Had to push it home again..

[Old V65 Rider]

I have been fighting this for a while. Every now and then my bike has been bogging down and dieing, usually after getting on the throttle hard. I finally noticed that when it happens the fuel pump is somehow loosing prime. When I turn the key on it pumps but will not pressure up. Took the gas cap off to let the tank vent better, did not help. I took the vent line off where it connects to the tank and found a restrictor on the inlet tube on the fuel tank. I cleaned out the hole with a torch tip cleaner to make sure it wasn't plugged. I noticed that if I blow on the vent hose fast enough the roll over valve stops the air flow. I took the vent line loose above the roll over valve and took it for a test ride. After hard throttle several short times it lost prime again. To get it to prime back up I blow on the vent line and turn the key on. Fuel pump is new, replaced it last week. Fuel lines are fine. Fuel filter is new. I have taken the fuel line off where it connects to the fuel tank, put another line on the outlet tube and blown on it to make sure there was no restriction there. It was fine. What is the deal!!?? I have had to push this bike home several times because of this problem. At least now I know why the bike is dieing and how to get it going again but I would like to figure out why it is happening. Any ideas?

 

[Traumahawk]

Inside of the stock pump there are 2 rubber diaphragms that will allow the pump to hold pressure, if those diaphragms "fall" out of place, the pump will run constantly.

Is yours a stock pump...or aftermarket?

 

[Old V65 Rider]

It is a new stock pump, one week old. It will pressure up and stop fine usually. Same thing was happening with the old pump.

 

[Traumahawk]

Look at these threads.....it can happen to new pumps as well.

http://vmaxforum.net/showthread.php?t=13823&highlight=fuel+pump+diaphragm

http://vmaxforum.net/showthread.php?t=8707&highlight=fuel+pump+diaphragm

Although it is possible that you have a hole BEFORE the pump, so it sucks air...

http://vmaxforum.net/showthread.php?t=8775

 

[alorio1]

Look at these threads.....it can happen to new pumps as well.

http://vmaxforum.net/showthread.php?t=13823&highlight=fuel+pump+diaphragm

http://vmaxforum.net/showthread.php?t=8707&highlight=fuel+pump+diaphragm

Although it is possible that you have a hole BEFORE the pump, so it sucks air...

http://vmaxforum.net/showthread.php?t=8775

#1 to all of the above by Traumahawk. I just wanted to add check the fuel filter for cracks or leakage and also lines leading to suction of fuel pump. Even the slightest leak on suction side will cause fuel pump to get air bound and loose prime. Check over the lines and filter on suction side of fuel pump again. I would replace fuel filter with a cheap universal fit from your auto parts store, it is usually clear and you will be able to see fuel/no fuel in the filter should the pump loose prime.

 

[Old V65 Rider]

I checked the fuel lines and filter for cracks already. Will try putting tighter hose clamps on my fuel lines on the suction side. If that doesn't do it I will take the pump apart. I am guessing it is probably not the pump since it was happening on the old pump as well as the new one.

 

[jfeagins]

It only takes minutes to remove and inspect a pump. Do it. That way you will know for sure. ALL your symptoms point towards a misplaced rubber diaphram, or two, in the pump IMO.

 

[Old V65 Rider]

Still fighting this. I checked the diaphragms on the pump, they were fine. I also replaced the fuel lines and tightened up the hose clamps since I first posted. I am leaving the roll over valve unhooked to eliminate the possibility of that causing the problem. The only thing that hasn't been replaced is the fuel tank. What else could be causing this problem? Getting frustrating. I want to ride this bike more but it keeps dieing on me.

 

[Fire-medic]

Apart from something like a plugged fuel tank vent line, I am not sure what could be causing the pump to lose its prime.

Let's see, losing its prime means an interruption of fuel flow, yes? What can cause that? As described, a fissure in a fuel filter allowing air to enter, cracked fuel supply line, fuel pump problem, or an obstruction in the flow to the pump.

I don't think it's likely, but have you ever drained the fuel tank and used a flashlight, a borescope, a video inspection tool (HFT sells one for ~$100) w/a flex shaft, or just patience w/your peepers scouring every nook & cranny of the tank?

Drain your tank and take a careful look to see if there is some weighted debris or object which migrates to the area of the fuel pick-up in the tank, temporarily blocking the flow until it moves-away from the pick-up. Maybe a piece of a rubber gasket, a piece of rust/scale, or even a foreign object (though the locking gas cap minimizes that). It's a used bike, right? Take nothing for granted, empty that tank and make a careful inspection. Have you used a wire to clear-out the fuel tank feed?

Years ago, my brother replaced the wax ring to the waste pipe for a toilet. he also replaced the tank rubber 'donut' between the tank and the bowl. Afterwards, he had problems with the water not completely evacuating the bowl. He kept a pail by the toilet, and if you had 'solids' you used the water bucket besides flushing. When I went to visit, and he told me about the toilet, I asked him if he had removed the toilet since it happened, he said, "no." I went w/him to the hardware store for a wax ring, and we pulled the toilet. When I inverted the tank/toilet to empty residual water, a large plastic fender washer fell-out of the bowl water entry port. It was one of the washers which held the tank to the bowl, the washer which was inside the tank, w/a nut, one on either side. It had been acting like a flapper valve, restricting flow into the bowl when it was perpendicular to the water flow, and other times allowing full water flow from the tank into the bowl, when the edge of the washer went inline w/the water flow. My sister-in-law was very grateful!

So, rule out something blocking flow inside the tank.

 

[dannymax]

So, rule out something blocking flow inside the tank.

+1 There is a bottom drain on the tank, might be a good idea to open it up and flush some gasoline thru, see what comes out.

 

[johnpclynch]

Could be your fuel reserve circuit

When your bike dies, try switching to Reserve to see if the fuel pump will kick back in (even if your tank is full and the reserve light is off) you could have a problem in the fuel sender circuit - i.e. your fuel pump relay isn't getting a signal and therefore is not sending power to the pump, switching to reserve (or using the start/stop switch) will force it to pump for a few seconds

http://vmaxforum.net/showthread.php?t=31569

 

[Old V65 Rider]

I will try that video inspection tool. Have a friend I can borrow one from. When I first started working on this bike one of the first things I checked from was rust in the tank. Saw some light surface rust but not much. Rode the bike for about 10 miles this morning without problems but I am expecting it to happen again. Thanks for all the suggestions!

 

[Old V65 Rider]

Could be your fuel reserve circuit

When your bike dies, try switching to Reserve to see if the fuel pump will kick back in (even if your tank is full and the reserve light is off) you could have a problem in the fuel sender circuit - i.e. your fuel pump relay isn't getting a signal and therefore is not sending power to the pump, switching to reserve (or using the start/stop switch) will force it to pump for a few seconds

http://vmaxforum.net/showthread.php?t=31569

The pump is running but not pulling fuel from the tank. I actually do have problem with my fuel sender circuit. The fuel pump will only come on when I have it on reserve. I haven't got around to fixing it yet because I have been working on finding the cause on this other problem. Maybe it isn't coming on while I am riding it sometimes and that is my whole problem. Could be. I will fix that to, can't hurt.

 

[davidon]

Agree w JPC. Check entire fuel/starter cut off circuit for bad relays. I think i had a similar problem and had to replace the sidestand relay which would only intermitantly fail but if your bike is an 85 electrical stuff is pretty old.

 

[D-Max2012]

Don't know if this is relevant. but I Hope it helps.
I had an episode that left me stranded on the road. Only 1 mile from my home cost me $175.00 in tow fees.
Went to fill up the bike then took her home. Next day, I decided to take a spin and that was it..Died on the side of the road..
At the time, I didn't know what happened, and had to get a tow. When I finally got the bike home and examined everything closely, I discovered a Brownish, Flaky substance (looked like extremely large coffee grounds), that completely clogged my fuel filter. Cleaning out the fuel filter was not a problem because it was one of those clear glass filters with chromed end nozzles. Anyway - Started he up again and this Shit blocked up the filter again within 2 minutes. Time to examine the tank.

I siphoned out the fuel into a 5 gallon bucket and HOLY SHIT!!!
All in all, must have had about a 1/2 GALLON of this reddish brown crap inside my tank. Some pieces were freaking large, about the size of 1/2 of a dime.
My friends were trying to convince me that my take was rusted out. I had to explain to them, that it was not physically possible to have that much rust coming from a 4 gallon tank and its still holding fuel. Not to mention, I placed some of that crap under a microscope and fount it to be flat with broken edges, like jigsaw puzzle pieces. Rust looks like a little plant growth under a microscope. Also very important - NONE of these particles were magnetically attractive,,, rust is.

When I went to fill her up, I did not pay attention that the Fuel Tanker was sitting in the station. My mistake.. BIG MISTAKE.

I remembered back in the day on HOW"S IT MADE (Discovery Channel), they showed how gas station pumps and underground tanks are made. They also mentioned that all underground tanks where coated with a polymer to help prevent rust. That's all fine and good, until they recently mandated Ethanol into our fuel. Found out further, that there is a class action suit against the big oil companies, because this Ethanol is destroying plastic parts, Fiberglass boat fuel tanks and rubber fittings. ( smaller engines like lawn mover and weed wackers are suffering big time). Putting one and one together, it looks like the Ethanol broke down the plastic liners inside the underground tanks. When the tanker was there, it stirred up the mix that made it to my tank.
I finally decided to coat my tank with that KBS Cycle tank Sealer Kit.. Also, when I go to the pump, I fill up a 5 gallon fuel tank I got from Sears before adding it to my bike.. That way, I can see whats going in there. I plan to come up with a portable filler / filter that I could carry with me.. Now, my fuel looks like clear water - inside the carbs also.

Sorry for being long winded, but dealing with that tank (what a PITA to remove), That crap, and all the frustration, really made me vigilant on keeping my fuel / system clean.

 

[The Beekeeper]

I'm surprised that the fuel filter on the station pump didn't catch the large particles.................Tom.

 

[D-Max2012]

Nope, It let me have the full flow of crap into my tank.. Then again, this was one of those cheaper gas stations.. I no longer go there.

 

[johnpclynch]

Nope, It let me have the full flow of crap into my tank.. Then again, this was one of those cheaper gas stations.. I no longer go there.

That reminded me of when I first changed my filter with no sign of any rust in my tank

http://vmaxforum.net/showthread.php?t=9512

 

[sdt354]

I'm surprised that the fuel filter on the station pump didn't catch the large particles.................Tom.

I may be superstitious Tom, but if I see a tanker truck at a gas station, I've always keep rolling. Nothing ruins a nice day of riding like the above mentioned.

 

[Redbone]

I may be superstitious Tom, but if I see a tanker truck at a gas station, I've always keep rolling. Nothing ruins a nice day of riding like the above mentioned.

That is a good policy, ask any of the fuel delivery guys and they will tell you the same thing.