stalles at stop

[ardo]

Good morning everyone, where do you look to fix if the bike starts fine, runs fine starts without choke, every time I stop for traffic light runs for a second then it dies, any Ideas where to look for fix? I appreciate any suggestion.
it has good battery new fuel pump A/F screw adjusted so no farting.

[Lechy]

Idle set too low, should be around 1100 rpm. Could be blocked up air filters, could be bad plugs. If you set the AF when the bike was still cold you are idling too rich. Could be float heights incorrect, could be plain old crappy gas. Could be the battery earth cable with dirty unsecured connections or the cable itself has become de-natured. Could be valve lash needs re setting.
Could be loads of things or a combination.
[emoji41]

[WintrSol]

Assuming idle rpm is correct, the test for too rich idle mixture is while idling, open the throttle some, then let it drop. If the idle goes below normal then returns, it is too rich; if it drops some then eases down, too lean. A good setting is when it drops most of the way, and eases down the last 100 rpm or less.

[ardo]

Hi all, thank you for your response, I dont think it is the idle, in fact the Idle is high, last time I got stuck running out of gas at 97 miles using full tank of gas, including the reserve, what happens is as it gets hot the idle goes higher, I dont understand why, A/F screw turned counterclockwise to make it run rich, I might have turned little more than I need, but if the A/F screw is turned either way too more than it needed the bike should not run smooth right?, the air filters are new front and back, I commute to work so almost twice a week I feel up the tank, so I dont think it is old gas, I dont know if I have aftermarket pipes I bought the bike used with 7.5K miles on it , replaced the fuel lines because the ones on the bike were crimped, and the fuel pump died on me so I got an aftermarket pump, even when I start in the morning it wont stay running with or without choke, a while ago I cleaned the carbs and was running fine,
so ill start with the A/F screw test, push come to show Ill go back in the carbs and clean the idle jets, I just want the easy way out first
I like the bike now it has 13K miles since start of the summer.
After owning many bikes including all the Gs Suzukis from 450 to 1150E I always had inline four bikes this is my first V twin, I miss my all time best ZRX1100. I regret selling it .

[WintrSol]

Sounds like you have an air leak, making it more lean, the warmer it gets. It could just be the tube(s) that connect the air filter(s) aren't seated properly; on the VS1400 and VS800, it can be a PITA to get them on right. The next likely spot is the intake tube between the carb(s) and intake(s); they can crack with age, but mostly get stiff enough that when a carb is removed for cleaning, it doesn't seat well. Last is failing diaphragms and seals in the carbs.

The A/F screw should make it start to slow, and sound like bubbles in the exhaust (really hard to describe that kind of sound) when turned to far CCW, and it should begin to slow and miss when turned too far CW. Fine the two spots when your first hear this effect, if it happens, and set the screw half way between them, or maybe a bit more CCW than that. It can help to aim the pipes at a solid surface, so the sound bounces back to you.

BTW, which bike are we discussing?

[ardo]

Sounds like you have an air leak, making it more lean, the warmer it gets. It could just be the tube(s) that connect the air filter(s) aren't seated properly; on the VS1400 and VS800, it can be a PITA to get them on right. The next likely spot is the intake tube between the carb(s) and intake(s); they can crack with age, but mostly get stiff enough that when a carb is removed for cleaning, it doesn't seat well. Last is failing diaphragms and seals in the carbs.

The A/F screw should make it start to slow, and sound like bubbles in the exhaust (really hard to describe that kind of sound) when turned to far CCW, and it should begin to slow and miss when turned too far CW. Fine the two spots when your first hear this effect, if it happens, and set the screw half way between them, or maybe a bit more CCW than that. It can help to aim the pipes at a solid surface, so the sound bounces back to you.

BTW, which bike are we discussing?

Hi Thank you for simplifying the A/F screw function, I had to work on it this morning i think I had it very lean turned cw. i turned ccw two and a half turn seems like it idled with out stalling, I wander if this will make difference on the gas mileage, last night before the the adjustment I filled up again at 75 miles I filled 2.554 gallons of gasoline so it is almost like 20,30 miles to the gallon, so i hope htis morning the adjustment will make a difference on the mileage also. Ill keep posting the outcome.

cheers

[WintrSol]

As they say, YMMV, but a better pilot setting could give somewhat better mileage, especially if you spend a lot of miles with the throttle around 1/4 open. With a better pilot mix, the transition from idle to 1/4 throttle will be smoother, and there will be slightly more power in that range, so cruising may need just a bit less throttle. Don't expect miracles, though. BTW, does your bike have two carbs, like the VS800 and VS1400? If so, have you done a good sync? Well-synchronized carbs can improve mileage, too.

[ardo]

As they say, YMMV, but a better pilot setting could give somewhat better mileage, especially if you spend a lot of miles with the throttle around 1/4 open. With a better pilot mix, the transition from idle to 1/4 throttle will be smoother, and there will be slightly more power in that range, so cruising may need just a bit less throttle. Don't expect miracles, though. BTW, does your bike have two carbs, like the VS800 and VS1400? If so, have you done a good sync? Well-synchronized carbs can improve mileage, too.

Hi my bike has two carbs, I just had the mechanic sync the carbs I use to sync my own with inline four, but I thought the mechanic would work this time because I had tires to be put on so wanted all done once.