The Big Four-Oh

[mf70]

Lovely fall day today, so I rolled out, coasted down the hill a few feet, and bump started. After a spirited few miles, I was at the store. Stopped, shopped, and got back on. No crank. Hmmm. No ignition light either, and, come to think of it, I'd used the horn on the way, and it had sounded anemic. I had put it down to not having been operated for years, but it might have been weak battery... However, the bike had had started fine a day earlier.

Fuse? No, looked good.

Jump the solenoid. Silence.

Opened up the battery compartment. Oops, I had put one of the MotoBatt AGM batteries in four years before, and it came with cool low profile hex socket machine screws instead of good old hex cap screws. I didn't have any allen keys in the tool kit. (Nor a voltmeter). Fortunately, the "wiggle the terminal as you twist the screw" trick worked, and I could pull the battery. Daid flat dead. Not even a spark between the terminals.

Sigh.

Fortunately, the store's parking lot had a slight grade, and Suzi fired right up on a bump start, so I got home without dealing with a tow company. I don't even know what I would have looked for if I'd needed one..

Lessons? AGM isn't magic. They're warranted for two years, and a voltage test or two over the last couple of years might have given me some warning. It sure did seem sudden and total, though.

Next time I'm out, I'll have the tools to pull the battery, as well as a voltmeter. Sigh. Still, for a 1979 machine, she's holding up her end pretty well.

[Redman]

Good that you made it home.

Still need to determine if:
- battery failed
or
- charging system failed
or
- was it loose connection at battery (maybe, since you could get apart with fingers)

Having a volt meter will help in that, rather than buying a new battery.

[salty_monk]

I haven't had that experience with the MotoBatt - you can usually tell when they are on their way out like you can with most any AGM battery.. Glad you got home.

AMA membership is about $50 annual and includes tow package (works on your car too...)

[Rob S.]

My first question is: why did you bump start in the morning? Looking at your signature tells me you weren't being courteous to neighbors as it's not a big bore four.

You must have known something was up.

[OldVet66]

I had something similar happen a little while ago that prompted me to get a volt meter. Went up to the store and when I was ready to go home the battery was flat. Had to go in and get a set of jumper cables and get a jump to get home. Motobatt battery that has never frozen. Got back to the house checked the terminals, all were tight. Put it on my battery tender, was fully charged the next morning. The only explanation I have is short drives in the city draws the battery down at lights faster than the battery can be charged in city traffic. Ordered a volt meter, battery always reads in the 13V range before startup and charging kicks in at lower than expected RPM's. I guess I will just have to get out of the city more for extended rides at speed.

[mf70]

Thanks all for the feedback!

I've had a LOT of experience with flat batteries in the old days (before I discovered this forum) due to (what I learned once I'd joined the forum was) a blown R&R as well as blown alternator. Up till now the MotoBat was been wonderful. That may be where I got into the bump-start habit.

salty_monk, thanks for the AMA tip. Since the battery is four years old, I've gone ahead and ordered a new one (MotoBat). I NOW have a voltmeter and allen key the correct size for the battery terminals with me. I'm thinking of mounting a small voltmeter in the cluster somehow.

redman, you're right about still needing to figure out what happened. Yeah, the first thing I thought of was a loose connection, but I didn't find any. The fact that I couldn't even get a spark between the terminals is just weird. Charging (see below) seems to be OK.

I habitually bump start at the beginning of a ride because:

• it's easy.
• It is quieter.
• It will turn over the engine long enough to bring good gas into the carb if it's been a month "off duty."
• The "choke" doesn't seem as effective if it's cold.
• I worry about wear on the starter & battery capacity.

As far as that time, the terminals were fairly tight, and had no corrosion. As soon as I got home, I pulled the battery. Voltage was ~5V. I put it on a gentle charge. It came up to voltage fine, and seemed to hold charge a day after being on the charger. To test, I put the headlight on while cranking, and it seemed pretty steady, and started easily. I checked idle voltage, and it seemed healthy (~14). The new battery isn't here yet, but I've made a few trips on the old battery. Things seem OK, but I do keep an eye out for hills in case I need to bump start again.

[Steve]

I found this to be rather interesting.

I habitually bump start at the beginning of a ride because:

• it's easy.
• It is quieter.
• It will turn over the engine long enough to bring good gas into the carb if it's been a month "off duty."
• The "choke" doesn't seem as effective if it's cold.
• I worry about wear on the starter & battery capacity.

Maybe our definitions of "bump starting" are different. My version is pushing the bike to get going fast enough to turn the key ON, put it in gear and pop the clutch to engage the engine. Please tell me how THAT is "easy".

The only way it's "quieter" is that you don't hear the whirring of the electric starter motor. Not a big deal.

Unless you live at the top of a LONG hill, I don't see how you are going to turn the engine over long enough to prime the carbs. Why not just turn the petcock to PRIme, instead?

The "choke" (thanks for putting that in quotes ) is PLENTY effective, but you have to use it properly. They key to using it is to NOT touch the throttle at all. Set the "choke", turn the key ON, pull the clutch lever (unless you have disabled that "safety" feature), push the starter button. Do NOT touch the throttle.

If you worry about the wear on the starter and battery, you must be a LOT younger than me. I am much more worried about the wear and tear on my old body trying to push the bike fast enough to get it started. I have replaced a few batteries and a couple of starters, but let's face it, these bikes are about 40 years old and these are wear items, or normal maintenance items.

By the way, when is the last time you checked your valve clearances? With valves set properly and clean, properly-set carbs, you don't have to do much more than give the starter button a stern look before the engine is running. Not much wear and tear on the battery and starter.

.

[storm 64]

My 850 starts with just a tap of the button. If I'm with other people, I always say "I sure hope this old thing will start" then I tap the starter button and the engine comes to life! Good motorcycle... 👍

[Rob S.]

My 850 starts with just a tap of the button. 

Ditto that for my Suzi, as long as the battery is fully charged. And I make sure it always is. Bump starting a 570 lb motorcycle on level ground without assistance is no fun.

[LAB3]

Another thumbs up for my 450! When my stator went about 10 days ago I was able to bump start it on level ground with a 25 foot run.

[salty_monk]

Haven't used one but these look interesting... https://antigravitybatteries.com/pro...ker-lead-acid/

[mf70]

Steve, on a 10% grade hill where I live, it starts in about 20 feet. And there's no effort in coasting downhill. On the day of the mystery zero-voltage battery, I got a boost from a helpful clerk and the parking lot was slightly downgrade. On cold days (below freezing) and after a month's storage, it can take ~100 feet of run to light. In those conditions, moving the fuel cock to "Prime" would be a good idea!

I installed the voltmeter! It seems that an early version of the instrument cluster had an "ignition" pilot light which had been blanked out by 1979. I excavated the blanking and mounted the tiny voltmeter in the space (Sorry if it's upside down - I don't think vBulletin® Version 4.2.5 likes me):

New-voltmeter.jpg

Watertight, compact, and not an "add on." As voltage source, I tapped into the tach panel light. Since I generally run with lights on, it should give enough data.

Mark

[mf70]

Hmmm, after a short ride and another look at the wiring diagram, I think I'll shift the +12V source to the hot side of the neutral indicator. The neutral switch is on the ground leg, so the hot side will be on all the time the ignition's on.