Author Topic: V7 won’t run help please  (Read 1162 times)

Offline mcguyver

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V7 won’t run help please
« on: May 23, 2021, 03:57:26 PM »
Anyone have any idea what might be going on here. Bike starts immediately revs to 4 k then stalls. Was running fine one day next morning this. 2011 V7 racer with 65k klms
Any help appreciated.
Hopefully this video works.
https://www.facebook.com/groups/135549259846493/permalink/3712043322197051/

Offline Huzo

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Re: V7 won’t run help please
« Reply #1 on: May 23, 2021, 04:24:11 PM »
First of many guesses.
Not holding fuel pressure. Split/ leaking/ loose hose on the internal fuel pump.
Tank off, pump out, check.

Offline guzzisteve

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Re: V7 won’t run help please
« Reply #2 on: May 23, 2021, 05:46:39 PM »
OR the 1/2 plastic filter split.
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oldbike54

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Re: V7 won’t run help please
« Reply #3 on: May 23, 2021, 09:52:49 PM »
 If the filter or hoses have failed , how is it starting at all ?

 Dusty

Wildguzzi.com

Re: V7 won’t run help please
« Reply #3 on: May 23, 2021, 09:52:49 PM »

Offline berniebee

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Re: V7 won’t run help please
« Reply #4 on: May 23, 2021, 10:17:42 PM »
Start with the easiest things to check. Are there any vacuum hoses loose or disconnected? Any wiring connectors loose? For both vacuum and electrical, it's a good idea to pull apart plugs/connections and reconnect them. Battery terminals tight?
Turn the key to on with the bike in a quiet place. You should be able to hear the fuel pump operate briefly, then stop.

Could be an air leak- did you just replace the air filter?

Did the bike fall over recently? Check everything carefully on that side.

Otherwise, the problem can be due to one of several sensors or the fuel pump. Some serious troubleshooting may be needed.


Offline Huzo

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Re: V7 won’t run help please
« Reply #5 on: May 24, 2021, 12:19:18 AM »
If the filter or hoses have failed , how is it starting at all ?

 Dusty
Pressurising enough to start but insufficient for higher rev demand ?

Online sign216

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Re: V7 won’t run help please
« Reply #6 on: May 24, 2021, 04:14:15 AM »
It does seem like it's not getting fuel, but that's just a Swag.  After starting and dying, will it immediately re-start?

After dying, when you crank it again do the plug have spark?  (for this test pull a plug, lay it on the frame to ground it, and look for the spark.  The electronic ignition will break if it's not grounded back to the circuit)

Also, after dying, and try cranking again, pull a plug and sniff it for fuel.  Does it smell of gasoline?

Joe
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oldbike54

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Re: V7 won’t run help please
« Reply #7 on: May 24, 2021, 08:54:14 AM »
Pressurising enough to start but insufficient for higher rev demand ?

 Sorry mate , that simply doesn't explain why it revs to 4K and then dies . The hose and filter failures I am aware of resulted in the engine not starting at all . This really sounds like a sensor failure .

 Dusty

Offline Huzo

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Re: V7 won’t run help please
« Reply #8 on: May 24, 2021, 08:58:02 AM »
Sorry mate , that simply doesn't explain why it revs to 4K and then dies . The hose and filter failures I am aware of resulted in the engine not starting at all . This really sounds like a sensor failure .

 Dusty
Hmmm..
Will be interesting to finally find out.. :popcorn:

Offline Wayne Orwig

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Re: V7 won’t run help please
« Reply #9 on: May 24, 2021, 09:01:54 AM »
It is very unlikely to be a fuel problem. It is getting too much air to rev like that by itself. Somewhere there is a major air leak, a stuck idle control valve (if there is one) or a stuck throttle servo (I don't think it has that).
« Last Edit: May 24, 2021, 09:03:12 AM by Wayne Orwig »
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Offline Kiwi_Roy

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Re: V7 won’t run help please
« Reply #10 on: May 24, 2021, 02:43:11 PM »
I think it might have backfired and blown the throttle body apart, that happened to mine, if so it's just a matter of joining the throttle body to the manifold again.
It might be sitting together, it starts then leaks letting too much air in.
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Offline Huzo

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Re: V7 won’t run help please
« Reply #11 on: May 24, 2021, 03:45:11 PM »
It wasn’t obvious (to me), that the second startup rev to 4,000 was uncommanded.
So it revved up there by itself ?
Does it run a stepper that you can disconnect and blank off for test purposes or pull the electrical plug to disable it ?
I am still somewhat perplexed as to why it will rev to mid range for a few seconds, then something changes to make it cut. I initially thought that you held the throttle on in the second instance.
Does the bike ever stubbornly refuse to start at all ?

Offline Kiwi_Roy

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Re: V7 won’t run help please
« Reply #12 on: May 24, 2021, 05:09:12 PM »
REVISED
When my bike was less than 1 Year old I was having trouble with the alternator, it had shorted windings, this caused the battery to go flat.
On starting one time it backfired blowing the throttle body off the manifold, I wasn't aware of what had happened, it would start and rev up as you describe because air would suck in through the gap then it would stall.
When I finally got it to start and run I dropped it off at the dealership nearby.
They told me the throttle body had popped off.
Don't try and run it in this condition, the extra fuel can cause the catalytic converter to overheat and catch fire.
« Last Edit: May 25, 2021, 12:44:02 PM by Kiwi_Roy »
17 V7III Special
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Half a V9 Roamer

Moto Guzzi - making electricians out of riders since March 15 1921

 

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