having some wierd bike issues

[matt1986vf500f]

about three weeks ago i jumped on the bike after it was sitting for about a week, rode it up towards blood mountain about 15 miles into the ride the bike started to spit and sputter like it was running out of fuel pulled off the road let is sit there for a few mins while check over a few things fired her back up ran fine so off again samething 10 miles down the road, so to make a long story short i got it back home checked the petcock it was clean and working cleaned the tank and checked the carb bowls everything is clean, so now it will surge while trying to maintain cruising speed but if you pin the throttle she pulls through the rpm range like it should, i even pulled the plugs out there normal redish brown color so i am stumped need some help guys

[TOE CUTTER]

Isn't that a vacuum operated pet cock?

[matt1986vf500f]

Isn't that a vacuum operated pet cock?

not anymore i deleted the vacum part out of it

[TOE CUTTER]

Possible venting problem? Just throwing ideas out there.

[matt1986vf500f]

Possible venting problem? Just throwing ideas out there.

keep the ideas coming toe mybe i might get lucky, but no again i cleaned the vent in the gas cap out

[volks6000]

fuel filter clogged ??? bad gas????

[squirrelman]

possible.obstruction.inside.tank.blocking.flow....?

blow.compressed.air.backwards.through.fuel.line.with.filler/cap.open

check.for.free.flow.through.pecock.from.tank.to.bucket.from.1/2tank.to.empty......not.dribbles,but.strong,free.flow.

[matt1986vf500f]

it does it when the tank is full or nearly empty

[squirrelman]

so.now.you're.going.to.check.float.height=7.3mm

float.gauge.made.from.creditcard:sides.rest.on.carbbody.and.cutout.is.float.height

[slowbird]

So the sputtering is gone but it now has surging problems at cruising speeds?

[Pcohen]

you deleted the vaccum from the petcock?

[matt1986vf500f]

So the sputtering is gone but it now has surging problems at cruising speeds?

correct.

[matt1986vf500f]

you deleted the vaccum from the petcock?

yes so it on and off only now less thing can go wrong that way, thats the way i see it any how

[JamieDaugherty]

you deleted the vaccum from the petcock?

Here's my How To on this:

http://www.daughertymotorsports.com/...tankvalve.html

[matt1986vf500f]

so far he is what i have found everything is looking clean nothing out of place? i need to seperate the carbs but the a$$hole guy that worked on it last stripped out a screw in the base part of the air cleaner so i gotta easy out it squirrel man i am havign a hard time reproducing the credit card measuring tape thing give me the measurements for it please

[deepdish]

are floats sticking??slides sticking????uhhhh can u put vacum back maybe it needs that not sure why honda would make it if not needed??????good luck

[squirrelman]

MATT,

cu-ou-.on.gauge=floa-heigh-=7.3mm

it's.clear.u.have.some.rust.in.fuel.tank........

flush.her.so.she's.clean.and.consider.a.coa-ing.sealer.like:"fuel.-ank.sealer".from

http://vfrworld.com/forums/first-sec...ellpla-ing.com


you'll.need.-o.clean.-he.small.fil-ers.above.-he.floa-.needles

[matt1986vf500f]

i have another problem the throttle linkage is missing the spring that lets the butterflys open up all the way, f!@#ing dealerships

[GeorgiaRider]

Yo Matt! I thought you were riding N.Georgia tomorrow!
Slap a spring on that B*tch and get out there!
Seriously, let me know if you need any help from the Georgia Gang.
Hope to see you tomorrow.
Gary

[Pcohen]

haha, i want some of whatever squirlmann's got.. dont hide it divide it!

[JamieDaugherty]

you'll.need.-o.clean.-he.small.fil-ers.above.-he.floa-.needles

The English translation of this is "you need to clean the small filters above the float needles". That's what I've also been suggesting to Matt. Have you checked this out yet Matt. Or are you sure that it's the missing linkage spring that is your problem?

[GreyVF750F]

"so now it will surge while trying to maintain cruising speed"

That's telling me your lean at cruising speed. The links below have some good carburetor information that would help you. I believe at your cruising throttle position your using the pilot circuitry and possibly a little of the slide/needle for the AF ratio. The last link you will have to scroll down the page to the carb section. The 3rd one shows how to find your throttle position and what circuit your using.

Motorcycle Carburetor Theory 101
http://users.rcn.com/kochc/moto/carb/carb.html
Find Motorcycle Engine Carburetor and Jetting Problems - Tech Review - Motorcycle Cruiser
Sabre/Magna FAQ v2

"i even pulled the plugs out there normal redish brown color "

You can not read plugs that way. First off the unleaded fuel used today does not color the porcelain insulator of the plug. The only way that happens is if an additive is added to the fuel by the owner. Or your using race gas with lead in it. Some racing unleaded racing fuels will put an additive in just to color plugs also. You have to read the color change in the shell base, bottom ring of the plug and the ground electrode. New they are shiny. When burning correct the base ring should be dis-colored 3/4's of the way around and the electrode should do the same about 1/3rd from the tip. You can only really read plugs if they are new, then take your vehicle out and do a WOT thru the gears holding it WOT, then quickly shut down with out idling of powering to a stop. Pull pugs then read them.

Hard to tell by the plug photo's because they are fuzzy. But they do look like the total ring and electrode is dis-colored. Shows your very lean. They dis-color with heat. Hope this info helps.

[matt1986vf500f]

The English translation of this is "you need to clean the small filters above the float needles". That's what I've also been suggesting to Matt. Have you checked this out yet Matt. Or are you sure that it's the missing linkage spring that is your problem?

no i think thats might be part of the problem but not the whole problem

[Pcohen]

how new is your fuel filter? check it for bubbles when the engine is running. may have a tiny hole in your fuel line or somehting like that. My bike did the same thing for a while.. it would sputter and start to loose a lot of power like it was running out of fuel and then mysteriously come back to life. it was real embarassing in traffic. i replaced all the fuel lines and the filter and the problem stopped. i would check all the simple stuff like that before tearing your carbs apart

which spring are you missing? i have a few extras laying around

[matt1986vf500f]

how new is your fuel filter? check it for bubbles when the engine is running. may have a tiny hole in your fuel line or somehting like that. My bike did the same thing for a while.. it would sputter and start to loose a lot of power like it was running out of fuel and then mysteriously come back to life. it was real embarassing in traffic. i replaced all the fuel lines and the filter and the problem stopped. i would check all the simple stuff like that before tearing your carbs apart

which spring are you missing? i have a few extras laying around

its the the two sycn springs for the butterflys FILTERs we dont need no stinking filters , i'm not running one

[jporter12]

its the the two sycn springs for the butterflys FILTERs we dont need no stinking filters , i'm not running one

One of the times I had put mine together I was missing one or two of those, and let me tell ya, it WILL run like poopoocaca. Without those springs in there, the associated throttle plates will be free to move A LOT, and not stay where they should be, relative to the "master" carb.

All of the times I had mine back together, I had them so far out of sync that it was basically idling on 1 cylinder. I had done a "bench sync" before putting them one, but that wasn't close enough. I ended up using those springs to my advantage, and adjusting the three "slave" carbs so that they move about the same distance when pushed shut, through the carb inlet (past the slider and needle.) THAT was a HUGE improvement, and actually using the carb sticks to sync them made it just a little better (I was surprised that only one of them was very far off! The other two one took a little adjustment, maybe 1/8 turn!)

I would not mess around with it until you have all 4 throttle plates working together, then get them as close to the same as possible.

[Pcohen]

its the the two sycn springs for the butterflys FILTERs we dont need no stinking filters , i'm not running one

aight i'll check in my shed for those springs and let ya know somehting. your talking about the little ones on the sync screws right?

[slowbird]

I'm happy there is a thread now on the intertubes with the word: "Poo-Poo-caca" in it.

[JamieDaugherty]

its the the two sycn springs for the butterflys FILTERs we dont need no stinking filters , i'm not running one

Just to clarify - the 86's are not supposed to have a filter, they came that way from the factory. They run a gravity feed system and all (that I know of) Honda carburated bikes afterwards ran a similar setup without a filter.

[volks6000]

here matt is from manual