700s 1 and 3 carbs are fubar but 2 and 4 are perfect??

Ok so i just got my nice "new" 1987 VFR2 from a friend who cant ride anymore cause hes just goten to old. Anyways. started the bike the idle seemed right. The carbs all seemed in sync, but then the carb on cylnder 1 started spraying fuel out of a nub on the bottom.

The carb on cylinder 3 dripped a small amount of fuel out of the nub on the bottom. but no where near as much as carb 1.

The heck of it is carbs 2 and 4 are completely OK. not a drop of gas from them. Anyone have any idea whats going on?

Also the bike ran for a good 3 minutes or so after i shut the fuel supply off.


Well i put my nice and shiny carbs back in today and she ran like a champ without any fuel leaking!! thanks for all the great advice guys!

 

First off Welcome to the World.
Have you had the carbs off for cleaning yet? Could be any old dirt making the screw up. After you shut the fuel it was running off was left in float bowls.

 

I havent fully opened up the carbs yet i was hoping to avoid the hassle. But just looking through them after pulling the airbox off. they looked pretty clean. Much cleaner then we popped open my brothers 66' carb

I figured the 3 minute run time was just a little excessive and that it only targets the Odd numbered carbs.

My brother thinks the floats in the 2 carbs might be stuck what wisdom can you share with me?

 

It is very common for the bowls to leak if it has been left to sit. At the age of the motorcycle the seals dry oot and shrink up a bit. Often if you run some fresh fuel through the system and let it sit they will seal up. Your other option is to replace the seals. If you remove the carbs be sure to remove them as a complete unit, NEVER......EVER....NEVER......EVER.....NEVER....EVER REMOVE THE MANIFOLD BEFORE PULLING THE CARBS OFF.

 

Now I'm curious...

 

Something I did not know 10 years ago when I Pulled them off '82 my V45 Magna. Was misserible.

 

Well crap. What do you mean by miserable?. I pulled the 2 carbs and popped their bowls off and sure enough they had a ton of crap in them. But is the crap really all it takes to make them leak out of the small hole that is corked by the screw? All the other gaskets held tight with no leaks.

 

The "best way" to work on the Honda V4 Carbs is to remove them and clean and see this (IMO)...

When that intake/ airbox comes off you now get the pleasue of dealing with the linkage and springs between the carbs.

 

paying tuition or school of hard knocks,

either way, an education is expensive...

i would bet that the carbs were not shutting off because the varnish was keeping the inlet needle valve open. The gas was dripping off the lowest point of the vertical carbs after running out the overflow vent located up higher in the carbs--it was not leaking from the drain screw port.

The front carbs are leaking also, but due to the downdraft angle they are draining down into your intake manifold and into the crankcase past the rings--go check your oil/oil level, it is probably fairly contaminated with fuel. i once drained 3 gallons of "oil" from the crankcase of an old vfr with clogged carbs.

Removing the carb plenum plate is not recommended until the carb set is on the bench so you can catch all the synch and throttle end springs and not break the expensive fuel tubes. Plus it is likely impossible to reassemble on the bike.

There is plenty of free info on this site, last time i checked the search function worked pretty well. A factory service manual is a cheap investment too and will save you from going down that "miserable" education route...

 

You've checked that the screws at the bottom of the float bowls are tight ??

The alloy inlet needles are subject to some corrosion, and chrystals of aluminum oxide can build up at the sides and at the needle tip area. Cleaning with a scotchbrite pad is recommended, but don't put much pressure on the rubber tip. Use some scotchbrite to scour into the needle seat area too.

In this case, as TC suggests, i'd suggest that you wait a day or two for the float bowl O-rings to swell up and seal........but you need to crank the engine to refill the bowls with fuel.

The fact that the bike starts and idles is a possible indication that no work needs to be done on the carbs, so don't pull them yet.

Have you checked with a flashlight that the fuel tank is clean and shows no signs of rust ?? Draining the float bowls into a glass jar can reveal signs of rust lurking in the carbs.

 

I am positive that the gas was coming from the port at the bottom of the float bowl. On carb one it was a stream of fuel. on carb 3 it was only a slight slow drip one drop every 17 seconds or so. Carb 1`s leak had pressure behind it. Im guessing that the needle did indeed stick open. So lets find out why. Tomorrow I will have my carb guy take a look at the needle.

Just Cause you made me wonder about the front two carbs tho, I did check the oil. No fuel. It was just as clean as when it came out of the bottle.

I am curious. By now i know i should have pulled all 4 carbs at once instead of just 2 but is that even possible in a bike that hasnt had the carbs gone through in this long? Just pulling the two out felt like they were welded in place.

Also I did check the screws were tight while it was spewing but i was affraid i would strip the carp if i tried to tighten it anymore.

 

Maybe the screw had been overtightened to the point of cracking the thread boss of the drain port--i've seen that before on Mikuni carbs, Since you have the bowls off it would be a simple test--just fill the bowls with water and see if it drips out the port or not...

Loosen (but don't remove) only the bottom screw on the intake boot clamp on the front carbs and you can use a big screwdriver to pry the carbs (one at a time) up 1/4" or so over the flange on the intake ports.

Hopefully if the plastic fuel tees haven't cracked and all the synchronizer springs are found, you will be able to reassemble the carbs on the bench. And go buy some lottery tickets because your good luck karma is running really high...

 

So far the only thing thats been broken (crosses fingers) is 1 fuel bar, few bucks for a new one. one of those impossibly small clips thats like 5 bucks for 30 and possibly my gastanks petcock. i think the gas is seeping out through the valve itself tryin to find a way to test. I am feeling lucky lets try a powerball.

 

The bike sits.
Then the idle jet gets clogged from varnished fuel.
The float needle sticks and then when you try to start it the float bowls overflow and you think the float bowl gasket is leaking. NO, The gas overflows out of the float bowl vent and you think it is coming out of the float bowl gasket. Float bowl gaskets almost NEVER leak.
Many of those float bowl gaskets last the entire life of the motorcycle. Just smear a little Vasoline on them during assembly and they will not get stuck on the aluminum surface of the carb body.

Always REPLACE the float needles do not try to adjust them. Won't work.
Matter of fact if no one has ever messed with the float adjustment and you just replace the float needle you may never need to adjust the float adjustment.

Unless you are one of those people that take the carbs off, remove the float bowls and throw the carbs into a box of parts, and the floats get all beat up and ruined.

I have seen this several times on the internet sites.

 

After seeing the price of carbs on my brothers and friends car i was debating wether my carb belonged on the workbench or in a safe on a pillow. 600 and 800 dollars respectively.

Finished going through the carbs so now i just gota wait for my dealer to get the new fuel line in and ill be set to put them back on the bike

 

Well while i wasnt looking my brother thought it would be a good idea to pull the throttle cable off the bike without remembering its route. Could you guys give me some help on how to get it back in......and some ideas on what object i should use to hit him?

 

First of all why in the hell would he think pulling the throttle cable off the bike would be a good idea.:chairshot: But now that it is off, use it to flog him then choke him with it. My cable runs off the throttle, outside the right fork tube, out in front of the steering stem, inside the left fork tube. Now that it is on the left side of the bike it tucks into the v in the frame and onward to the carbs. Sorry no opportunity for pics.

Next, when Toecutter gives advice, regarding bikes, especially carbs,( not women , mothers or sisters) LISTEN. You need to always take these carbs off as a unit and NEVER remove the manifold. Mine has a similar problem. If it sits for a couple weeks the carbs start to leak again. I just had to spend the last few days starting, letting it run catching the fuel with a towel while it dripped. gaskets finally sealed up and I took it for a ride on Monday, no leaks.

Good luck getting it all back together. While it is apart find his carb cleaning thread and give them all four a good cleaning...your already there.

 

Finished going through the carbs so now i just gota wait for my dealer to get the new fuel line in and ill be set to put them back on the bike[/QUOTE]

Be sure to get the whole assembly back together and put on as a unit of four.:biggrin:

 

His reasoning was "Oh youre throttle doesnt snap back"....no crap sherlock its not attatched to anything. Anyways good idea on the chocking bit.

Well after pulling the carbs for the first time in years. there would be absolutely no way to pull all 4 at once. the gasgets were just to stuck. now that ive broken em lose tho they can easly go back on. Dont see what the big deal is with pulling the linkages apart. its just a throttle and a choke linkage not too hard.

It might be because I have some experiance with this kind of thing tho. I do gota say Toecutters posts are awsome and full of info!