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Discussion Starter · #1 ·
I got a 86 Vulcan I bought it outta barn for 600$ It wouldn’t run. I used muriatic acid and got the rust out then I rebuilt the carbs and I specifically made sure the floats were free and I’ve ran it close to 100 miles and occasionally it starts flooding I got it to stop by hitting it with a screwdriver and it stopped but I think one of my problems is that the petcock won’t shut off ever, also it seems to be overheating at idle even though I did a coolant flush before even riding. And lastly it doesn’t want to start and cranks slow when warm but if I use a jump box I can get it started with a little work and unplugging the headlight. I just put a brand new battery in it and it was working fine but I think all the cranking killed it. I’m new to bikes and really just trying to figure it out but after putting in all the time I can the past couple weeks it’s really disappointing. Sorry the post is all over the place If anyone could give me some advice on these issues I think what I’m going to do about the petcock is to put inline switches on the fuel lines to the carbs because I don’t want to pay 120 for the oem petcock, and was thinking about running the with no thermostat so it doesn’t overheat any advice helps
 

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Discussion Starter · #2 ·
I’m really just trying to decide if I should keep working on the bike or just sell it and get something that isn’t so much a project
 

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First off welcome to the forum,

2nd, these bikes are known to have hot start issues but before you look to tackle that you might want to double check if the charging system is working. If that checks out there is a mod to the pickup coils that can help with the hot start issue.

If you suspect the petcock is a problem the in line valves would work but you don’t have much room and if the fuel lines run up hill at all you’ll have another issue with the bike starting to bog down.
As far as the overheating goes, what makes you think that? Does your gauge work? And have you noticed if the fan kicks on.
 

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Discussion Starter · #4 ·
First off welcome to the forum,

2nd, these bikes are known to have hot start issues but before you look to tackle that you might want to double check if the charging system is working. If that checks out there is a mod to the pickup coils that can help with the hot start issue.

If you suspect the petcock is a problem the in line valves would work but you don’t have much room and if the fuel lines run up hill at all you’ll have another issue with the bike starting to bog down.
As far as the overheating goes, what makes you think that? Does your gauge work? And have you noticed if the fan kicks on.
I was riding today and coolant was smoking and coming out the Overfill hose under the bike and the gauge was almost to the red until I started riding and I originally thought my stator was bad, but because i have ran it for 2+ hours I imagine that it’s not the stator
And I really hope it’s not cause I’m not comfortable doing the stator plate mod as the vendor doesn’t sell the plates anymore but I just checked and my coolant was kinda low so I topped it off and after I put on the shut off valves im going to try and ride again tomorrow but the mix of the hot start and the flooding it’s really making me want to throw in the towel
 

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Discussion Starter · #5 ·
I was riding today and coolant was smoking and coming out the Overfill hose under the bike and the gauge was almost to the red until I started riding and I originally thought my stator was bad, but because i have ran it for 2+ hours I imagine that it’s not the stator
And I really hope it’s not cause I’m not comfortable doing the stator plate mod as the vendor doesn’t sell the plates anymore but I just checked and my coolant was kinda low so I topped it off and after I put on the shut off valves im going to try and ride again tomorrow but the mix of the hot start and the flooding it’s really making me want to throw in the towel
And the fan does kick on
 

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I personally am not a fan of the stator plate mod myself. If the bike starts fine when it’s cold then I wouldn’t think the stator is part of your problem. I’m not 100% sure on the overheating but there’s folks on here who know a hell of a lot more than I do so just wait for one to chime in.

The pick up mod is not very difficult.
Here’s a thread I did last month when I did the mod


and here’s the thread I used to figure out how

 

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Have you checked your t-stat? Sounds like it isn't opening up.

It is my understanding that the pickup mod won't help speed up a slow crank, but rather helps the igniter properly sense when the motor is turning at very slow rpm. It's main usefulness is when a bike will crank hard, but still not start. It's possible that it would help enough to fire up the engine with a weak crank, but it doesn't solve the real problem.

You could be looking at a weak battery (new batteries have sometimes sat for a long time on the shelf before being sold), a bad starter, or even just dirty or loose electrical connections blocking the full battery amps from passing through the starter.
 

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Discussion Starter · #8 ·
Have you checked your t-stat? Sounds like it isn't opening up.

It is my understanding that the pickup mod won't help speed up a slow crank, but rather helps the igniter properly sense when the motor is turning at very slow rpm. It's main usefulness is when a bike will crank hard, but still not start. It's possible that it would help enough to fire up the engine with a weak crank, but it doesn't solve the real problem.

You could be looking at a weak battery (new batteries have sometimes sat for a long time on the shelf before being sold), a bad starter, or even just dirty or loose electrical connections blocking the full battery amps from passing through the starter.
I haven’t checked the thermostat I’m going to try and fix the flooding issue today by doing the inline fittings with switches. My coolant was low so I’m going to ride it up to temp and see what happens and it almost always has a slowish crank unless I have it hooked up to jumper cables for about 10 min and I still only get about 10-12 good cranks I think the starter is going bad and the battery is almost there. Like I said the bike has been sitting for almost 10 years I’m just trying to rig her up so she’ll take me to Baltimore for the o’s game on the 7th lol
 

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Discussion Starter · #9 ·
I personally am not a fan of the stator plate mod myself. If the bike starts fine when it’s cold then I wouldn’t think the stator is part of your problem. I’m not 100% sure on the overheating but there’s folks on here who know a hell of a lot more than I do so just wait for one to chime in.

The pick up mod is not very difficult.
Here’s a thread I did last month when I did the mod


and here’s the thread I used to figure out how

Also I read the thread but my pea brain isn’t understanding what I’m supposed to do, am I supposed to grind down the stator side of the bracket a little so it’s closer to the stator? Don’t wanna start grinding without clarification
 

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Yeah you’re correct, check my pics in the thread, but I’d look into what Thorn posted before I’d go that route. I didn’t notice you said “slow” crank initially.

modes it backfire when you’re trying to start it? That’s a good indicator of a weak battery
 

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Discussion Starter · #11 ·
Yeah you’re correct, check my pics in the thread, but I’d look into what Thorn posted before I’d go that route. I didn’t notice you said “slow” crank initially.

modes it backfire when you’re trying to start it? That’s a good indicator of a weak battery
Yea she goes off like a cannon sometimes when trying to start it
 

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Discussion Starter · #13 ·
I got a new battery less than a month ago, but I’m going to return and replace that today
 

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Discussion Starter · #16 ·
Everyone here swears by the AGM style for higher cranking amps compared to the traditional lead cell.
The original battery was an agm but it went completely dead as my stator wasn’t working or so I thought, and it just cranking till dead over and over, and now I think of it when the battery was brand new it didn’t crank particularly fast
 

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[QU
Could the starter relay be the problem or should I just jump into the motor itself
No, if the starter kicks in, it's not the starter relay.
 

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Discussion Starter · #19 ·
So looking into the bike it rode fine all day today but still won’t hot start. if I let it cool down it will start no problem. now issues I noticed that my radiator fan was broken off of the motor and my upper radiator hose is completely dry. I ordered a new radiator along with the fan and changing the thermostat tomorrow I’m thinking the thermostat is stuck closed, it only runs hot when sitting so it’s probably just the fan but imma put a 180 Honda thermostat in it along with everything else and hopefully that fixes it. I also ordered a starter rebuild kit and starter relay just because it was so cheap, I’ll update when I put everything on, I imagine that will fix it cause from what I understand the water pump kinda can’t fail unless it’s broken off which I would obviously know.

p,s installed new agm battery but still has a relatively slow start and backfires when hot starting
 

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This is what I was dealing with, this video is from February, temps in the 40s and I only warmed the bike up and rode a little over a mile before pulling over to turn on my camera. You’ll notice I’ll pull the choke and that helps, but since the mod this has disappeared. There’s two schools of thought on the hot start issue, some think electrical, some think fuel. In my case the electrical mod helped.

 
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