Fuel Pump Issue??????

VMAX  Forum

Help Support VMAX Forum:

This site may earn a commission from merchant affiliate links, including eBay, Amazon, and others.

Wingstunts

Member
Joined
Mar 22, 2013
Messages
9
Reaction score
0
Location
Phoenix AZ
Coming home from work the other night on the freeway doing about 75 m.p.h., my VMAX started to sputter in 5th gear like it would do when the low fuel light comes on when having to switch to RES. Confused, :ummm:I still switched the fuel selector to RES hoping that maybe the low fuel level light maybe burned out. I wasn't so fortunate! Keep in mind that I had just topped off the fuel about 25 miles before this happen. Getting off the freeway and riding the rest of the way home I noticed that the problem was somewhat intermittent around 5000 but not all the time. Today, turning on the ignition and waiting for the servo and fuel pump to cycle, it sounds like the fuel pump is cycling with only a few and slow clicks. The bike starts (doesn't seem to be a battery problem) and idles fine. Does it sound like I got some bad fuel or maybe the fuel pump is going out? I will run it a little today and see if it does the same thing. If it does the same thing, I'll drain the fuel and replace the fuel filter. If that doesn't remedy the prob, I'm guessing fuel pump or maybe fouling plug. Any input??? Thanks.
 
You can have a clogged filter. Or one of the little rubber valves in the pump itself, may have become dislodged from where it needs to be in order to maximize fuel pressure.....and thereby keep the bowls full under the higher RPM situations. Do a forum search - the fuel pump and it's potential problems have been well documented before.
 
Thanks jfeagins! I just rode it and gassed it pretty good on and off for a couple miles. Seems to be ok now. Maybe it just had to pass some bad gas!!! BAHHHHH!
 
Update: I didn't do anything to it! I runs like a monkey that dipped his nuts in tabasco sauce again. I will change the fuel filter just because it has never been changed and there might be something in it that my cause it to repeat itself again. Plus, it is nearing 20K. Thanks for all the input.
 
I know this is an old thread but mine is doing the same thing! So instead of starting a new one I figured I'd pull this one back up. I just bought the bike, put a little of 300 miles on it the first week and then started having the issue. 5th gear @65-80mph and it misses and sputters like its out of fuel!! I changed the fuel filter which wasn't to dirty and checked the air filter which was completely clean (K&N)
Any input is appreciated, thanks!
 
The bike is a 99 with 22,500 miles. The guy I bought it from did not have it long but had some paperwork from the previous owner, carbs were rebuilt at 16,000 miles back in 2012. A K&N as I mentioned and a two brothers full exhaust with carbon muffler (which I don't care for) don't know if any jet kit was installed or not.
 
You can also take the ends of the fuel pump and see if there is anything caught up in the fuel pump.

Sent from my SCH-R890 using Tapatalk
 
Keep in mind if the rubber disc in the fuel pump has become dislodged it will usually keep the fuel pump running or running for what seems alot longer than normal.
 
Is there a rebuild kit for the fuel pump or do you just buy another one? Is that a common problem on these?
 
Too lean? have you tried lower speed at higher RPM. Fuel pump or lean, either way equals not enough fuel at higher requirements.

Matt
 
I pulled the fuel pump and gonna pull it apart and see what I can find
 
I looked over that thread, very helpful! If I don't find anything is the next step adjusting the fuel/air mixture? It doesn't do it at lower speed, I got on it in second gear and took it right below redline and no issues at all! It seems to be in 4th and 5th gear only.
 
Last edited:
I pulled apart the fuel pump and everything looks fine, both grommets are in place. Now gotta move onto to something else...... What I didn't want to get into, CARBS! Don't even know where to start with those
 
Have you tried the "shotgun" yet? It could your pilot air jet clogged. Seafoam?
Also how is rhe spark in the plugs? Healthy? How do the plugs look?
 

Latest posts

Back
Top