Starter keeps dying

Hi all,

I have a 1984 VF750F and have been doing more work on it than I care to be doing. The starter died on the way home from purchasing the bike. Since then I have put in two rebuilt starters. Both worked for some time, but eventually die. I've had the bike for about 6 months, and haven't rode it more than 200 miles. Any ideas on what might be causing this would be appreciated. Starter relay? Starter solenoid? Please also let me know how to test what you might think would be wrong with it. Thanks in advance!

 

What are the symptoms of the dying starter?

 

It is quite unexpected. Most times the bike will start up, but now and then, the bike won't start no matter how long you try and start it. The starter will begin to weaken so I'll stop trying. Come back later and it might start fine over and over. In addition, I have a problem with the idle. I have the idle adjusted correctly, but the throttle acts like its stuck open, (3000-4000rpm) even though all the throttle are closed as well as choke. Any ideas?

 

First, I hope you are not just holding the starter button for a long time. It can burn up the starter. I don't hold it longer than 5 seconds before giving it about 30 seconds rest to cool down.

I don't think the starter solenoid is the issue.

A well-tuned, daily used bike should start as soon as you touch the starter button. If only used on weekends, it may take 2-3 tries.

The idle being stuck at 3-4K rpm could be an air leak or badly synced carbs.

To test for an air leak, spray WD-40 around the carb boots (all 4) and see if the idle changes. If it does, you have an air leak. Tighten the clamps or get new boots (new boots most likely fix).

If no air leak, get your carbs synced.

 

I've been reading around some other threads and have begun to think that it is probably the regulator rectifier that is at fault. Carbs got cleaned and inspected, throttle lubed and working fine, no air leaks, good new starter and good battery. Relay seems to be working fine, switch fine. Things that are wrong include the high idle, more common as it gets warmer, turn signals will cut out, bike won't hold an idle in street traffic, won't start while hot, must let it cool down. R/R perhaps? If so should I just replace?

 

Test the RR per the book. Think you may have two issues. Electrical and bad carb sync...

(are your brass choke valves all the way seated when the choke is "off"? If you can push them in even a little bit, they need to be cleaned)

 

It sounds like more than one issue. The high idle sounds like the carbs were not cleaned thoroughly or correctly leaving you with a partially restricted idle circuit. The idle then gets turned up for cold running conditions then as the bike warms up, the idle comes up as well. Second, the hot re-start. If you can get the Honda maual it has a test for the "purge control valve" which will cause the problem you describe. I got bit by this in a shop years ago and never will forget it. Ths Honda manual will walk you through the test. It's not hard at all. Best of luck to you.

 

On a First Generation?

If so, ya' learn something new everyday...

 

You can look up the parts on a site such as Bikebandit.com or any other. I did an eleven year stretch at Honda dealerships and I did see some stuff back then. It was news to me too the first time.

 

Hey, thanks for all your help guys. I decided to replace the Regulator / Rectifier unit for about $20 on ebay and it has solved some of the problems. The bike seems to have no trouble starting under any conditions, the idle has returned to normal, the blinkers no longer cut in and out. These are only results after 3 fairly short rides though. And also, I have noticed the idle will hang a little higher as the r/r heats up, so I'm going to mount a computer case fan to it in order to cool it down.