86 vf500 starting problem

Hi VFR world..

Was hopin maybe someone could help with an issue I had today. Bike is a daily driver 86 vf500. Road it yesterday np... went out today to start put choke on half...started... went inside for a min while it warmed up... cameout turned off choke and the bike dies. Tried to start again nothing.

Wait 10 min... tried to start and nothing.... put choke on and it starts..but no matter what it dies when choke is turned off

open throttle all the way push starter turns over but wont start...can any1 point me in the right direction I havent had this problem b4

 

maybe spark plugs, i remember mine used to do that, because the plugs were years old without starting and when i changed it she started right up. when i take off the choke after its warm idles perfect now

 

Good Morning,
If it runs with choke then dies without, that usually points to fuel delivery. Checkyour plugs too to see if they're wet or dry, black or brown etc.
Good luck-

 

I've seen other posts about similar issues. As stated if it runs with the choke engaged and then dies when you back it off, it's definitely a fuel delivery issue. The VFs have a vacuum activated fuel petcock, meaning that even if you have your fuel line set to "on" or "reserve" it's still not allowing the fuel to flow unless the engine is running.

The fuel switch has two places that are right next to each other that the vacuum line can fit on - make sure you put it on the right one (I put mine on the wrong one last week and made it about 10 miles down I-95 before it started stalling on me - luckily the Courtesy patrol guy had a crescent wrench that I could use to loosen the gas tank).

If that's not it, there's a little rubber diaphragm within the fuel switch that sometimes gets a small hole in it and doesn't actuate the fuel flow. There's a way to bypass this altogether and remove the vacuum actuator from the picture.

Maybe a new fuel filter?? Pump??

 

it's plugged up i think

Hello,

I also have an 86 vf500f with the carbs off to work on them for the same problem(though mine was a bit worse had to choke and use starting fluid to get mine to start) your idle circuit sounds plugged up, my gues is you got some crud out of your gas tank and it stopped up your idle circuit and mabey more as well. I would say remove and clean your carbs (all jets), put an inline fuel filter on, and check your tank for rust or other contaminants that may be getting out.





Will R. Seattle, WA.

 

ok 1st....wanted to say thanx guys..i tried alot of sites for some help..and this one is only one where ppl actually replied....(i take that back on another site sum1 said noob and lol at me)

heres another thing i notcied this morning...tried to start her up...NO CHOKE...and right when it turned over i gave it some gas...and it started....rolled ont he throttle halfway..let it rev at like 4k RPMS for 45 secs.....thought it would be good but the 2nd i let off the throttle...dies

after it starts like above...it wont for about 60 mins..then it will start and i can put throttle on it and rev it...but it will die as soon as i let off throttle...and i dont wanna break or damage sumthin, cuz i thought about holding on the throttle for 5 mins or so..to see if its jus starting really hard.

would you still think this would be a fuel delivery problem with what i jus mentioned above?

Also a friend told me that i may have leaned the mix..and i would need to drain the oil and fuel...and replace with new...does that sound like it could be the issue? It was jus a friend makin a guess

once again..thanx for helpin me out..jus got into bikes and i feel really lost

 

First of all the 86 vf's do not have a fuel pump. They are the only year of the 500 that doesn't have one.

I'd start w/ a basic tune-up & a new fuel filter. If that doesn't solve the problem a good cleaning of the carbs and check all fuel lines for weak spots and vac. leaks.

 

your carbs have a slow speed circut and a high speed ciruit , if the low speed one is plugged it will not idle, and will not start witout choke or lots of throttle. and it will startwith choke or throttle as you describe, then die when you turn off the choke or let off the throttle. I am still beting that your idle jet is plugged in your carbs.



Will R. Seattle, WA.