starter won't stop! (indep. of kill + ignition position)

More
24 Jul 2006 17:34 #64369 by jfl
Hi all,

My first post (I think :)

I have a 1975 KZ400 (D2 is it? The non-"special" version)

It's pretty beat up, but gets me from A to B ok.

Today *while* riding, my starter just started spinning.

I pulled off, hit the kill and turned off the key, no effect, starter still cranking away.

Eventually I disconnected the battery to avoid burning out the starter(? or any other damage) & pushed it somewhere I can leave it overnight.

I'm *really* not very mechanically inclined (yet!) so keeping things basic would be helpful. I have a comp. eng. background so I know a little about electronics, though I'm mostly a s/w guy (& I'm better with digital logic than housewiring :-P).

Any suggestions on how to troubleshoot this?
My first hope was to disconnect the starter and use the kick, but I'm not even sure where to do that (wasn't able to find it at the roadside with the bike in any case). What faults seem likely? Ignition switch? starter somewhere? What kind of fault?

I use it for transportation so I'm hoping to get it on the road ASAP (safely) then improve from there.

*Many* thanks for any suggestions!

[going to try reading manual electrical schematics now for the first time in years...]

Joe.

Please Log in or Create an account to join the conversation.

More
25 Jul 2006 06:29 #64517 by trippivot
solenoid trigger wire or the wire to the starter button
(same) is pinched to a ground it's either that or the solenoid is gone bad

disconnect the little wire at the solenoid
reconnect the battery

if the starter goes without control it is the solenoid

if it is silent it is the wire pinched somewhere along the way to your handlebar

if that doent help someone here will have a good idea I haven't thought of

Please Log in or Create an account to join the conversation.

More
25 Jul 2006 11:45 #64592 by apeman
I am betting that you have a failed starter solinoid. If you had a problem in the (lower amperage)starter button circuit, it is likely that the clutch handle lock-out switch would prevent the starter from being activated (unless you are holding in your clutch this whole time, which I doubt). Thus, I would look to the higher amperage solinoid actuated circuit to the starter as the likely source of the problem, and the only component in that part of the system (over than the starer) is the solinoid.

If you have a spare, I would try replacing the solinoid. If you do not, simply disconnect the wire connecting the solinoid to the battery (+ side), and you will be able to still ride your bike using your kick starter until you finish trouble-shooting your problem.

Post edited by: apeman, at: 2006/07/25 14:47

Petaluma and Truckee, CA -- member since Jan. 23, 2003;
PREVIOUS KZs: 1980 KZ750H with 108,000 miles; 1980 KZ750E with 28,000 miles; and KZ750H street/cafe project, all sold a few years back.

This is what I do for fun, not for work. It is art, with a little engineering thrown in.

Please Log in or Create an account to join the conversation.

More
25 Jul 2006 11:45 #64593 by apeman
*#%!% double post!!!
/

Post edited by: apeman, at: 2006/07/25 14:46

Petaluma and Truckee, CA -- member since Jan. 23, 2003;
PREVIOUS KZs: 1980 KZ750H with 108,000 miles; 1980 KZ750E with 28,000 miles; and KZ750H street/cafe project, all sold a few years back.

This is what I do for fun, not for work. It is art, with a little engineering thrown in.

Please Log in or Create an account to join the conversation.

More
25 Jul 2006 16:50 #64674 by jfl
Hi trippivot and apeman!

Thanks for the quick responses and suggestions (& explanations)! Always nice to have when you're without wheels :-)

Right on the money it seems.

I tested as tippivot suggested and the starter still ran. The simplified starter circuit schematic in the Clymer manual I have was handy - pretty simple circuit, though I shamefully wasn't certain what was what (solenoid, a rectifier or regulator nearby, ...) until I looked at it a bit.:P.

I pulled the solenoid for finding a replacement part & taped everything up well. I'm not sure of the specs yet, but I'm guessing it's reasonably generic? I also see a couple screwes on the head so I might try to open it up & see if the fault is obvious and/or repairable. I'm guessing not, but maybe? (wind, wind?)

Glad I have wheels again in any case!
Hope my starter (& everything else!) is still ok.


One thing I wasn't sure about: I checked the voltage to the solenoid trip leads with key on, run/kill switch on "run" & starter button depressed (after removing the solenoid) and got 0 volts DC which seemed strange. Is it an A/C solenoid or is that otherwise normal? I'm probably forgetting something I know here.


Man, there is *so* much to fix up on this old bike, yet I think it's mostly pretty repairable & at 30+ years old, I'd like to keep it & maybe even restore it at some point if I can learn enough.


Thank you *very* much again for the quick responses!


Joe.

Please Log in or Create an account to join the conversation.

More
25 Jul 2006 19:43 #64719 by apeman
jfl wrote:

One thing I wasn't sure about: I checked the voltage to the solenoid trip leads with key on, run/kill switch on "run" & starter button depressed (after removing the solenoid) and got 0 volts DC which seemed strange. Is it an A/C solenoid or is that otherwise normal? I'm probably forgetting something I know here.


Joe, You will have 0 volts to the solinoid trip wire using your proceedure UNLESS you also hold the clutch handle in. Did you remember to do that?

The solinoid is all DC. My guess is that your solinoid contacts are welded closed. That can happen, expecially if they were not making full clean contact, and were arcing. That is the same principle that an "arc welder" is based upon. The arcing produces a great amount of heat exactly at the point where the arc meets the contacts. If the contacts are not totally trashed, you may be able to clean them off, and rub them shiney with some steel wool or emery paper. Then bend the contacts so they make full hard contact when the solinoid switch is activated. Or better yet, replace the thing. They are cheap, and you could find a generic version at your local auto supply.

Post edited by: apeman, at: 2006/07/25 22:45

Petaluma and Truckee, CA -- member since Jan. 23, 2003;
PREVIOUS KZs: 1980 KZ750H with 108,000 miles; 1980 KZ750E with 28,000 miles; and KZ750H street/cafe project, all sold a few years back.

This is what I do for fun, not for work. It is art, with a little engineering thrown in.

Please Log in or Create an account to join the conversation.

Powered by Kunena Forum