Motorcycle charging problem

[commasense]

I just sold a 1989 Honda PC800 (Pacific Coast) to someone who is now telling me it has a problem with the voltage regulator. I never noticed any problems with it, although I didn’t specifically check the regulator.

He says:

Regulator- it is entirely possible that you would not know there was a problem with the part outright, unless you were keeping tabs on voltage readings. When the regulator fails, it does so slowly by creating more voltage than necessary and slowly the battery begins to lose ability to lose charge. I took several voltage readings at the battery and noticed that the voltage was in the 16v range consistently when in fact the voltage should rarely go over 14.5-15. When I get readings of 16-17v consistently, there seems to be a problem. Unfortunately, for many PC people the regulator problem only surfaces when their battery finally can’t take it anymore and the regulator works itself to non use while killing the battery in the process. Because of the nature of the failure of this part, I am certain you had no idea it was on its way out.

I don’t know enough about motorcycle electrical systems to tell if this is technically correct, or if he may trying to make up an excuse to get out of the $100 final payment he owes.

Anyone with MC electrical experience care to comment?

[Oat1957]

He’s correct.

If the voltage regulator is putting more than 15 volts back to the battery it is over-charging the battery.

Eventually, the battery will fry and not hold a charge. If you replace the battery with a new one without replacing the regulator the same thing will happen.

[Berkut]

The 1989 Pacific Coast is notorious for charging system problems. It was redesigned in 1990, which fixed most of the problems. From the PC800 FAQ:

*Q- What maintenance issues should I be on the lookout for?
A- These problems seem specific ONLY to the '89 model:

Stator-the “alternator” for the '89 PC tends to die before 30K miles. Honda won’t usually admit liability. It costs around $400-500 (including dealer labor) to repair. Some of us do the work ourselves. I bought a rebuilt stator and had it installed at the shop. Saved about $200. It’s still working fine. The Stator and Voltage regulator were re-engineered for the '90 model and there have been few problems since then.

[Turbo_Dog]

Although the buyer may be correct, I’d lean more towards what Berkut posted. The 89 PC’s were notorious for their stators wigging out. You can still find the occasional upgrade kit for them that will take care of the problem. A stator will run about $300, not including a nasty labor charge (huge job on a PC). A regulator will run from 100 to 300 with labor, depending on the shop. At the least, the battery may have just started going to hell, which just recently happened on my 94 PC, at I paid just under $70 for a new one.

If all he owes you is $100, if it were me, I’d let it go. Tell him you didn’t know about it, wouldn’t have known how to know about it, and then sign over the title to him, knocking off the final payment. At most, you’ll be out $20, compared to a couple hundred if he insists that you replace the parts.

[casdave]

Classic sign of a regulAtor on the way out is to check what happnes to the headlight as you rev it.

What should happen is that as revs rise, the light becomes a little brighter but stays at that brilliance as the revs continue to rise.

If the regulator is on the way out, the light will continue to get a little bit brighter all the while the revs go up. The battery tends to stop things getting out of hand in this test.

[CookingWithGas]

This is not a matter of mechanics, it’s a matter of law (although IANAL). You are not required to make him whole with regard to any flaws in the bike if you did not warrant it as being without flaws; private party used vehicle sales are generally assumed to be as is–that is, the seller has no responsibility for post-sale repairs. I don’t know in the case of used vehicles if you are even required to disclose all known flaws.

That is, if you didn’t know the flaw existed, and the buyer even says that he is certain you didn’t, you have no responsibility to fix it. If he agreed to the sale and the title is signed over then he owes you $100, period.