this from the VN750 yahoo group might help
You might want to have your mechanic give this a try. I too have slight problem starting the bike when it is warm, but can usually get it going by choking half way, then rolling on throttle and backing off choke when it starts to catch.
But I found this a while back, somewhere, I don't recall where, and you might want to have your mechanic try this:
If I had more problems this summer I was going to give this a try, as well as relocating the RR, and new plugs, etc.
Possible solution to hard starting your VN7XX when hot.
Problem: Once my bike was good and hot, I would pretty regularly have problems restarting it after shutting it off for refueling, etc.... Once the starter was engaged, the bike would continuously turn over but never fire. After some e-mail discussion with Gary Versteegh from the main VROC board, I adjusted my pick up coils as described below. This seems to have eliminated my hard starting problems. This procedure may or may not solve your hard starting problems. Also, please note that the pick up coils are not designed from factory to be adjustable. This procedure requires modification to the stock components.
If you have any question, feel free to send me an e-mail to [email protected]
. I will be happy to answer any questions.
Adjustment of pick up coils.
Remove the 3 phillips head screws on the left side. This will allow you to remove the pick up coil cover. You will need to place something under the bike to catch the oil although oil loss will be minimal. A rag was enough for me. Once the screws are removed, the cover should either come right off or you may need to pull on it. Mine was on pretty good and I had to physically pull on it to get it loose. The three screws and the cover all have separate o-rings. Once the cover is off, you will see the two pick up coils mounted to the stator cover inside two holes. They are mounted at roughly the 9:00 and 11:00 o'clock positions. Behind the stator cover, there is a rotor. You may need to rotate the rotor using a socket wrench on the shaft bolt in the center to align the small "plate" on the rotor with one of the pick up coils so that you can measure the clearance. Once you have measured one, rotate the rotor again so that you can measure the other. Gary recommends .020 clearance. Mine were about .030 or more. To adjust the clearance, remove the two screws which secure the pick up coils to the stator cover. You will most likely need to slightly elongate or slot the holes in the "ears" of the pick up coil mounting brackets. Gary indicates that a chain saw file works well for this but I used a rotary tool with a small grinding wheel on it. You will also see that there are 3 small protrusions coming out of the stator cover that each of the mounting
"ears" of the pick up coils fit into for proper placement from the factory. You will most likely have to knock the one closest to the center off to be able to make the necessary adjustment. A sharp chisel works well for this although you may want to cover the holes in the stator cover with something to prevent the little piece from falling inside the engine. Once the protrusions are knocked off and the holes are elongated, it is time to put the pick up coils back on. Set them back in their holes and start the screws. Place your .020" feeler gauge between the coil and the rotor "plate" and tighten the screws. Once you are satisfied with the clearance, tighten down the screws and do the same with the other coil. Gary recommends that you use both an impact screw driver and lock tite on the screws. I don't have an impact driver but I did use lock tite. Once both are set, put everything back together and test it out. I don't have a digital camera or I would have taken and posted some pics but you can look through the pictures in the Clymer's manual to get an idea of what I am talking about. In my manual (I assume they are all pretty much the same) the pictures on pages 296 to 302 should give you an idea of what I am talking about.
> Does anybody know of a good mechanic in the North Carolina/South
> Carolina area (preferably near Charlotte)? I am having the problem
> with my Vulcan 750 sometimes either backfiring or not starting at all
> when trying to start the bike with a warm engine (but other times it
> starts up fine – it is very sporadic). It has been doing this ever
> since I bought the bike a year ago. I have taken the bike into the
> Kawasaki dealer, but they say that they can't fix the problem until
> they actually see the problem for themselves first hand, and, of
> course, every time they try to start it up with a warm engine, it
> starts just fine. I have given them copies of messages posted on
> this site from other people who have had the same problem, including
> messages that give suggested fixes to the problem, yet they won't
> seem to do any work on the bike until they actually see the problem
> with their own eyes. And the bike has been in the shop for over a
> month now. Since I am by no means capable of performing mechanic
> abilities myself, I'm hoping to find another mechanic that can fix
> this problem. Anybody know of one in the SC/NC area?