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Discussion Starter #1
I have a 1991 Vulcan 750 which starts and runs well.
After a good run it will restart without any problem UNLESS you put in on the side stand, when you get back on and try to restart, then all you will get is a very loud backfire.
You will have to wait at least 1/2 hour before it will restart.
Has anyone out there had this problem ?
 

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1986 VN750
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3,255 Posts
It sounds like your side stand safety switch is dirty. Search the forums for cleaning the kickstand safety switch, or bypassing it all together if that's your desired route.

Either that or you have a leaky float or something when you're on the side stand and it's flooding out a cyl.
 

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2000 VN 750 Senior Member
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2,494 Posts
I have a 1991 Vulcan 750 which starts and runs well.
After a good run it will restart without any problem UNLESS you put in on the side stand, when you get back on and try to restart, then all you will get is a very loud backfire.
You will have to wait at least 1/2 hour before it will restart.
Has anyone out there had this problem ?
I would think that using the side stand is flooding it from the tilt. If it was an electrical problem with the side stand safety switch it wouldn't make any difference how long it sits on the tilt. JMHO Try using the center stand and then restart it to see if the tilting is involved or not. Good luck.
 

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Linkmeister Supreme
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7,960 Posts
With the bike on the side stand look to see if the switch even touches it.
My side stand pivot point is worn enough that the leg does not touch the switch.

If yours does, put the scoot up on the center stand, with the side stand up and wiggle the switch lever around to determine if it is free to move, or stiff with dirt or jammed with a small piece of rock.

Spray a bit of penetrating oil in it and work until it is cleaned out and moves freely.

Then re-check for proper starting function.
 

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Discussion Starter #5
Thanks for the feed back.
The Side Stand Safety Switch plunger is moving in & out freely.
There is no problem restarting when hot using the Center Stand.
The problem occurs when the bike is hot and its put on the side stand, after sitting on its side stand for a few minutes, you mount the bike putting it into the upright position, try to restart and all you get is a very loud backfire.
The bike will not start until its cooled off sitting on its center stand.
I'm beginning to wonder if its a carb problem ???
 

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2014 KLR 650!
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3,361 Posts
Hot start has been an issue on here forever. I don't think there was ever a clear answer for why. try the ignition coil mode and the the other coil mod. My brain is not working. pin cushion coil mod....ah PICKUP coil mod.
 

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1986 VN750
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3,255 Posts
Goofy he starts fine on the center stand though, so makes me lean towards a carb float issue/flooding.
 

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for hot start problems....usually the culprit is a weak battery, or weak ignition.

Resolutions include:
AGM battery
Pickup coil mod
Coil mod to improve battery voltage to the coil.
 

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Overkill? Whats that?
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Mine started doing this a day before I sold it. I chalked it up to the battery being weak. / likely a float problem. But I would always use the center stand so meh. Check for voltage next time. Or let it sit on the side stand for a few minutes then put on the center stand for 30 seconds before cranking see if that makes a difference
 

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2000 VN 750 Senior Member
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2,494 Posts
.......Either that or you have a leaky float or something when you're on the side stand and it's flooding out a cyl.
I would think that using the side stand is flooding it from the tilt. If it was an electrical problem with the side stand safety switch it wouldn't make any difference how long it sits on the tilt. JMHO Try using the center stand and then restart it to see if the tilting is involved or not. Good luck.
Thanks for the feed back.
The Side Stand Safety Switch plunger is moving in & out freely.
There is no problem restarting when hot using the Center Stand.
The problem occurs when the bike is hot and its put on the side stand, after sitting on its side stand for a few minutes, you mount the bike putting it into the upright position, try to restart and all you get is a very loud backfire.
The bike will not start until its cooled off sitting on its center stand.
I'm beginning to wonder if its a carb problem ???
Goofy he starts fine on the center stand though, so makes me lean towards a carb float issue/flooding.
I am sticking with my original idea of flooding due to the tilt on the side stand as thtanner seems to be also. If you are not ready to really get into it just keep using the center stand until you have some time to possibly lay the bike up for a bit of time. For now I would use some carb cleaner spray and strong concentration of Seafoam in the next few tank fulls of fuel. Good luck and keep us updated.
 

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I am sticking with my original idea of flooding due to the tilt on the side stand as thtanner seems to be also. If you are not ready to really get into it just keep using the center stand until you have some time to possibly lay the bike up for a bit of time. For now I would use some carb cleaner spray and strong concentration of Seafoam in the new few tank fulls of fuel. Good luck and keep us updated.
I would agree that this is a float and high fuel level in the float chamber problem.
 

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Discussion Starter #13
The bike has a AGM Battery to answer the question asked.
I picked up a can of Seafoam and will advise the results.
Thanks again for all the input.
 

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My "very loud backfire" problem was instantly solved with a AGM battery. Slow starter for sure on a weak battery. BTW I think the EM hates backfiring.
 
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