1990 1000F. Went for a ride stopped to look at bike for sale on the side of the road. When I went to restart, it turned over real slow, almost not starting. I went home and pulled the batery and charged it. Started great. Went for a short 5-10 ride to test it. Stopped along side of the road and tried the restart thing. Same thing, real slow turn over.Went homelet it cool for a hour or so and tried starting it again and it started fine. Anyone have a good idea where I should start-battery? starter? Hope it is just a battery problem.

 

Was it a warm day ? - sounds like fuel vapourisation.

 

Yes it was warm but the motor turned over slowly, like the battery was dead. I don't think it is a gas issue.

 

I would start by checking all of the earth connections between battery and frame and especially between rectifier pack and frame.
( Check the positive connections too )

I would also put an extra earth cable between the battery and the rectifier pack earthing point.( favorite fault on the 1k )

 

It sounds as the charging system may have failed. A bad battery can initially have caused this. Since it started after manual charging but didn't start after some driving, I assume it is a charging problem.

Put a voltmeter across the battery terminals and measure the voltage when the bike is turned off. It should read about 12.5 volts. Then start the engine and measure the voltage at a few thousand rpm, it should be about 14 volts.

If you start with this you can then be further guided. In short, the next step if the charging is faulty, will be to check whether it is the generator or the R/R unit.

As other has mentioned, also check that connections are OK.

 

Started her up today, turned overslightly slower than a full charged battery but fired right up.???I had not charged the battery. Only seems to have the problem when the bike is at riding temp. I'll check my con. and the volts. If it is a gen. is it hard to do or expensive? Man I hope this turns out to be the battery!

 

Or it can just be that you have been driving at low revs in hot climateand the cooling fan etc has drained the battery. It is normal that a battery that is not fully charged (or bad)can be dead when hot but still provide current to start when let to cool down, so what yourecognize at hot temperarures is a sign of a not fully loaded battery.

A part that is not uncommon to fail on CBR 1000 F, and other Hondas,is the R/R unit (rectifier/regulator). Start to measure the voltages and report yor findings.

 

Ok I think I did it correct. I have not used this meter much! Anyway I get 12 while the bike is not running and 11.60 when it is. Bad news huh? All connections look good. Where is the r/r? Hard to replace? Expensive? How about the gen.? Thanks for all the help w/this problem!

 

OK, next step would thento be to check if it is the R/R or the alternator that has failed. The R/R is located on the rear frame under the rear plastic. See link to service manual below.

Disconnect the plug from the generator that goes into the R/R unit. Start the bike and measure the AC voltage in the harness plug, yes it is alternating current on this side, and measure the voltage between the three yellow wires. The voltage at about 5 krpm shall be about 50 VAC. Measure between yellow 1 and 2, then between yellow 1 and 3 and finally between yellow 2 and 3. They should all be about the same, i.e. 40 to 60 volts AC.

In case the voltages between the yellow pairs are OK, it is the R/R unit that is faulty. It is quite easy to replace.

If you download the service manual on http://www.members.iinet.net.au/~cbr...ice_Manual.pdf you can also see what resistance valuesthere should be in the altarnator wirings and the R/R unit. The manual is provided by another member, Trips,on this forum.


[IMG]local://upfiles/4562/2B15838AACBF49CD895C05FD504D179C.jpg[/IMG]

 

I'd look to the battery first. Try a test ride near home. If your charging system is bad the bike will eventually die while riding, if the battery is bad it won't. If you can ride the bike 30-45 minutes without her shutting down, you're probably charging ok, but your battery is shot. If she dies while riding, then look to the regulator/rectifier or the alternator. Needless to say, don't go too far from home on the ride. and if she starts to feel funny on the ride, head straight home.