Charging problem caused poor acceleration?

[John Luttrell]

My old 92' voyager has run like a top until this spring, when one of my idle jets had gummed up over the winter.  Any way, I pulled the carbs, cleaned them up good, bench synced them, put it all back together and she ran like a top again; for a couple of days.  I was out for a ride and noticed that it was starting to run sluggish during hard acceleration, it was barely noticeable at first, but got worse as I rode for the house.

It felt like she was leaning out during acceleration, so I pulled the fuel pump and made sure it was pumping good and changed out the fuel filter.  After changing the fuel filter, I took her back out for a test run and I got the same thing; ran good, except during higher RPM's and hard acceleration.  So I headed back for the house to pull the carbs and double check the float levels, even though it had ran great for a few days after cleaning the carbs.

When I pulled up to the shop, I shut it off for a minute to open the shop door and found the starter would only turn over slow like the battery was dead.  So I grabbed my multi-meter and found the battery voltage to only show 11 volts static, which dropped to 6 volts when engaging the starter.  The battery is only two years old and I know it had a good charge on it the week prior; so I'm thinking I have a charging problem now and the bike running off only a weak battery is why it was running rough during hard acceleration and higher RPM's.

I have the battery on a trickle charger for the night and plan to do a test run with the battery fully charged in the morning; if the bike runs good at all RPM's then, I'll know that it is all tied into the charging problem and start down that path the next day I find time to work on her.  Have any of you gear heads ever had a low voltage condition cause a bike to run rough?

[TLRam1]

Have any of you gear heads ever had a low voltage condition cause a bike to run rough?

You bet, I can emulate that on a bike I currently have, low voltage the bike runs on one cylinder.

[dgc67]

It is the same, well similar, scenario when the bike won't start because the battery is low.  Not enough juice for a spark.

[John Luttrell]

Well, I went out and troubleshot the problem down to a bad alternator; with a fresh charge on the battery, I had good voltage down to it and 12 volts from the ignition switch side, but it would not charge at any RPM.  Disassembled it and found the brushes to be in good shape, so I'm sure it's the windings that's gone bad.

Looked around on the net for a replacement, to find Kawasaki wants $745.00 for one and that nothing else crosses to that part number.  I got a tip from one of the Voyager Forums about Carl Leo, who specializes in maintaining Kawasaki Voyagers.  So I contacted him and bought a rebuilt alternator from him for $250.00; hope I get another 50k miles on it, like I did on the last one.

[John Luttrell]

The new alternator came in the mail today and I got the bike put back together.  The alternator was the problem; it now runs like a new bike after all the things I changed and tuned before I realized it was a charging problem.

[TLRam1]

Thanks for the update John, good to hear you have it fixed.