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Bike runs great...then misfires...then, minutes later...


VtwinStorm

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...when I'm pushing it up a hill w/a 7 degree grade, she fires up and now is idling happily in my open garage?!

WTF?!

After a raft of work totaling $2k on my invoice, this machine should at least not be misfiring, no?!

Fresh fuel, tune up, valves, plugs, requested fuel filters...what gives?

I'm afraid to ride her now, for fear of being stranded.

Guess my celebrating was premature?

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"fresh fuel" often means-- added to the old fuel left at the bottom of the tank. If it sat awhile before purchase, and under less than desirable conditions, it may also include condensation. Hopefully the tank was drained and rinsed prior, then you can rule out water. Sounds like water to me.

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I agree with footgoose. It could be something else, but it really sounds like water in the fuel tank. I had that on my Buell. The water sits at the bottom of the tank. When I would go up hill the water would run to the back of the tank where the fuel intake for the fuel pump was. It would misfire. Then once level or downhill again it would stop it after a minute or two.

One of the joys of buying a used bike this old is fixing all the stupid stuff that is wrong with it. But this could be an easy fix if it is indeed water. Drain the fuel tank into a translucent fuel can and look for water in the bottom. If there is water in the fuel it will settle to the bottom.

While paying someone a bunch of money to fix a motorcycle can work, it is often better to learn how to do it yourself. And with the smart guys around here and all their experience you can learn. If I can learn from these guys you can.

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Vote number 3 for water in the tank. Let me tell you a story.. A guy called me one time saying the 65 hp engine in his Luscombe would be purring along, then suddenly miss, then continue running fine. He was getting afraid to fly it, and asked if I had any ideas. I said, "Sure. You didn't drain your float bowl during the last Annual inspection, did you?" Silence. "Er.. no." :)

As mentioned above, water goes to the lowest point in the fuel system. Once it is in a float bowl, it stays there. Airplanes have sump drains and a gascolator that should catch the water..if.. the driver faithfully drains them before the first flight of the day. It's certainly not unusual for a motorcycle to have water sitting in the bottom of the tank.

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Hopefully just water, if not I woud ride it some more, see whats happening.   More clues are good, and don't forget if you like the character of the bike, you shoud be on the way to learn your V11.

Cheers Tom

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5 hours ago, VtwinStorm said:

...when I'm pushing it up a hill w/a 7 degree grade, she fires up and now is idling happily in my open garage?!

WTF?!

After a raft of work totaling $2k on my invoice, this machine should at least not be misfiring, no?!

Fresh fuel, tune up, valves, plugs, requested fuel filters...what gives?

I'm afraid to ride her now, for fear of being stranded.

Guess my celebrating was premature?

Have you had the fuel tap out and checked the fuel filter on the tap? How much fuel is in the tank? The last 3 litres are unusable by and large and your symptoms are also aligned with running out of fuel. Spluttering on the flat and running again if you point it up hill when the fuel runs back to the fuel tap pickup.  +1 on the water as well.

Ciao

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This year I've been fairly responsible; since I haven't had enough time to take any longer trips I've been able to go to the boat ramps and a certain co-op and put exclusively ethanol free gasoline in my beast and add a water dispersion additive for extra mojo. 

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Think I found the offending parts responsible for my being left stranded.

Appears the left throttle linkage caused two connectors, one for fuel (?), one for the left fuel pump (?) to BOTH come loose.

After some fiddling (thankfully, didn't have to remove the tank), they are both connected again.

I will use zip ties to add clearance from the linkage tomorrow and then, cautiously, ride her a few blocks several times.

Glad it was obvious what it was, and why it was intermittent---because the connectors were both barely connected!

Whew. My first Guzzi crisis cleared, if she runs well tomorrow...

guzzi lines edit.jpg

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Not the pump, but the fuel level sensor and the electric petcock. That electric fuel tap was only fitted to the early V11 Sports and many of us decided to go to the manual option to eliminate that point of failure.

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9 minutes ago, Chuck said:

Are they still using the same connectors that better not be reversed?

Yes, doesn’t that fry the fuel level sensor?

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1 hour ago, Chuck said:

Are they still using the same connectors that better not be reversed?

Thankfully....no. Connectors are both totally different, even my stupid self can't screw it up as they won't match.

I fired her up in the garage just now...on high enrich/choke...seems fine.

It is very wet outside, so my road test will have to wait until tomorrow.

I love this machine, and enjoy riding it so much.

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Just so I clear up any confusion: like any quality long-term relationship,  I'm willing to put in the work for my baby.

She idled like she had two cylinders after I reattached both conectors...sounds amazing. I enjoy the Mistrals in sound and appearance. They so compliment this machine. 

I'm still obsessed and in love with the V11 Sport.  Can't wait to really scrub in my Diablo IIs tomorrow!

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UPDATE: Took her for a run, a long run.

She's running perfectly again.

Slight hiccup, but what a machine.

The V11 Sport is criminally undervalued.

She's a bargain modern classic with such soul!

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