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Discussion Starter #1
I am tired of the hard "hot start" issue on these bikes (sometimes), so I invested in NGK Iridium Spark Plugs (in addition, the pickup coil mod is on my to-do list for this year). I'm a very data driven individual and I like to see pictures. I used the slow motion video recording feature of my iPhone 8 to capture some screen shots of OEM versus NGK Iridium. I did this both in low light (left column) and bright light (right column). The top row shows OEM and the bottom row shows Iridium.

My untrained eye picks up some differences between OEM and NGK. In my opinion, I see the NGK spark as longer and brighter. Also during the slow motion video the NGK spark seemed very straight and consistently hit the same point of the tip. Whereas sometimes the OEM spark looked to be at a sharper angle between the central electrode and the tip.

What do y'all think? I look forward to trying this on the road this weekend. And I look forward to the pickup coil mod later!


53136
 

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Discussion Starter #2
I am tired of the hard "hot start" issue on these bikes (sometimes), so I invested in NGK Iridium Spark Plugs (in addition, the pickup coil mod is on my to-do list for this year). I'm a very data driven individual and I like to see pictures. I used the slow motion video recording feature of my iPhone 8 to capture some screen shots of OEM versus NGK Iridium. I did this both in low light (left column) and bright light (right column). The top row shows OEM and the bottom row shows Iridium.

My untrained eye picks up some differences between OEM and NGK. In my opinion, I see the NGK spark as longer and brighter. Also during the slow motion video the NGK spark seemed very straight and consistently hit the same point of the tip. Whereas sometimes the OEM spark looked to be at a sharper angle between the central electrode and the tip.

What do y'all think? I look forward to trying this on the road this weekend. And I look forward to the pickup coil mod later!


View attachment 53136
Forgot to mention, OEM is a new Autolite copper spark plug. Installed ~Oct-2020. 500 miles or less of use. :)
 

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Don't know if the iridium spark is stronger, but for a few bucks more than standard plugs, you get a plug good for 100,000 miles or more. My bike always started easily, cold or hot, but I switched to iridium shortly after I got the Vulcan.
 

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I just did the pick up mod about two weeks ago and the stating improvement so far is more than expected. The iridium plugs can not hurt in any way so since you have them, use them. I personally wish I did the updates in stages but I did the mod and changed the plugs in the same day. I don’t know how “hot” the bike really was when I tested it after the mod, but the bike started up and previously it would start giving me trouble after a short ride to a store so the improvement seemed immediate.
 

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Discussion Starter #5
Don't know if the iridium spark is stronger, but for a few bucks more than standard plugs, you get a plug good for 100,000 miles or more. My bike always started easily, cold or hot, but I switched to iridium shortly after I got the Vulcan.
Yeah, that's another pro. Won't have to worry about plugs for basically the life of the bike. :)
 

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Discussion Starter #6
I just did the pick up mod about two weeks ago and the stating improvement so far is more than expected. The iridium plugs can not hurt in any way so since you have them, use them. I personally wish I did the updates in stages but I did the mod and changed the plugs in the same day. I don’t know how “hot” the bike really was when I tested it after the mod, but the bike started up and previously it would start giving me trouble after a short ride to a store so the improvement seemed immediate.
What tool did you use to make the adjustment to the pickup coil? Did you measure with a caliper or did you eye ball it? And when you took the cover off, did any substantial amount of oil come out? I was planning to wait until the next oil change but if only a little oil comes out I'll do it sooner. :)
 

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1989
What tool did you use to make the adjustment to the pickup coil? Did you measure with a caliper or did you eye ball it? And when you took the cover off, did any substantial amount of oil come out? I was planning to wait until the next oil change but if only a little oil comes out I'll do it sooner. :)
Very little oil comes out when you remove the side cover. Just any drips left on the cover from last time you ran it. Of course, do this while on the center stand!

My first VN750 (1989) never had hot start issues. I did the pickup coil mod anyways. It's supposed to theoretically also give a slight boost in performance (unnoticeable to the butt dyno). Later when I was having charging issues, I did the direct coil mod to try to fix a different issue.

My current VN750 (2005) has bad hot start issues. I transferred the direct coil mod over to it with no change. I put in iridium plugs with no change. If I turn off the petcock a couple blocks before shutting off, it starts right up when hot. If I hold the throttle fully open, it starts right up when hot.

Based on other's experience, I suspect multiple causes for hot start issues. Mine appears to be 100% fuel/carb related, but others have said that this mod, or an AGM battery fixed it. It's not a hard mod, and it won't hurt anything.
 

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Discussion Starter #8
1989
Very little oil comes out when you remove the side cover. Just any drips left on the cover from last time you ran it. Of course, do this while on the center stand!

My first VN750 (1989) never had hot start issues. I did the pickup coil mod anyways. It's supposed to theoretically also give a slight boost in performance (unnoticeable to the butt dyno). Later when I was having charging issues, I did the direct coil mod to try to fix a different issue.

My current VN750 (2005) has bad hot start issues. I transferred the direct coil mod over to it with no change. I put in iridium plugs with no change. If I turn off the petcock a couple blocks before shutting off, it starts right up when hot. If I hold the throttle fully open, it starts right up when hot.

Based on other's experience, I suspect multiple causes for hot start issues. Mine appears to be 100% fuel/carb related, but others have said that this mod, or an AGM battery fixed it. It's not a hard mod, and it won't hurt anything.
Alright! Good to hear. I was going to wait until oil change to do this mod but now it seems like I don't need to. I'll be doing this soon, probably this Spring sometime. First I want to get the new MOSFET R/R from Roadster Cycle on and make sure charging voltage is nominal before I start a new project.

What tool do you think is best to for this pickup coil mod? Or what tool did you use? A dremel with a cone/wheel style grinder?
 

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What tool did you use to make the adjustment to the pickup coil? Did you measure with a caliper or did you eye ball it? And when you took the cover off, did any substantial amount of oil come out? I was planning to wait until the next oil change but if only a little oil comes out I'll do it sooner. :)


I used a dremmel with a diamond tip bit to burr the bracket, and I used the a feeler gauge to measure the gap to 0.020. Both from harbor freight for pretty cheap (maybe $15 for both). Burr a notch in the bracket so it’ll fit around the nub on the case and egg the hole on the left side to give you room to adjust.

pics below

And as Mr Pittenger said, center stand to minimize oil (y)
 

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Spark on the iridium has a lighter blue spark the full length of the spark.

Spark on the OEM has darker blue in the center with the lighter blue only on each end of the spark.

Need the pickup coil mod on mine, so far it's the choke that gets mine running on a hot-no-start.

When I first did the Two Wire mod, I thought hot-no-start was gone, but it soon struck again.
 

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Discussion Starter #11
I used a dremmel with a diamond tip bit to burr the bracket, and I used the a feeler gauge to measure the gap to 0.020. Both from harbor freight for pretty cheap (maybe $15 for both). Burr a notch in the bracket so it’ll fit around the nub on the case and egg the hole on the left side to give you room to adjust.

pics below

And as Mr Pittenger said, center stand to minimize oil (y)
Thanks! I'll be doing this soon and I'll report back with an update.
 

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My 2006 was dead stock when I bought it in 2015. (Only 2046 original miles.) Tried to run it as manufactured, but by mid summer I had to do something about the hot start problem. Rewired the coils and put in iridium plugs. Haven't had a problem since.
 

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Discussion Starter #14
Holding the throttle open a quarter turn worked for me to avoid hot start issues.
Same here. But also I've gotten HUGE pops of the air/fuel probably combusting in the exhaust. So I'll be doing the popular pickup coil mod shortly...probably tonight. I'll report back with my conclusion. :)
 
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