Relay-Version: VMS News - V6.0-3 14/03/90 VAX/VMS V5.5; site msus1.msus.edu Path: msus1.msus.edu!umn.edu!news-feed-2.peachnet.edu!emory!ogicse!news.tek.com!tekgen!interceptor!davet Newsgroups: rec.motorcycles Subject: Re: "Alternative engineering" in electrical? Message-ID: <5284@tekgen.bv.tek.com> From: davet@interceptor.cds.tek.com (Dave Tharp CDS) Date: 14 Feb 94 22:59:57 GMT Sender: news@tekgen.bv.tek.com References: <1994Feb10.121115.62796@pro-haven.cts.com> Organization: Tektronix - Colorado Data Systems, Englewood, CO Article-I.D.: tekgen.5284 Lines: 61 In article <1994Feb10.121115.62796@pro-haven.cts.com> shadow@pro-haven.cts.com (Blaine Hufnagle) writes: >Bike in Question - '82 Yamaha Vision > >Problem in Question - Voltage regulator clamping at 13 volts; hence battery > not staying charged; hence bike not starting. :-( > Spec is 14-15 volts. Do not jump to this conclusion based on voltage measurements, especially with a high-impedance digital voltmeter. It is entirely possible that your battery has a shorted cell (or two) and Mr. Aternator, try as he might, cannot raise the voltage above 13, regardless of the amount of current he can put out. REMEMBER: The vast majority of electrical starting difficulties are due to the battery EVEN IF THE BATTERY IS NEW. Batteries are a high-failure item. Get a +-60 amp cheap ammeter from the auto parts store ($13 at the local Checker). Connect it temporarily, but securely, in the ground lead of the battery with big wire. Start the bike (the 60 amp meter is not really sensitive enough, but you can't blow it out with a motorcycle starter, unless the starter is stalled). Start the engine, and watch the meter. It should be around zero (or discharging due to the headlight) at idle, increase to 5 amps or so by about 3500-4000 RPM, and then level out or drop a bit, maybe to 4 amps or so, as the regulator begins to do its job. By this time, the voltage should have increased to about 15. If a cell is shorted, or other bad stuff has happened, the current will continue to increase, but the voltage will not rise. If the regulator is a shunt-type, also use the ammeter to detect exactly when it begins to shunt current, by putting it in the regulator's ground lead. Increase RPM until the ammeter begins to deflect, then measure the voltage. >My inquiry is this: Is it possible to use an automobile-style voltage >regulator on this bike? Highly unlikely. If the bike has a permanent-magnet flywheel alternator (it probably does), it will use a shunt-type regulator, which is not used in the automotive world. If the bike has a wound-field alternator, and uses a series regulator, an automotive regulator would be set for far too much current. >My thoughts are that the "alternator regulators" have rectifiers built into >them, while the "regulators" don't. Nope. Modern car alternators have the regulator built into the housing. Older ones are external. Regulators for generators are mechanical. External regulators for older alternators may be mechanical or solid-state. Personally, I would never use anything electrical that was designed for a Harley. ----------------------------------------------------------------------------- | Dave Tharp | DoD #0751 | "You can't wear out | | davet@interceptor.CDS.TEK.COM | MRA #151 | an Indian Scout, | | '88 K75S '48 Indian Chief | AHRMA #751 | Or its brother the Chief.| | '75 R90S(#151) '72 TR-2B(#751) | AMA #524737 | They're built like rocks | | '65 R50/2/Velorex '57 NSU Max | | to take the knocks, | | 1936 BMW R12 | (Compulsive | It's the Harleys that | | My employer has no idea. | Joiner) | give you grief." | -----------------------------------------------------------------------------