M620 Fuel Pump Issues

Vishwacorp · August 19, 2011, 08:29:19 PM

Hello all,

The motorcycle was parked on the street today uncovered when a huge rainstorm came and passed. I went outside and turned on the motorcycle while I put on my gear and it fired right up. 6 seconds or so in, it died. So I tried to fire it up again with no success. And again. I tried with the engine choked and without. All the lights and the horn work and the starter motor sounds just as strong as ever.

I can hear the engine cranking when the starter motor is trying to start it but no firing. The bike did respond a little sluggish at times earlier in the day so I'm thinking maybe it's the spark plugs? Additionally, when I opened the fuel filler cap to check how much gas I had in the tank, I noticed a good amount of water around the "hole" for the gas tank. Maybe the seal has gone bad and leaked water in the gas?

Because of the neighborhood the bike is in, and also because I don't have the facilities to tow it anywhere, I'm going to try to change the spark plugs tomorrow and see if that fixes the issue. If not, then maybe drain the tank of fuel and add a new gallon of gas and then give it shot before giving up and taking it to a nearby mechanic. Changing the spark plugs is a simple job but I would appreciate advice on how to drain the gas tank and if there's any other culprits I should be looking for that might prevent the bike from starting up.

Thank you,

Ankur

Vishwacorp · August 20, 2011, 12:03:22 PM

Apparently the thing to do in this case is leave the bike to dry overnight and then come back to it in the morning, when it'll start up right away without a problem. Then you get to ride it home and pay the ticket NYC traffic cops left you as a little present.

Howie · August 22, 2011, 05:00:23 AM

Chances are you have secondary leakage from the ignition coils or spark plug wires. An easy shade tree check is start the bike up at night or in the dark and spray water on the coils and wires with a spray bottle and look for sparks.

Vishwacorp · August 22, 2011, 12:09:04 PM

Thanks Howie, I'll give that a shot.

Vishwacorp · August 23, 2011, 06:53:31 AM

Happened again. Starts up, then cuts out and refuses to start. Today, I did notice that I do not hear the fuel pump cycle on-off upon powering on the ignition.

Bones · August 23, 2011, 09:18:14 AM

sounds like you may have water/heavy moisture in the gauge housing. big design flaw for monsters. They don't like water. Would make more sense if they were french bikes...

Vishwacorp · August 23, 2011, 09:30:13 AM

Sorry I don't fully understand. What is the "gauge housing"?

Howie · August 23, 2011, 09:35:13 AM

Quote from: avishw01 on August 23, 2011, 09:30:13 AM
Sorry I don't fully understand. What is the "gauge housing"?

Moisture in the instrument cluster can cause starting problems and long term damage to the cluster requiring replacement. Since your bike cranks it is unlikely the cause of your problem.

H-2 CHARLIE · August 23, 2011, 09:48:31 AM

Maybe some water in the gas ,from past rainy days .... change the gas out i bet its it .

Vishwacorp · August 23, 2011, 10:45:26 AM

It is a fresh tank of gas too. I'm thinking it could be the electrical components leading up to the pump. I'll report back when I get a chance to diagnose the issue.

Vishwacorp · August 27, 2011, 05:54:39 PM

I finally got a chance to diagnose the issue. The battery voltage is fine, and so are all the fuses and both the relays. The connector for the fuel pump under the tank is reading proper voltage so the pump is getting power too. I figure I'm gonna order this pump from California Cycleworks and put it in one when it gets here. And while I'm at it, I think I should replace the fuel filter too.

http://www.ca-cycleworks.com/ca-cycleworks-efi-fuel-pump-fuel-pumps

What do you guys think?

gfitzgi · August 31, 2011, 07:50:29 AM

I successfully cleaned my fuel pump with an ultra sonic cleaner. If I am to believe the shop guys that I talked to there is not much that can go wrong with a fuel pump. Saved me quite a bit of cash.

Just a thought.

Howie · September 01, 2011, 04:22:28 AM

Don't go replacing the fuel pump yet. Is the pump priming when you turn the key on? In it isn't you have no electricity to the pump. Electricity goes through the fuel sending unit to the pump and sometimes the failure is in the sending unit. If the pump primes have you checked fuel pressure? The fuel pump is also not affected by rain.

Vishwacorp · September 01, 2011, 07:09:05 AM

Thanks for the replies guys. This is where I am as of now with this issue. The pump does not prime (assuming that by prime, you mean the 3 seconds where it makes the humming noise then shuts off) when I turn the key on. Also worth mentioning is that the fuel pump was replaced on the motorcycle by the previous owner (although a dealer did the replacement) with that exact California Cycleworks model about a year ago. Since then there were a few months when the motorcycle was just sitting in the garage until I bought it.

Anyways, I checked the voltage at the connector that hooks up to the fuel tank (number 13 in the attached image). I disconnected it from the fuel tank and hooked up a multimeter to the powered side. There are two powered leads and two grounds in the connector so I assume one is for the fuel pump and the other is for the fuel sensor. One set gives me ~12 Volts and the other does not give me any voltage. Should I be getting ~12V for both the pump and the fuel level sensor? If so, how should I go about tracing this electrical problem?

I was thinking of hooking up the leads where I am getting 12V to the leads on the tank-side connector that go to the fuel pump to see if it would turn on. Is that an advisable thing to do?

Attached Image

Vishwacorp · September 17, 2011, 11:42:38 PM

So there is a new development in this case. After I couldn't figure it out, I took it to the dealer and they told me the fuel pump was busted but everything else seems fine. So in went a new 150 dollar fuel pump for California Cycleworks and at the same time, I got the bike fully serviced from the dealership which involved putting new belts, spark plugs, etc. and the motorcycle has been running fine since then... until tonight!

Around 200-300 miles later, the motorcycle cut out while I was riding it. I pulled over to the side of the road and turned the bike on and off and noticed that I do not hear the fuel pump again. I'm thinking the problem is electrical, but if so, what would cause the fuel pump that was in the bike before to fail? Surely, I couldn't have two fuel pump failures within a month! Could I?

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M620 Fuel Pump Issues