Bike won't run without choke. Rough Idle

VMAX  Forum

Help Support VMAX Forum:

This site may earn a commission from merchant affiliate links, including eBay, Amazon, and others.
Okay so I took the fuel pump out, took it apart. i did not see any rust, but now when I put the fuel pump on it makes a noise the entire time it is getting power and it stopped pumping fuel. Now the bike wont run at all. How could I have put this back together incorrectly? Does it matter whcih screw goes where as far as the plastic bowl. I am totally screwed now if I cant get this back together. A new one online looks like it costs 150 bucks.
 
Did you pop out one of the little rubber diaphragms? The gasket should be sort of crushed in a pattern that helps line things back up properly. There's a how-to on here somewhere, but I can't link it from my phone anyway.

Sent from my Galaxy Nexus using Tapatalk 4 Beta
 
You won't have to buy a new one. Kyle seems to always have one on hand. If he doesn't, Sean probably will.

Sent from my Galaxy Nexus using Tapatalk 4 Beta
 
I will try and take it out and reassemble tomorrow but if anyone has one I would be glad to pay some money for it and send my old one to keep and recondition. I just want to ride this beast and it doesnt want to cooperate.
 
Ok so I tried reassembling today and putting back together. I can hear the pump working after turning the key on and when cranking. I see fuel moving in the fuel filter but it doesnt look like very much if any is making it to the pump. The bike still wont start. I looked at the how-to but my fuel pump looks somewhat different than the ones in the photos on here. I have attached some photos, maybe someone can give insight on if I put this back together wrong.
 

Attachments

  • IMG_0424.jpg
    IMG_0424.jpg
    86.9 KB · Views: 26
  • IMG_0425.jpg
    IMG_0425.jpg
    60.2 KB · Views: 26
Your pump looks brand new. Ok the only two rubber parts in the assembly are what you hear moving around. If it's sucking fuel into the filter then you have a vacuum leak past there somewhere. Fill the lines with gas, aim the output into a jar or something. And see if that helps.

Sent from my Galaxy Nexus using Tapatalk 4 Beta
 
I looked at the how to on disassembling the fuel pump. My bowl looks a bit different. It only has the one metal piece inside and there is no other hole with a rubber tit. it is just solid plastic. I did take the other screws out of the body to inspect the orange rubber gasket and such. I must be missing something here because it worked fine until I took it off. It seems simple enough but just isnt working for me.

Another thing is that it sounds much louder than it did before.

Should the input/output holes be lined up over the two different sections of the bowl? or should they line up in the same section?

I have been unable to locate a new fuel pump thus far. Called a yamaha shop and they said the part has been discontinued. I am at a loss, Im staring at a very large paper weight.
 
Ok so, I am pretty sure I got it all back together right. I saw the pattern someone was talking about in the gasket and line it up properly. I pumped gas through the pump using a syphon hand pump and tried turning the pump on. No leaks. The pump runs but pushes no gas through the line. So the lines are primed and there is fuel in the pump but no movement.:bang head::bang head::bang head:
 
The back side of that big plastic part should look the same as the front. That's where you find the other rubber nipple thing through the metal piece that matches on the other side. Can you post a pick of the back, too?
 
I GOT IT.. Thanks so much for the help. The rubber nipple that I did not see was aligned improperly. Adjusted it a little, put it back on the bike and Started pumping fuel again. At least it will idle now, but still will only idle with the choke and when you roll slow to a quarter throttle it still bogs down and wants to die. Now I at least know the fuel pump is clean.

What scares me is that I was riding it two days ago (before I took the fuel pump apart) and the bike just stalled twice and stopped working while I was doing about 60 mph, no matter what I did with the throttle or the choke.. Then Had a rough time starting. Could this still be pilot jets/dirty carb or could it be something else?
 
Take a look at your fuel filter. Take off the line leading from fuel pick up out of the tank.
By this time, you should have the line pick line and filter in your hand. Blow air into the pickup line.. Make sure air can pass through easily..
After that, (Since you already removed the pump and checked the operation), check the fuel float fuel levels. They should read 17mm +/- 1MM below center of carb covers.
The biggest thing that made my bike go from a dud to at fast bike (I'm still tuning the A/F screw and air intake to get it perfect), was making sure the carbs were clean, Main jets put back to stock.. Previous owner had 3 Mikuni 118 main in there and one DJ 120 (all mixed up and wrong sizes).. I put Mukuni 152.5 for carbs 1 and 3, and 150 for carbs 2 and 4.
Here's the biggest change... I found that my air box was letting in too much air for the jet size and needles I was using (basically it was running lean). So I Blocked off about 3/4 of an inch of the air intake on each side of the air box, allowed for better mixture, which make the engine really sing.. I too have a 91.. Picked it up last year.. These guys on this forum is no joke.. They can help you out, immensely.
 
Quitting at 60 mph could be a charging issue, unless it felt like it was running out of gas. That seems like it would be a fueling issue to me. There's a thread where somebody's bike would die on the highway, but start again at the side of the road. I'd check ground wires, search "crimp fix", and maybe check the voltage at idle and 2500rpm across the battery. That will tell you if it's not charging. Based on what I've read from you in the last couple days, I'm going with fueling issue, though.
 
Man I been through this a few months ago, I change some many new parts - I mean new fuel pump, battery, rectifier, thicker charging wiring, I came back to the carbs being clogging up. I pull the carbs 3 times but the last time i boiled the metal carbs parts in lemon juice. I put the carbs back together with new gaskets and on the bike it ran much better. Then after that I found the manifold boots had a vacuum leak screws was lose - I used WD40 to check for vacuum leaks on the rubber boots all of them.


I had 2 problems, carbs clogging up, and a rubber boot vacuum leak.
After this motor run find. I did order 2 weeks after that all 8 carb rubber boots for peace of mind and install them.

Then a few weeks after that it stated lose top end again but this time I got some bad gas at gas station drain it out - install new gas motor back up running.

"O" to when i drain my gas tank i took flash lite and look in side there was a little rust in there so for peace of mind order a new gas tank to and install it.

Old tank I'm sure it's ok to use but that's me peace of mind all new yamaha parts.
 
I'm still thinking of another new gas tank for myself. I'd even splurge to have it coated before it came to me so I can be sure I won't have to deal with rust again. I already have two tanks full of flakes that I should clean out and sell to somebody for projects.
 
I didn’t know it at the time, but crap in my tank fouled my filter and left me stranded on the road. $175.00 tow bill.. After I got it home, I found all this crap in my filter and carbs. I just filled up the day before.
DSCN1268small.jpg DSCN1269small.jpg up close.jpg
Please Note: the pictures that you see, are after the 3rd cleaning.. All previous attempts produced way more than what's in the photos.
Looking back at all the stuff I removed, I must have had at least, a 1/2 of a coffee cup full of this crap in my tank.

I decided to try and clean my tank by siphoning out the fuel running it through multiple filters, then back into the tank. What a waste of time and money.. I don’t know how many filters I went through.. Maybe 20 of the ones from AutoZone for $3.49 apiece. After all that filtering, I still had crap in the tank. I decided to get a spare tank from EBay - $27.00. I also ordered the KBS 3 step tank sealer kit from Amazon. I followed the directions and it came out great. I let it cure for a full week to be sure it was ready for fuel. Totally worth the time to do it.

Someone said that it was rust from my tank, but 3 things makes me question that.
1) Going by amount of shit that was in my tank from being stranded, the 91 VMax tank, physically is not made up of that much metal, to produce that much rust without me being able to see right through the tank.

2) Looking at the flakes under a microscope, all the pieces are perfectly flat with sharp broken edges, like a micro-jigsaw puzzle.. It looks like a pulverized coating. Rust looks like micro spore growth.

3) Most important discovery.. Rust, even in powered form, floating in water, is still magnetically attractive. NONE of this stuff had any magnetic properties, what so ever.

Now were finding out that the Ethanol is breaking down plastic and there is a class action suit going on about boat owners having their boats messed up when the ethanol eats through the fiberglass tanks and leaking fuel and clogging up injectors.

MANY, if not all gas station underground tanks were polymer coated to prevent rust - pre ethanol days. So, if the ethanol can break down plastics, what can it do to an underground tank?

I think that amount of crap in my tank came from the pump. I only fill my bike up with a gas can now, so I could look at the fuel before it enters my bike.
Just a word of warning.
Why let someone else’s negligence cause you to pay?
 
I didn’t know it at the time, but crap in my tank fouled my filter and left me stranded on the road. $175.00 tow bill.. After I got it home, I found all this crap in my filter and carbs. I just filled up the day before.
View attachment 38217 View attachment 38218 View attachment 38216
Please Note: the pictures that you see, are after the 3rd cleaning.. All previous attempts produced way more than what's in the photos.
Looking back at all the stuff I removed, I must have had at least, a 1/2 of a coffee cup full of this crap in my tank.

I decided to try and clean my tank by siphoning out the fuel running it through multiple filters, then back into the tank. What a waste of time and money.. I don’t know how many filters I went through.. Maybe 20 of the ones from AutoZone for $3.49 apiece. After all that filtering, I still had crap in the tank. I decided to get a spare tank from EBay - $27.00. I also ordered the KBS 3 step tank sealer kit from Amazon. I followed the directions and it came out great. I let it cure for a full week to be sure it was ready for fuel. Totally worth the time to do it.

Someone said that it was rust from my tank, but 3 things makes me question that.
1) Going by amount of shit that was in my tank from being stranded, the 91 VMax tank, physically is not made up of that much metal, to produce that much rust without me being able to see right through the tank.

2) Looking at the flakes under a microscope, all the pieces are perfectly flat with sharp broken edges, like a micro-jigsaw puzzle.. It looks like a pulverized coating. Rust looks like micro spore growth.

3) Most important discovery.. Rust, even in powered form, floating in water, is still magnetically attractive. NONE of this stuff had any magnetic properties, what so ever.

Now were finding out that the Ethanol is breaking down plastic and there is a class action suit going on about boat owners having their boats messed up when the ethanol eats through the fiberglass tanks and leaking fuel and clogging up injectors.

MANY, if not all gas station underground tanks were polymer coated to prevent rust - pre ethanol days. So, if the ethanol can break down plastics, what can it do to an underground tank?

I think that amount of crap in my tank came from the pump. I only fill my bike up with a gas can now, so I could look at the fuel before it enters my bike.
Just a word of warning.
Why let someone else’s negligence cause you to pay?


Wow good info.... I got some bad gas when, I when was coming back in to town a few weeks ago. The station manager remember and the bike. When I got about 3 miles from the gas station bike started popping. I was about 30 miles from my home. When I got home, and check the gas and filter it was orange like color. I call the gas station manager they give me my money back plus $100.00 to go out to eat with my wife. And the check there gas tanks. They shut down the tank I got the gas from. He said we just got the gas this morning.
 

Attachments

  • vmax dirty gas filter.jpg
    vmax dirty gas filter.jpg
    61.4 KB · Views: 20
  • vmax bad gas.jpg
    vmax bad gas.jpg
    64.5 KB · Views: 21
Wow good info.... I got some bad gas when, I when was coming back in to town a few weeks ago. The station manager remember and the bike. When I got about 3 miles from the gas station bike started popping. I was about 30 miles from my home. When I got home, and check the gas and filter it was orange like color. I call the gas station manager they give me my money back plus $100.00 to go out to eat with my wife. And the check there gas tanks. They shut down the tank I got the gas from. He said we just got the gas this morning.

Sounds like you had the bad luck of filling from a tank that just got a fuel drop! All kinds of shit gets stirred up from those drops and goes into temp suspension....station owners claim the dispenser filters remove it before getting to your tank but that's obviously not true!

If you see a tanker at a gas station don't get fuel there....trouble is, they drop fuel in the middle of the night usually and there's just no way for you to know.

Nice of them to kick in $100 for a little chow tho....very few of them would have done that! :clapping:
 
Sounds like you had the bad luck of filling from a tank that just got a fuel drop! All kinds of shit gets stirred up from those drops and goes into temp suspension....station owners claim the dispenser filters remove it before getting to your tank but that's obviously not true!

If you see a tanker at a gas station don't get fuel there....trouble is, they drop fuel in the middle of the night usually and there's just no way for you to know.

Nice of them to kick in $100 for a little chow tho....very few of them would have done that! :clapping:

The gas station manager was very nice about it. Took pride in his station. He shut the tank down man I no that cost a lot of money. He give me money back for the gas install in the bike plus $100.00 for me and my wife to eat.
 
Wow, that's great.. We need more people giving service like that.. Last week, I went to fill up my gas can and this older man positioned my tank against the pump and proceeded to push down and pull back on the hose to get it to lock in place. As he pulled the filler hose out, I noticed that the plastic seam that makes up the two halves of the tank is now split. I don’t know why this guy did this, knowing that this tank is only made of plastic, not metal. Not to mention that the station sells gas plastic tanks.. I explained to the guy that he just busted my new gas can (Sears Sticker still on it), and instead of admitting anything, he said that it was like that.. Now I know what my tank looked like.. I went into the manager of the BP station and showed him what just happened, and explained that now, when I fill up my bike, fuel will be running all over the place. He said he would offer me a new $30.00 tank for $20.00. Why should I have to pay anything.. For all I know, this guy could be doing this on purpose. I felt my blood pressure going up and getting totally annoyed. So before something serious happened in there, I decided to cut my losses and learn from it. I'll fix my tank with some gas safe silicon. When I have to fill up again, NO one will touch my tank.
 
Wow, that's great.. We need more people giving service like that.. Last week, I went to fill up my gas can and this older man positioned my tank against the pump and proceeded to push down and pull back on the hose to get it to lock in place. As he pulled the filler hose out, I noticed that the plastic seam that makes up the two halves of the tank is now split. I don’t know why this guy did this, knowing that this tank is only made of plastic, not metal. Not to mention that the station sells gas plastic tanks.. I explained to the guy that he just busted my new gas can (Sears Sticker still on it), and instead of admitting anything, he said that it was like that.. Now I know what my tank looked like.. I went into the manager of the BP station and showed him what just happened, and explained that now, when I fill up my bike, fuel will be running all over the place. He said he would offer me a new $30.00 tank for $20.00. Why should I have to pay anything.. For all I know, this guy could be doing this on purpose. I felt my blood pressure going up and getting totally annoyed. So before something serious happened in there, I decided to cut my losses and learn from it. I'll fix my tank with some gas safe silicon. When I have to fill up again, NO one will touch my tank.

Nearly every petrol station in the UK is self-service. It freaks me out a little when somebody else pumps it for me.

Sent from my Nexus 7 using Tapatalk HD
 
Back
Top