Engine quickly dying and coming when I hit a bump

4708 Views 24 Replies 11 Participants Last post by Rolex, 8 mo ago

GriffinG

Discussion Starter · 9 mo ago

Hi y’all,
Ill be cruising on my 06 Vee and the bike will have moments when the engine briefly dies and quickly comes back like nothing happened. It gives this stuttering effect. I’ve noticed it much more in two situations- when i hit/come down from a bump or when when im accelerating. I’ve already ruled out my fuel pump as I just cleaned the filter and it’s passed a fuel flow test. I just checked the rear spark plug and it’s in very good shape. I haven't checked the front plug just yet.
Something tells me that it’s a loose connection somewhere, but im not sure. If so, what systems could it be in?Connection to the injectors or spark plugs are my first thoughts.
I should note that this bike has a power commander 3 and power commander speed healer. I didn’t hook them up, I just bought the bike like this haha

1 - 20 of 25 Posts

richlandrick

· #2 · 9 mo ago

First suspect - side stand cut-off switch.

Have you added a side stand foot or changed side stands lately? A heavy weight on the end of the side stand will cause it to bob don when you hit a bump. The side stand switch will kill the engine briefly when this happens.

Reactions: 5

strom_r0m

· #3 · 9 mo ago

reminds me of this thread

www.stromtrooper.com

Engine cuts out while standing up, solved

Somewhere I posted about the engine cutting out and tach dropping while standing up in rough country and our guesses about the kickstand switch were right. Just confirmed, in some specific situations with my boots back on the pegs, my heel hits the kickstand “hoop” causing the cut out. Now I can...

www.stromtrooper.com

www.stromtrooper.com

Reactions: 1

GriffinG

Discussion Starter · #4 · 9 mo ago

richlandrick said:
First suspect - side stand cut-off switch.

Have you added a side stand foot or changed side stands lately? A heavy weight on the end of the side stand will cause it to bob don when you hit a bump. The side stand switch will kill the engine briefly when this happens.

I was actually messing around in that area trying to change my front sprocket. What do you think the simplest solution is?

GriffinG

Discussion Starter · #5 · 9 mo ago

strom_r0m said:
reminds me of this thread

Engine cuts out while standing up, solved

Somewhere I posted about the engine cutting out and tach dropping while standing up in rough country and our guesses about the kickstand switch were right. Just confirmed, in some specific situations with my boots back on the pegs, my heel hits the kickstand “hoop” causing the cut out. Now I can...

www.stromtrooper.com

It assuring seeing multiple people thought of the stand kill switch at the same time. What do you purpose the simplest solution would
Be?

Sexyman

· #6 · 9 mo ago

Can you not bypass the kickstand to rule it out? Close or open the Circuit, whatever it requires for the bike to operate? Then go find some bumpy road?

dravnx

· #7 · 9 mo ago

Open your toolbox and get out your Mark I eyeball.
Look at the switch, move the side stand, make sure the switch is actuating properly. Make sure the connector is firmly on the switch.

Reactions: 4

Rolex

· #8 · 9 mo ago

First test is find a bump that makes the motor cut out each time you hit it.

Then use something to hold the stand in the up position and hit the bump a few more times.

No cut out means the problem has been found.

It can be caused by things like weak return springs, bent spring connection pins, worn pivot point, loose bolts or switch or some people push the stand down with their boot and they don't know it, this happens mostly when standing on the pegs.

Joining the two wires at the switch will bypass it.

Reactions: 5

bwringer

· #9 · 8 mo ago

These stupid kickstand switches just plain fail fairly often. It's a lousy unsealed design, immersed in the worst of road muck and chain lube slinging.

Sometimes you can flush the general filth out of the switch and get it functioning normally again. Some sort of plastic-safe contact cleaner, or plain old WD-40 combined with working it back and forth a whole lot until the flushes run clear.

As noted, a kickstand foot might cause issues, or one of the springs is missing, corroded, or weak.

Sometimes you can reposition the switch so it actuates a little later in the "swing", so minor bumps won't cause your bike to cut out.

Another fairly common "bump" issue, and easy and free to fix, is simply loose battery terminals. Worth checking. No one knows why garage gnomes sometimes feel the urge to sneak under the seat and loosen battery terminals.

See less See more

Reactions: 2

btadlock

· #10 · 8 mo ago (Edited)

My 04 1k started shutting down when I stood up, nearly throwing over the front, and they coming back to life when I sat back down, was truly puzzled until I realized my size 14 boot heel was pressing the "ear" the kickstand. Duh.

Reactions: 3

GriffinG

Discussion Starter · #11 · 8 mo ago

richlandrick said:
First suspect - side stand cut-off switch.

Have you added a side stand foot or changed side stands lately? A heavy weight on the end of the side stand will cause it to bob don when you hit a bump. The side stand switch will kill the engine briefly when this happens.

strom_r0m said:
reminds me of this thread

Engine cuts out while standing up, solved

Somewhere I posted about the engine cutting out and tach dropping while standing up in rough country and our guesses about the kickstand switch were right. Just confirmed, in some specific situations with my boots back on the pegs, my heel hits the kickstand “hoop” causing the cut out. Now I can...

www.stromtrooper.com

Sexyman said:
Can you not bypass the kickstand to rule it out? Close or open the Circuit, whatever it requires for the bike to operate? Then go find some bumpy road?

Rolex said:
First test is find a bump that makes the motor cut out each time you hit it.

Then use something to hold the stand in the up position and hit the bump a few more times.

No cut out means the problem has been found.

It can be caused by things like weak return springs, bent spring connection pins, worn pivot point, loose bolts or switch or some people push the stand down with their boot and they don't know it, this happens mostly when standing on the pegs.

Joining the two wires at the switch will bypass it.

bwringer said:
These stupid kickstand switches just plain fail fairly often. It's a lousy unsealed design, immersed in the worst of road muck and chain lube slinging.

Sometimes you can flush the general filth out of the switch and get it functioning normally again. Some sort of plastic-safe contact cleaner, or plain old WD-40 combined with working it back and forth a whole lot until the flushes run clear.

As noted, a kickstand foot might cause issues, or one of the springs is missing, corroded, or weak.

Sometimes you can reposition the switch so it actuates a little later in the "swing", so minor bumps won't cause your bike to cut out.

Another fairly common "bump" issue, and easy and free to fix, is simply loose battery terminals. Worth checking. No one knows why garage gnomes sometimes feel the urge to sneak under the seat and loosen battery terminals.

Unfortunately, I don’t think that the kickstand killswitch is the problem. I cleaned it out real good with some wd-40 and tied the kickstand to the passenger foot peg so it wouldn’t move when I rode. Even with the switch all cleaned out and tied to ensure that it stays pressed in, the bike is still cutting out. However, it feels like it looses power and becomes more jerky under acceleration now. Frustrating trying to track this problem. I’m again clueless, any clues?
Thank y’all very much for all the posts and help

Sexyman

· #12 · 8 mo ago

Did you bypass it?

Reactions: 2

Brockie

· #13 · 8 mo ago

Do not look past the switch until after you have bridged it, and still have the issue.
Then look under the seat for wiring that may be disturbed when the seat is compressed.

Reactions: 3

bwringer

· #14 · 8 mo ago

Agreed; I would not rule out the switch without bypassing it entirely. And also yep, check for anything that's getting compressed or contacted by the seat.

Same for the clutch switch as well; these fail early and often too, but of course they won't shut off the engine while underway.

Another potential issue is taking a good hard look at the Power Commander. The PCIII that came with my bike failed intermittently, causing much anguish. I finally disconnected the damn thing and the bike ran perfectly.

A loose battery connection also comes to mind. Weirdly common.

Reactions: 2

Rolex

· #15 · 8 mo ago

Ensure your battery cables are clean and tight.

They do work loose on bikes but unlike a car the motor will still start.

Reactions: 1

richlandrick

· #16 · 8 mo ago

Yep, as above. Don't rule it out until you by-pass it. And check the battery connection are tight and not corroded. All excellent advice from guys who know what they are talking about.

GriffinG

Discussion Starter · #17 · 8 mo ago

Sexyman said:
Did you bypass it?

Brockie said:
Do not look past the switch until after you have bridged it, and still have the issue.
Then look under the seat for wiring that may be disturbed when the seat is compressed.

bwringer said:
Agreed; I would not rule out the switch without bypassing it entirely. And also yep, check for anything that's getting compressed or contacted by the seat.

Same for the clutch switch as well; these fail early and often too, but of course they won't shut off the engine while underway.

Another potential issue is taking a good hard look at the Power Commander. The PCIII that came with my bike failed intermittently, causing much anguish. I finally disconnected the damn thing and the bike ran perfectly.

A loose battery connection also comes to mind. Weirdly common.

Rolex said:
Ensure your battery cables are clean and tight.

They do work loose on bikes but unlike a car the motor will still start.

richlandrick said:
Yep, as above. Don't rule it out until you by-pass it. And check the battery connection are tight and not corroded. All excellent advice from guys who know what they are talking about.

I bypassed the kill switch as prescribed to no avail. Unfortunately I ran out of daylight to check and see if maybe I’m squishing some wires under the seat but I’ll check tomorrow. The wires on the battery are hooked up nice and tight with no corrosion.
When y’all say the clutch switch, do you mean on the handlebars? What exactly do you mean? Having it be my PCIII would be a nightmare so I’d rather save that for a last resort hahaha
Stupid question, do I have to reply to everyone like I’m doing in these posts or do y’all get notifications for it? Thanks again for all the help

Brockie

· #18 · 8 mo ago

Yes, there is an interlock switch at the clutch lever to prevent attempting to start the bike in gear with the clutch out but this cannot be the cause of your issue.
As you have bridged the side stand switch this should be an intermittent wiring issue.

However, looking at your post #1 I see that you describe it as a "stuttering" effect. Can you expand on this? A wiring fault will kill the motor which will restart cleanly when the connection is re-established.
Stuttering indicates missed power strokes which may be fuel or ignition system issues.

Rolex

· #19 · 8 mo ago

I'm happy for you not to quote me, just post your reply and I will see it.

Your bike is well known for charging problems due to magnets moving it would be a good idea to check the charge rate at low RPM's, it may be struggling to supply the volts required to run the equipment.

On the 650 there is a big rubber boot covering a plug on the left side that has a lot of load going through it so it has connection problems, I don't know if the 1000 has the same issues.

GriffinG

Discussion Starter · #20 · 8 mo ago

A fuel or ignition problem was one of my first thoughts. When I say stuttering, I mean that the motor will briefly but rapidly loose rpm sporadically for about 5 seconds or less. Rpms normal, then significantly down, then normal, then significantly down until returning to normal. I’ll try to post a video so it’s more clear.
Upon further looking, my generation Vee seems to have had a bad run with stators. How could I test this? And where exactly is the boot on the left side you are talking about, and how exactly would I test that as well?

1 - 20 of 25 Posts

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