What part of carb is this problem coming from?

hi everyone i am new to here but not new to motorcycles i am a auto mechanic but still sorta a rookie to the carb set up on my 84 VF500. ok well to keep everyone on the same page my 84 was a race bike that someone had. they must of moved on to another bike or something cause it kept in a backyard for probly ten years and didnt move i bought it as a set it came with another vf500 but the other was the 86 and it was running more recently then the 84 so it was susposed to be parrt bike. ok so i did my homework and found out the 84 has a 86's motor in it (it doesnt have fuel pump) the other bike's motor was sezied from a dumb ass leaving spark plug out for 5-6 years and they let it get rained on so motor is a no go. so i started my rebuld of the race one firstt thing i did waas pulled both bikes carbs and took them apart to clean. the 84's carbs looked great on the outside but inside had turned into like sap. ive never seen a carb get so frozen in my life i mean u couldnt even turn the butterfly valves. the 86's carbs were dirty but worth saving and im using them now. i cleaned the carbs all the way around but didnt get rebuild kit cause everythingg was not in that bad of condition. "that may be my main problem" should of got rebuild kit for them insted of tryingg to figure this out. so i got the bike running after it sat over 10 years in the elements it would idle sorta alright and would rev up while in neutral but once i took it for the first test ride i found i couldnt rev up any higher then around 5k while in gear out of gear it revs all the way up but sorta slow not as it really should and i then noticed it was smoking from one of the pipes. i did the simple check if all the cyclinders were firing and found that the number one cylinder wasnt firing the exhaust pipe was cool to the touch while the rest i couldnt touch. so i know that the number 1 cyl is not firing at all i got spark and fuel to it cause i pulled plug and it was wet sorta too wet i think. so my guess is that cylinders carb is flooding it out. and so ifs thats so that would normelly mean the float valve is leaking and letting to much fuel into the bowl. i checked that carb and found nothing blocking anything and it was still clean from me cleaning it another mechanic friend of mine said it could be that they havent been synced yet to the motor their on now. so thats my question.... what do u guys think it is i dont have sync tool but i bench synced them right off the bat so theyre close could it just be j need new float valves would they cause it to run like its only running off the slow jet if they were leaking? thanks again guys i really like the vf's and finding this forum is a great help!! Thanks Again!!


Frank

 

Welcome to VFR World Frank,

First, I recommend that you access a factory service manual (print or PDF) if you haven't done so already.

Next, I'd check the float levels (also make sure that the floats aren't full of fuel). If the floats and float levels are correct, then I'd suspect the float needles and seats (and yes, you may very well need a rebuild kit or, at the very least, a float needle and seat set).

I also recommend that you test the carbs for fuel leaks and float bowl over-fill/flooding problems before and after you install them. Once you've gotten past that, you'll want to sync the carbs as per the service manual.

Meanwhile, I'm sure that other (infinitely more knowledgeable members) will offer more defined advice on your FV 500.

Btw, you might consider editing your post by breaking it into separate paragraphs so as to make it easier for us to read.

Good luck, ride safe, and again welcome to the forums!

 

If needle/seat is leaking, wet fuel will be visible bubbling up through the mainjet outlet under the slide needle after you remove airbox top and air filter. Very, very unlikely the problem is related to synch out of whack. :crushed: