why its running so rich if thats where its supposed to be, and to make sure i hadent set them too high i took the fuel pump out of the bike as well, set it up to a battery and a switch and am using the fuel pump to fill the bowls which is still giving me 16 below lines.

 

and to make my confusion worse the fuel pump doesn't seem to come on consistently i can flip the switch and get nothing for a couple of switches and if i empty the bowl with it on sometimes it comes on right away and sometimes it dosent come on at all

 

so ive got what seems to be an overly rich condition at idle causing popping and snapping and at the high end on the highway i have no power half the time and lots others. as well as the spark plugs staying super white at the porcelain.

 

am i setting the the fuel too high and just having it lean out on the highway due to a worn pump? and is there an aftermarket fuel pump that's reliable instead of buying yet another used pump?

[jasonm.]

News flash...you set the floats WRONG. That mark on the bowls is NOT what the manual says to use. Reason- the bowl covers can move 1mm . There are raised marks on the carb BODY that you are suppose to measure from. These are ONLY seen from the top/side area of the carbs. These line up dead center of the slide bore.

[frankd]

The fuel pump on Ventures is a demand pump. If the carbs are full and the needles are shutting off the fuel flow to the carbs, the fuel pump will do nothing. When you hear it clicking, it's moving fuel----it's probably just fine because 1st Gen bikes seldom have fuel pump problems.

 

When you are checking the fuel level in the float bowls, do you have the bike level? I measured my bike's level by using a short level on a front and back carb with the air filter removed. Did you re-adjust your idle mixture screws after raising your fuel level? If not, peak up the idle speed by adjusting each mixture screw. They should need to be screwed in some now.

 

Frank d.

[jasonm.]

Don't do anything till you set the floats Properly as I described before. You clearly have too much gas in the bowls. Sounds like you removed the carbs. = good. Did you make sure with a small bubble level...the carb(s) are level when being set ? I am not kidding here. I split my carbs into two sets and put them in a vise w/ (wood blocks). Made sure I checked they were level 4 ways to the moon. If you do not correctly set the floats...you will just get poor mileage and waste time messing with other adjustments not truly fixing it. As for the pump...it's a demand pump with built in pressure sensor. It does have "solenoid contacts" that can wear. But also can be cleaned.

[Black wing]

im not seeing any marks on the sides of the carbs

[jasonm.]

they are cast horizontal lines only visable from ONE side of each carb(s) near the top, just under the diaphragm area.. They are there. And can be seen while the carbs are on the bike using a flash light. If you have a factory manual....it shows. But I suspect you do not. My camera batteries are dead. Hope someone else can post a picture. Also you did not say what got you started on setting the floats...? FYI- floats lose their boyancy over time causing the fuel level to rise. So the level being too low on old floats that NO-ONE else has played with ...is impossible. The level always rises over time. Out here, it's the ethanol fuel that attracts water...which the floats hate water..

[Black wing]

ya the carbs were rebuilt before a bought them everything in them is new

[jasonm.]

read this carefully. look for the Mikuni logo near the diaphragm area of the carb(side)...then just below that is "made in japan. The casting line is between the logo and made in japan. I will try to attach a pic or 2 from my spare set of carbs. So , you reset the floats because ...?

[Black wing]

awesome thanks