Horrible GRINDING noise when starting my 1982 CM250C

[dylan.hedden]

--I am new to this forum, please let me know if I should post this somewhere else--

often (almost every time), when I start my Honda CM250C there is an awful metal on metal grinding noise that I think is coming from either the crankcase or the starter motor. The engine also is not catching (ie its not running). I pulled the starter motor out and opened up the crankcase. The gears/chains do not seemed to be worn out. The starter motor brushes are not worn down. I have read that the noise could indicate that the starter motor is not getting enough juice from the electrical system/solenoid (the battery is brand-new). Can anyone verify this? Any other suggestions/ideas what it could be?

Thanks!

[Easy Rider 2]

Originally Posted by dylan.hedden

(the battery is brand-new). Can anyone verify this? Any other suggestions/ideas what it could be?

As always, you should start with the easy stuff first.

Was the new battery fully charged BEFORE installation ?? If not, you should do that now.

Was it doing that before you changed the battery ??

Then you should check the connections at both ends of the main battery cables for tightness and corrosion.

If all that checks out I'd do a simple voltage test on the solenoid just to be sure but it's likely that you have a problem with the "starter clutch". Since I'm not sure what kind of clutch arrangement there is, someone else can take over at that point.

I suspect that a shop would charge you less than $100 to diagnose the problem.

[dylan.hedden]

Originally Posted by Easy Rider 2

As always, you should start with the easy stuff first.

Was the new battery fully charged BEFORE installation ?? If not, you should do that now.

Was it doing that before you changed the battery ??

Then you should check the connections at both ends of the main battery cables for tightness and corrosion.

If all that checks out I'd do a simple voltage test on the solenoid just to be sure but it's likely that you have a problem with the "starter clutch". Since I'm not sure what kind of clutch arrangement there is, someone else can take over at that point.

I suspect that a shop would charge you less than $100 to diagnose the problem.

Thanks for your comments. Just to follow up on some of your initial questions.

The battery was fully charged and it was doing it before I replaced the battery. I was planning on calling the shop today or tomorrow, but I thought I would see what people thought on here first.

I'll work through this list of suggestions and report back. Thanks!

/DHN

[The Spaceman]

You didn't say anything about the condition of the starter gear or the gear it engages. It sounds to me like they're worn and not fully meshing. Or the solenoid is weak and not fully engaging the gears.

[dylan.hedden]

Originally Posted by The Spaceman

You didn't say anything about the condition of the starter gear or the gear it engages. It sounds to me like they're worn and not fully meshing. Or the solenoid is weak and not fully engaging the gears.

Forgive my ignorance, I am new to this (in fact, I bought this bike as a way to learn more about engines and mechanical systems)...Is the starter gear the same as the starter clutch? If so, I have not had a chance to look at it yet. I need to get a freewheel puller. Does anyone know what kind I need, or how to find out?

As far as testing the solenoid, at what reading from the voltage meeter will I know that the solenoid is bad or not?

[seruzawa]

You remove the hot wire from the starter and place the +lead from the meter on it. You put the -lead on the engine case near the starter. When the solenoid operates you should see the full battery voltage across the hot lead. However this is a poor test because a defective solenoid could send enough current to make the meter read but not enough current to activate the starter motor properly. The meter only requires a few milliamps but the starter requires several amps. The internal contacts in the solenoid can burn over time which reduces their current carrying capacity while you can still read the full voltage at the solenoid output.

[dylan.hedden]

Originally Posted by seruzawa

You remove the hot wire from the starter and place the +lead from the meter on it. You put the -lead on the engine case near the starter. When the solenoid operates you should see the full battery voltage across the hot lead. However this is a poor test because a defective solenoid could send enough current to make the meter read but not enough current to activate the starter motor properly. The meter only requires a few milliamps but the starter requires several amps. The internal contacts in the solenoid can burn over time which reduces their current carrying capacity while you can still read the full voltage at the solenoid output.

Thank you for the good advice. Is this the standard/only test? Does anyone have a test that is better at determining whether the solenoid has enough current to make the starter motor properly engage?