Hello,

This is my first post on VN750.com but I have been reading a lot recently on the forums. I recently bought a 1993 Vulcan 750 with around 18k miles. When I went the look at it the guy started it up with relatively no trouble. Took a couple seconds but it fire up. I took it for a ride and it ran fine so I bought it. A couple days later I tried to start it the first time at my house and had a lot of trouble. I ended up running the battery down and had to jump start it. It started right up when I hooked up the jumper cables.

So naturally I thought that maybe it was a bad battery. Luckily the battery was less than 90 days old and the guy I bought it from gave me the receipt. So this weekend I went and exchanged the battery. So I charged and installed it expecting to put it on and it fire right up. Wrong.....

The bike runs great once you get it started and I checked the battery with a voltage meter and the bike is charging when it is running. The problem is I can turn it off after I get it started and try to immediately try to start it back up and it won't. So I dont think it is the battery at this point. Every time I hook up jumper cables or my battery pack jump starter it fires right up. Is it possible that the ignition system is weak and only gets enough juice to start when the battery gets a boost? I did take all the spark plugs out and they didn't look like the bike is running lean or rich. They looked as they should and each of them was getting a spark. I guess I'm just wondering how strong that spark is.

Any help with this issue would be greatly appreciated!

I'm very frustrated with it at this point as I am supposed to take a big motorcycle trip with my cousin in September. I now have less than a month and an unreliable bike. I'm starting to think that I should have kept my 1982 Yamaha Virago....

Thanks,
Jeremy

Hang in there Jeremy, these are decent bikes, yours is just needing some tlc. If it runs good when you get it going and rides well, I don't think you've got anything major to deal with. Does it act differently when cold? Considering that it starts when you put a boost on it leads me to the coils and/or pick ups. You're getting a spark obviously but it may not be a hot enough spark when you're cranking the starter. 1st buy a set of iridium plugs. People on here swear by them. Haven't got them myself yet but plan to next season. 2nd, There are some threads on here that talk about coil modifications, running the power to the coils right off the battery instead of the harness, and the pick up mod, changing the distance on the ignition pick ups to a closer tolerance. Both of these mods mention easier cold and hot starting and overall improvement in performance. Take a look in the electrical forums for those and others will jump in and help, there are a lot of good people on

Oh, it might be good to try and look at the spark your coil is putting out. Maybe in a garage or at night? It should be blue, not orange.

Welcome to the Vulcan madness Chosen777.

If your present battery isn`t a Maintenance Free-AGM style similar to this DEKA, get one the next time you need a new battery:
http://cgi.ebay.com/ebaymotors/Deka-...item3eee173adb

You are going to want NGK Iridium DPR7EIX-9 plugs sooner than later, so try them first.
Many members have cured the hot and cold starting problems with just a new MF-AGM battery and the Iridium plugs.
If the bike still has starting issues try the following.

Ignition coil direct to battery mod:
https://www.vn750.com/forum/showthread.php?t=17276

Pickup coil adjustment with pictures:
https://www.vn750.com/forum/showthrea...ck+up+coil+mod
This mod may work by slightly advancing the ignition timing.

I did notice that the sparks weren't completely blue. They were orange with just a little bit of blue. Does this mean that they are not getting enough juice?

Thanks guys for the suggestions. I will have to check into the iridium plugs. I guess I need to get the voltage meter out and see if I'm losing power between the battery and the coils. If so could it just be a bad connection somewhere.

One thing I forgot to mention is I did see one of my plug wires sparking to the frame at one point. Could one plug wire shorting out prevent it from starting?

Sorry when it comes to electrical/ignition issues I'm a newbie....

OlHoss nailed it again...follow his advice and it should set you up fine... also if you are getting a spark on the frame from the plug wires that is bad!.. replace the wires asap!

Wow! I just check the price on the Iridium Plugs and they were about $9 a piece....Does that sound about right?

I can't recall for sure but I think I paid $7 each for mine.

Since I have a brand new battery I will probably wait on getting the sealed gel cell battery. I have had nothing but trouble with the wet cell batteries since I started riding. They usually only last a year or year and a half.

So if I am getting a weak spark how would I go about checking the voltage of the power getting to the spark plugs? Just pull the plug wire and stick the positive side of my meter in the plug wire and ground to the frame? Then hit the start button?

I payed about $8 for my Iridiums.

You already have some good advice, you should definitely get a new set of spark plug wires if they're "leaking".

On an unrelated note, when you get the bike up and running don't forget to do a spline lube before taking a big trip on it!