So confused, 1996 VFR wont draw in enough fuel into engine

I can actually blow through the hose that goes into the secondary air filter and the four slides will move full travel. I believe that tube goes to the vacuum sliders. So I'm really confused as to what is going on with this bike.



HRCH

 

I have been a shop mechanic and have gotten bikes that everyone and all their friends had already worked on the motorcycle and they could not fix it.

This is what a shop would do.

We would assume nothing.
We would start with a compression check.

if the battery is not good we would replace it because you cannot diagnose electrical malfunctions with a weak battery.

The order is like this:
Mileage?

Compression check.
Valve clearance check.
Making sure the timing marks are where they are supposed to be.
Carbs are last.
Assume nothing .
Check every single part.
I would NOT assume the idle jets are ok You even said yourself you cleaned them with a wire. What size wire??? Even a .020 wire would not work on idle jets.

BTW carb diaphrams just need to be checked for holes or tears.
If they are torn it will never idle correctly.

Sometimes the owner of the motorcycle leaves out part of the story.
EXAMPLE: "my brother put the floats in, and ordered them."

In fours years at a dealership there was never a bike we did not repair.
Also one customer brought in a bike for a tune up, and I found out one of the cams was in upside down when the timing marks would not line up. Luckily the valves did not get bent. When he came in to pick up the bike and it was fixed, he finally told us that he had taken one of the cams out when he could not get it tuned up.
The bike only had about 1,500 miles on it.

 

Why do you keep messing with the vacuum slides? They almost NEVER NEVER cause any problems. Makes no sense at all.

Statement from POST #1

"where ever I could get a wire through a port or a cleaner down a port I cleaned it with carnb cleaner amd compressed air."

This is solid proof to me that you did not look through the idle jet and hold it up to daylight. Carb cleaner and compressed air may not clean a idle jet that has set around for FIVE YEARS and is clogged solid.

 

One MORE THING.

Since you said it would not rev up. You can do a vacuum check to find out if the exhausts are clogged up. Ot just remove the mufflers.
If no air can go out then no air can come into the engine and suck the fuel.

It sat for 5 years and maybe the muffler could have got something inside of it.
At least a visual check for a screen inside the muffler.

 

Also you said "So, I'm thinking about getting a jet kit for it."

This makes no sense either. If the engine will not work in its stock configuration why would bigger main jets help?
It would just create MORE tuning problems to solve.

You just need to be more logical about how you do things.

You are in too much of a hurry for a quick easy fix.

BTW....Main jets almost never get clogged. They are just too large.

You need to go back and take those idle jets out. You need a definitive absolute answer. ARE THEY CLOGGED.
Do not try to stick a wire in them, it could ruin them because they are soft brass.
Hold them up to the light and make sure you can see daylight through the hole. Make sure!

If you cannot, you will have to get a miniature drill bit THE CORRECT SIZE or one size smaller and twist it with your FINGERS to get that gooey junk out of there.

Please report back what you find out about those idle jets.

Meanwhile do NOT start removing coils or any other part.

Please be logical.

 

If you use compressed air on the slides you could end up ruining the rubber diaphrams.

 

Think about this:

The bike was running.
It was turned off and sat for 5 YEARS.
The only thing that can happen is corrosion and/or the gasoline turning to varnish.
Or a mouse gets in somewhere and builds a nest.

 

Wow, what a post. Thank you. I must admit that is a lot of help. Unfortunately, I already removed all the idle jets and ran the second thinnest guitar string into the idle jets. I then used compressed air and carb cleaner through all the jets. They were indeed very clogged. I then double checked that I could see light through it and I did. The main jets were also very clogged. I also used a guitar string and carb cleaner, and compressed air.

I'm in a holding pattern now. I'm waiting for one valve shim. (2 sizes down). I'm going to take another look at the carbs. I plan on taking the carbs to the honda dealer for the ultrasound cleaner. I was told it works great. The dealer told me to remove all the jets and diaphram.

Im going to remove the slip on and check for anything that may have ran into the exhaust system. That does make a lot of sense. I do have a timing light so I will also check the ignition timing once I put everything back together again.

Hopefully I will get this bike working correctly. I guess I got lucky when my ZX11 sat for 4 years. All the jets were very clogged. But I did get it running very good.

HRCH

 

if you have4 access to another set of carbs that you know are working slap them on and giver her a go....

 

Yes, the bike did sit for 5 years. There was a few mice nest in the bike. I inspected for damage wiring. I only found a couple damage wires, not too bad. Its hard to get in contact with my brother in law or I would get more answers from him. He did state that the bike was running fine when he last used it.


HRCH

 

I always removed the rubber diaphram prior to blowing compressed air through the carb. I read about that some time ago when I was cleaning out the carburetor on my 98 ZX11. That bike sat for 4 years. The carbs were also clogged really bad. It runs great now.



HRCH

 

The B string on the electric guitar is probably a .013 it would be too large.
The E string is either a .009 or a .010
A #38 jet is.. I tried a .016 drill and it will not go through. It would have to be a ... hold on.

 

OK...A number 10 electric guitar string .010 will go through the #38 pilot jet.
A #11 string will too probably but the B string .013 will not go through.

Good way to do it !!! excellent suggestion.

So that means that second string on that guitar was a set of 9's.
Change those strings to a set of 10's when you get time and you will get a lot better tone and no truss rod adjustment will be needed either.
Most blues and rock players immediately change to 10's as soon as they buy the guitar.

Unless you are Stevie Ray Vaughn, and can play with 13's tuned down 1/2 step.

 

I like 9s of my electrics, however I do have 10s on my less paul. I tried 9s on it but it threw off the neck.

I took your advise and ordered 4 low speed jets. I also dropped off the carbs to the Honda dealer for a ultrasonic cleaning.

Thank you

 

they usually are.. this is just a question not insulting your abilities... you put the carbs back together with the same parts that came off of each one? no mixing of parts from carb 1 an4 3 and 4 kinda thing? I 'm not sure what problems this would cause but I have been told never to mix them....

 

Sounds like you are on the right track.
BTW Do you know what the 12 bar blues is?

 

I never take insult to criticism, it helps me take a look back and see if I could have done things better. As far as mixing parts from one carb to another, I prevent that by only doing one carb at a time. However, I do remove all the diaphrams sliders to prevent ruining them when I blow the carbs with compressed air. I keep the diaphrams in a clear plastic bag. I number each bag. I currently have the carbs apart as I took the carbs over to the honda dealer for a ultrasonic cleaning. I placed all the parts in a separate clear bag and have them numbered.


HRCH

 

I'm not a blues player, I'm more into country and 80s rock.

As far as the bike goes, I'm running out of options. If the carb cleaning thing and new pilot/slow jets doesn't do the trick, my last check will be timing check. I already checked the exhaust pipe as far as I can see it looks clear inside. The exhaust pressure coming out of the pipe at idle felt just as strong as any other bikes that I have.

I actually got a hold of my brother in law yesterday. He positively said that his bike ran fine just before the engine was turned off for 5 years. He did confirm that he had trouble with the battery. He said the battery kept on going dead. I put a new voltage regulator on it and that solved the charging issue. He said he never had any other trouble with his bike. I believe him because I often rode with him. He also told me that he never had the valves done. Not bad, at 30k miles I only measured one valve that was out of specs. Most valves were dead on specs. And the one valve that was out of specs was only out by .05mm.

HRCH

 

One more odd thing I noticed. When I took the carbs apart so I could get the ultrasonic cleaning done, I blew through the float bowl vent holes inside the carburetor. There seems to be two of them in each float bowl. I believe one of the vent holes in two or more of the carb's float bowls seem like it did not blow through anywhere. The air just blew back to the air nozzle of my blow gun. Odd I thought. I didn't spend too much time with it because I had to drop off the carbs at the dealer before I went to work.

So after thinking, I wonder if that is a reason why very little fuel is getting into the engine. In order for fuel to flow in or out of the carburetor float bowls, there has to be a clear passage for outside air to vent in or out

The service guy at Honda said the ultrasonic cleaning will get into those vent passages inside the carb. I'm keeping my fingers and toes crossed.

HRCH

 

Quick update. I picked up the carburetor from the honda dealer today. The manager told me that the carburetor I dropped of the the ultrasonic cleaning service definetly had one or more clog passages. He said he knew this simply because the carb will smoke in areas where there is a clogg. If so, I think it was the carb float bowl vents. When I got home I blew air through the carb float bowl vents and I noticed I could feel air coming out of other ports on the carb. So, that is a good sign and I hope it's just not me having wishful thinking. I should have everything back together on Saturday. I'm waiting for the new idle jets to come in.

HRCH