Vt250 87 (New Zealand Market) Major Electrical Problem

Chasing electrical bugs can drive you crazy! Here is where you can get your sanity back.

Vt250 87 (New Zealand Market) Major Electrical Problem

Postby Katalyst881 » Thu Aug 24, 2017 3:01 am

So ill start this story of with how I got this bike, About a month ago I bought a 87 VT250 off a local buy sell page for very cheap. I noticed that i got this bike vary cheap so I sent it to a local motorbike mechanic to get a service done, i got Oil, spark plugs and the tank sealed due to some minor rust in the bottom of the tank. When i received the bike back everything was good. A couple of days ago i took the bike for a long ride, about 3 hours in the headlights started to flicker between low beam and high beam for a couple of seconds and about 3 minutes later the bike lost all power and died. so we transported it home and decided to have a look at it and noticed the battery had exploded so i ordered a new one and put it in. The bike started up for about two seconds then died suddenly with the ignition fuse popped as well. so I replaced the fuse and tried starting again and it wouldn't wind over. I noticed a faint burning smell coming from the CDI, So i took the cdi apart and saw that the cdi had a couple of black marks So the question is what would cause all of this? :?:
Katalyst881
 
Posts: 5
Joined: Thu Aug 24, 2017 2:42 am

Re: Vt250 87 (New Zealand Market) Major Electrical Problem

Postby Katalyst881 » Thu Aug 24, 2017 3:02 am

And i have noticed the cdi and the r/r has been relaced before i had gotten it
Katalyst881
 
Posts: 5
Joined: Thu Aug 24, 2017 2:42 am

Re: Vt250 87 (New Zealand Market) Major Electrical Problem

Postby John Hilmer » Thu Aug 24, 2017 5:17 am

The symptoms sure sound like a charging circuit issue. I would go through the tests for the alternator and regulator/rectifier.

An unregulated voltage from the alternator can burn the Engine Control Unit, so it may have suffered. If you get the charging circuit sorted out and have no spark the ECU is probably fried.

John
Lord help me to be the man my Labrador thought I was.
It's never too late to have a happy childhood ...
John Hilmer
Moderator
 
Posts: 1979
Joined: Tue Jun 05, 2012 7:29 am
Location: Scotts Valley, Ca.

Re: Vt250 87 (New Zealand Market) Major Electrical Problem

Postby Katalyst881 » Thu Aug 24, 2017 5:57 am

So how would i go about testing these things, i have and cdi and r/r coming in the mail but i don't want to destroy those as well.
Katalyst881
 
Posts: 5
Joined: Thu Aug 24, 2017 2:42 am

Re: Vt250 87 (New Zealand Market) Major Electrical Problem

Postby Katalyst881 » Thu Aug 24, 2017 10:46 am

Update: When the kill switch is off it doesn't blow the ignition fuse but as soon as i switch it, it blows the fuse. also the headlight blew when the battery exploded i have replaced the headlight with no change
Katalyst881
 
Posts: 5
Joined: Thu Aug 24, 2017 2:42 am

Re: Vt250 87 (New Zealand Market) Major Electrical Problem

Postby squirrelman » Thu Aug 24, 2017 1:11 pm

we've seen it happen before: if the r/r goes bad it can result in over-charging the battery and anything else. you'll need a multimeter to check that the charging voltage (measured at battery terminals with engine @5000 rpm) to determine that the voltage doesn't go much above 14.5 volts. :o

be sure to clean up the battery mess with cold water+baking soda to eliminate the acid that will cause rusting.
User avatar
squirrelman
 
Posts: 714
Joined: Wed Jul 18, 2012 1:57 pm
Location: Buffalo, NY USA

Re: Vt250 87 (New Zealand Market) Major Electrical Problem

Postby John Hilmer » Thu Aug 24, 2017 3:07 pm

The continuity and resistance checks for the alternator and R/R are shown in the service manual.

You do have a service manual, right?

With that and a multi-meter all will become clear.

The destroyed battery indicates it was receiving too much voltage which could or could not be rectified, so the alternator may still be OK, but it needs to be checked.

You need o check both the alternator and R/R before running the engine other wise new parts could be ruined as well as the ECU if it isn't already fried.

I recall that there is a service manual available on this board somewhere, but I don't remember where it is. Perhaps someone else can help you find it if you can't do so.

Keep us informed and we'll help if we can.

John
Lord help me to be the man my Labrador thought I was.
It's never too late to have a happy childhood ...
John Hilmer
Moderator
 
Posts: 1979
Joined: Tue Jun 05, 2012 7:29 am
Location: Scotts Valley, Ca.

Re: Vt250 87 (New Zealand Market) Major Electrical Problem

Postby ExTex77 » Thu Aug 24, 2017 8:38 pm

Here is the forum link to the service manual.
http://vtr250.org/forums/viewtopic.php?f=6&t=50


ride safely
ExTex
1989 Honda VTR250 & 2015 Honda CB500FA
Wife rides a Burgman 200 scooter and I enjoy riding it also
ExTex77
 
Posts: 436
Joined: Mon Jun 04, 2012 6:47 pm
Location: S.E. Arkansas

Re: Vt250 87 (New Zealand Market) Major Electrical Problem

Postby Katalyst881 » Fri Aug 25, 2017 5:21 am

Update: So I tested the resistance of the stator (15 ohms to ground, .03 ohms threw stator coils) im now in the understanding the stator is toast, how would you go about testing the regulator without the bike running?

An the ECU is toast becouse of black marks on the board and 0 ohms resistance between the kill switch wire and the ground wire.Unless this is normal.
Katalyst881
 
Posts: 5
Joined: Thu Aug 24, 2017 2:42 am

Re: Vt250 87 (New Zealand Market) Major Electrical Problem

Postby John Hilmer » Fri Aug 25, 2017 6:00 am

Page 16-6 shows the tests for the R/R.

Note that you won't have the specified meter so the values you measure won't be identical to what is shown. Still, if they are, or not, way off you can be confident that it is or isn't fried.

John
Lord help me to be the man my Labrador thought I was.
It's never too late to have a happy childhood ...
John Hilmer
Moderator
 
Posts: 1979
Joined: Tue Jun 05, 2012 7:29 am
Location: Scotts Valley, Ca.


Return to Electrical

Who is online

Users browsing this forum: No registered users and 1 guest