Author Topic: bike not starting after short ride (Read 2336 times)

Sitarz84 · « **on:** August 10, 2012, 04:39:01 AM »

I took my 77 CB750 out for a ten minute ride yesterday. I was making sure my tire alignment was good after adjusting
my drive chain. I think it was. Anyways after the ride I simply pulled into my garage and turned it off. I then remembered I wanted to let it run in idle for a little bit to adjust my idle speed, so I went to turn it on and it seemed like it wanted to turn over but it wouldnt. I'd hear a couple attempts, (not sure what to call it) then it would die down and the lights would bog down with it. If I let it sit for a few hours it seems like it comes close to starting up but the end result it the same. The bike bogs down and lights go with it. Maybe I need gas, I have no fuel indication but that doesnt seem likely. I'm going to fill it up today but I seriously doubt thats the problem.
Any ideas?

LesterPiglet · « **Reply #1 on:** August 10, 2012, 04:45:37 AM »

Charge your battery.

Sitarz84 · « **Reply #2 on:** August 10, 2012, 04:57:48 AM »

Really? When I turn on the ignition switch the lights come on no problem. When I let go of the start button the lights come back on. I wouldn't think it was a battery issue. What would make you think its a battery issue, and I'm not asking because I think you're wrong, I'm asking because I don't know a lot about bikes and I really want to learn. So far I'm really enjoying the process.
I will absolutely give that a shot though.

thanks for the help

harisuluv · « **Reply #3 on:** August 10, 2012, 05:09:22 AM »

From what you described. After awhile you will be able to tell how charged your battery is just by how fast or the sound of the starter motor turning over the engine.

Sitarz84 · « **Reply #4 on:** August 10, 2012, 05:50:07 AM »

Would a battery lose its charge after a ride?

harisuluv · « **Reply #5 on:** August 10, 2012, 05:55:30 AM »

There are different variables. Charge, used to start (does it start up right away or does it have to crank for awhile), how long was the ride (a short ride might not be long enough to recharge the starter motor), is the bike generating AND/OR charging the battery optimally in the first place, how long has the bike been sitting? (the battery will drain slowly even though nothing is "on."

ChuckG750f1 · « **Reply #6 on:** August 10, 2012, 06:04:49 AM »

Quote from: LesterPiglet on August 10, 2012, 04:45:37 AM

Charge your battery.

Time to get out your multi-meter.

trueblue · « **Reply #7 on:** August 10, 2012, 06:12:12 AM »

Sounds to me that the battery is weak, it has enough power to run the low current loads, like lights etc, but as soon as you place a large load on it, the voltage drops to a point where it is useless. A lead acid battery will 'recover' slightly once you remove the load from it, hence why when you leave it for a while it comes goodish. Try charging your battery, if that doesn't work you may need a new battery. Oh and don't forget it takes more effort which equals more current to turn over a warm engine than a cold one, because when warm all the tolerances are tightened up and the engine produces more compression.

Sitarz84 · « **Reply #8 on:** August 10, 2012, 06:23:31 AM »

Ok

Quote from: trueblue on August 10, 2012, 06:12:12 AM

Sounds to me that the battery is weak, it has enough power to run the low current loads, like lights etc, but as soon as you place a large load on it, the voltage drops to a point where it is useless. A lead acid battery will 'recover' slightly once you remove the load from it, hence why when you leave it for a while it comes goodish. Try charging your battery, if that doesn't work you may need a new battery. Oh and don't forget it takes more effort which equals more current to turn over a warm engine than a cold one, because when warm all the tolerances are tightened up and the engine produces more compression.

I didn't realize it would take more current to start up on a warm engine. I have not had to battery on a charger in at least 3 weeks. I'll bust out the voltmeter and see what I'm getting. It also makes sense that I would need to go on a longer ride to get the battery charged again. Awesome advice.

trueblue · « **Reply #9 on:** August 10, 2012, 06:43:06 AM »

If you want my advice, throw the old lead acid and get an AGM battery. I put one in my 650 and it has never been on a charger in over a year, it still fires up strong everytime and it can sit for a month and all I do is go out turn on the fuel and key, hit the button and away it goes, none of this trickle charger BS some guys go through. The amount of current it takes to swing a warm engine isn't that much higher than a cold engine, on these small engines, but if the battery is weak from a long wind when initially started 10 minutes ago, remembering that it will take a lot more than 10mins to bring the battery back up to charge, then the extra bit it takes to swing the hot engine may just be too much for the battery to handle. If the battery is fine then check all your electrical connections paying particular attention to the earths.

flybox1 · « **Reply #10 on:** August 10, 2012, 06:47:01 AM »

Quote from: ChuckG750f1 on August 10, 2012, 06:04:49 AM

Quote from: LesterPiglet on August 10, 2012, 04:45:37 AM
Charge your battery.
Time to get out your multi-meter.

This ^ and clean your harness

Sitarz84 · « **Reply #11 on:** August 10, 2012, 07:25:50 AM »

Quote from: trueblue on August 10, 2012, 06:43:06 AM

If you want my advice, throw the old lead acid and get an AGM battery. I put one in my 650 and it has never been on a charger in over a year, it still fires up strong everytime and it can sit for a month and all I do is go out turn on the fuel and key, hit the button and away it goes, none of this trickle charger BS some guys go through. The amount of current it takes to swing a warm engine isn't that much higher than a cold engine, on these small engines, but if the battery is weak from a long wind when initially started 10 minutes ago, remembering that it will take a lot more than 10mins to bring the battery back up to charge, then the extra bit it takes to swing the hot engine may just be too much for the battery to handle. If the battery is fine then check all your electrical connections paying particular attention to the earths.

I'll look into that battery. So looking at the "earths" haha. I would take all my ground connections and ohm them to my negative on the battery and hope for a nice .01 reading right?

ChuckG750f1 · « **Reply #12 on:** August 10, 2012, 07:46:50 AM »

What voltage does the battery have???

Sitarz84 · « **Reply #13 on:** August 10, 2012, 08:18:49 AM »

Quote from: ChuckG750f1 on August 10, 2012, 07:46:50 AM

What voltage does the battery have???

12VDC

Spanner 1 · « **Reply #14 on:** August 10, 2012, 08:24:35 AM »

No... actually measure the battery voltage por favor... I know it says 12v on the side of the batt....
Start the bike and place the red meter lead on the + battery terminal and the black lead on the - term. and rev the bike to 3,000 , 4,000 and 5, 000 rpm and report what voltages you get . Be sure the meter is set to 'DC Volts' at the 50 or 100 v setting....

Sitarz84 · « **Reply #15 on:** August 10, 2012, 08:44:25 AM »

Quote from: Spanner 1 on August 10, 2012, 08:24:35 AM

No... actually measure the battery voltage por favor... I know it says 12v on the side of the batt....
Start the bike and place the red meter lead on the + battery terminal and the black lead on the - term. and rev the bike to 3,000 , 4,000 and 5, 000 rpm and report what voltages you get . Be sure the meter is set to 'DC Volts' at the 50 or 100 v setting....

I was being kind of a smart ass with the 12VDC comment.
Thats a good idea to test the voltage with the high RPMs. I never would have thought of that. What kind of reading should I hope to get? I would imagine that I would want to have it stay at 12V.
When I check the voltage and the battery is fully charged without the bike running is a little over 12. Like 12.3 or .4

ChuckG750f1 · « **Reply #16 on:** August 10, 2012, 10:22:52 AM »

You should see in the area of 14V DC when you rev up.

Sitarz84 · « **Reply #17 on:** August 10, 2012, 11:10:55 AM »

10-4 I'll give that a try today after work.

thank you sir

HonderCB · « **Reply #18 on:** August 10, 2012, 03:44:30 PM »

the charging system in your bike doesnt kick in at low rpms, so if your battery was already somewhat low, and you never got your rpms up in your short ride, you might have drained your battery, or it is possible that your charging system isnt working properly.

Your best bet will be to charge the battery and then run diagnostics from that point as everyone else has stated. cleaning terminals and connections never hurts.

Sitarz84 · « **Reply #19 on:** August 13, 2012, 04:45:01 AM »

it was as simple as the bike not being charged enough. I charged it up this weekend and everything started up fine.
I took it out on some backroads and opened it up a bit. I had no problems at all.

harisuluv · « **Reply #20 on:** August 13, 2012, 06:00:33 AM »

Yay problem solved.

Sniper X · « **Reply #21 on:** August 13, 2012, 02:57:21 PM »

Always ride vintage bikes with he headlight off except at night or unless you feel the NEED to have it on. I even suggest buying a cheap but bright small LED flashlight and use it as a city light during the day instead of the headlight to be seen. I use a super bright LED flashlight as a driving light on my 73 CB350F for really dark back roads. It is like 420 lumens so WAY brighter then the headlight even on high, and will last 8 hrs on a set of six AA batteries. I use rechargeable batts in it and keep an extra set in the tool kit ready to go. This saved my butt on a ride when my headlight blew out on a different bike and I got home from 120 miles away!

liPPy · « **Reply #22 on:** August 13, 2012, 04:10:11 PM »

?

Quote from: Sniper X on August 13, 2012, 02:57:21 PM

Always ride vintage bikes with he headlight off except at night or unless you feel the NEED to have it on. I even suggest buying a cheap but bright small LED flashlight and use it as a city light during the day instead of the headlight to be seen. I use a super bright LED flashlight as a driving light on my 73 CB350F for really dark back roads. It is like 420 lumens so WAY brighter then the headlight even on high, and will last 8 hrs on a set of six AA batteries. I use rechargeable batts in it and keep an extra set in the tool kit ready to go. This saved my butt on a ride when my headlight blew out on a different bike and I got home from 120 miles away!

Illegal in Illinois.

Spanner 1 · « **Reply #23 on:** August 13, 2012, 04:21:27 PM »

I bet the problem is not fix'd

.... the OP only went for a short ride with a battery that had been ( externally ) charged..... pity he didn't bother to measure the charging voltage ( if any

).....

News:

Author Topic: bike not starting after short ride (Read 2336 times)