Author Topic: Motorcycle Starting issue (Read 2137 times)

jetthugo · « **on:** September 16, 2015, 11:56:11 am »

Im new to the riding community so Im still learning terminology and the mechanics of a motorcycle. My newly purchased 1973 Honda CB350F usually runs well, but at times won't turn over as seen in this video. I rode it two days ago for about a good hour but did not attach my trickle charger after parking it in the garage. But would the battery really be low after a day and a half? It's charging right now, but does it sound like something else could be wrong? Thanks for everyones help and solutions.

Here is the link to the video

Mantree · « **Reply #1 on:** September 16, 2015, 12:22:15 pm »

I didn't see you use the choke I'd there a strong gas smell?

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jetthugo · « **Reply #2 on:** September 16, 2015, 12:36:03 pm »

Thanks for replying Mantree. I trimmed the video so it didn't show me messing with the choke on this, but yes I had it open but still no go.

There is an abnormal gas smell coming out of the bike.

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calj737 · « **Reply #3 on:** September 16, 2015, 01:06:15 pm »

That video clip does not indicate a battery problem, but a carb/fuel problem. It may be that you're flooding the engine, or, that you're not getting enough fuel into the carbs. Impossible to say without more diagnosis.

jetthugo · « **Reply #4 on:** September 16, 2015, 01:11:03 pm »

Thanks for the reply calj737. I'll look into these two possibilities. I just rode it no problem two days ago, but since last week it seems to run whenever she wants to.

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Mantree · « **Reply #5 on:** September 16, 2015, 01:22:33 pm »

Might be spark too check plug condition that will give you a good starting point on if you are flooding or to lean. Wet is flooded carbon is weak spark or rich. White is lean golden brown is spot on. Clean or replace plugs and set gap. It is 73 so it has points pull the right side cover and look for scorching then check the connections at the coil as well as condition of the coil.

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jetthugo · « **Reply #6 on:** September 16, 2015, 02:11:40 pm »

Thanks Mantree. I'll check out the spark plugs and get back to you on that later today. Thanks for the tip!

jetthugo · « **Reply #7 on:** September 16, 2015, 05:09:09 pm »

Here is what one of the plugs looks like. The second one looked the same. Replaced them with new ones and the bike still won't start. What do you think the new issue might be? I'm researching and someone said the engine might be running too rich. If this is the case, how do I fix this problem?

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Stev-o · « **Reply #8 on:** September 16, 2015, 06:15:08 pm »

First off, check battery voltage after you fully charge the battery, should be 13+ volts.

Secondly, from the looks of your plug, carbs appear to be set super rich (too much fuel).

When was the last time the carbs were rebuilt? May have wrong size jets.

jetthugo · « **Reply #9 on:** September 16, 2015, 06:42:00 pm »

Thanks for your reply Stev-o. I'll let it charge overnight and get back to you on that battery tomorrow.

I purchased the bike two months ago and I'm completely unaware of the last time the carbs were rebuilt. Is that the same thing as "rejetting the carbs"?

scottly · « **Reply #10 on:** September 16, 2015, 07:08:44 pm »

From the way the battery spins the motor, you don't have a battery problem. Do you have a voltmeter? What kind of charger are you using? You may create a battery problem by leaving the charger on it overnight. That spark-plug is horribly fouled.

scottly · « **Reply #11 on:** September 16, 2015, 07:10:57 pm »

Quote from: jetthugo on September 16, 2015, 05:09:09 pm

Here is what one of the plugs looks like. The second one looked the same.

What do the other two plugs look like?

jetthugo · « **Reply #12 on:** September 16, 2015, 07:11:49 pm »

Thanks for the reply Scottly, I do have a voltmeter. I'll check the volts and get back to you. It's a trickle charger that the seller gave me when I purchased the bike. I'll get back to you on that reading. That second plug from the left looks identical.

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Stev-o · « **Reply #13 on:** September 16, 2015, 07:23:27 pm »

Quote from: jetthugo on September 16, 2015, 06:42:00 pm

Thanks for your reply Stev-o. I'll let it charge overnight and get back to you on that battery tomorrow. I

I purchased the bike two months ago and I'm completely unaware of the last time the carbs were rebuilt. Is that the same thing as "rejetting the carbs"?

No. Rebuilding is basically taking them all apart, cleaning and replacing necessary parts.

This may be the logical next step, then you'll know what you have and rejet if needed.

scottly · « **Reply #14 on:** September 16, 2015, 07:30:02 pm »

Might be as simple as a plugged air filter, or running the bike with the choke fully closed all the time.

jetthugo · « **Reply #15 on:** September 16, 2015, 07:46:24 pm »

Quote from: scottly on September 16, 2015, 07:30:02 pm

Might be as simple as a plugged air filter, or running the bike with the choke fully closed all the time.

I'm hoping it's nothing too big of an issue, I'll take a look at the air filter and get back to you. Thanks for the tip!

scottly · « **Reply #16 on:** September 16, 2015, 07:47:44 pm »

Quote from: jetthugo on September 16, 2015, 07:11:49 pm

Thanks for the reply Scottly, I do have a voltmeter. I'll check the volts and get back to you.
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Mantree · « **Reply #17 on:** September 17, 2015, 03:20:58 pm »

Pull the air filter and check it try starting the bike with the filter out of it starts replace the filter if if that don't fix it you may be jetted wrong

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jetthugo · « **Reply #18 on:** September 17, 2015, 03:25:44 pm »

Quote from: Mantree on September 17, 2015, 03:20:58 pm

Pull the air filter and check it try starting the bike with the filter out of it starts replace the filter if if that don't fix it you may be jetted wrong

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When you say air filter, you mean this one right?

Update: took out the air filter and it looks good. Removed and tried to start the bike, still not starting.

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Mantree · « **Reply #19 on:** September 17, 2015, 06:22:08 pm »

Is there a strong gas smell? Pull your plugs again after trying to start if they are wet check for spark you may have a bad coil or something in your points might be off. I have even seen a loose wire stop a bike dead in its tracks. The coil gets power from the kill switch on the handle bars then gets ground when the points arch to ground as he engine rotates. That filter looks a little dirty can you see light through it clearly?

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scottly · « **Reply #20 on:** September 17, 2015, 09:48:46 pm »

Did you replace all FOUR spark plugs?

Mantree · « **Reply #21 on:** September 17, 2015, 10:00:35 pm »

Quote from: scottly on September 17, 2015, 09:48:46 pm

Did you replace all FOUR spark plugs?

He 350 is a twin it's just the 750 engine cut in half

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jetthugo · « **Reply #22 on:** September 17, 2015, 10:00:41 pm »

Quote from: scottly on September 17, 2015, 09:48:46 pm

Did you replace all FOUR spark plugs?

yea! All four were replaced. I think the issue might be with the ignition points. What do you think? Here's a video of it

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jetthugo · « **Reply #23 on:** September 17, 2015, 10:03:28 pm »

Quote from: Mantree on September 17, 2015, 06:22:08 pm

Is there a strong gas smell? Pull your plugs again after trying to start if they are wet check for spark you may have a bad coil or something in your points might be off. I have even seen a loose wire stop a bike dead in its tracks. The coil gets power from the kill switch on the handle bars then gets ground when the points arch to ground as he engine rotates. That filter looks a little dirty can you see light through it clearly?

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I know I said there was a gas smell in the previous posts, but I haven't smelled any since. The plugs still remain dry after I tried starting the bike. I can't see through the filter clearly, just purchased one online from 4into1.com
Thanks for the tips! I have a feeling something is off with the ignition points...

Mantree · « **Reply #24 on:** September 17, 2015, 11:13:54 pm »

Do you have a timeing light? You can use it to make sure you have spark. Is your petcock flowing Gas there should be a fairly strong smell fter cranking like that as you should be close to flooding it

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jetthugo · « **Reply #25 on:** September 17, 2015, 11:32:15 pm »

Quote from: Mantree on September 17, 2015, 11:13:54 pm

Do you have a timeing light? You can use it to make sure you have spark. Is your petcock flowing Gas there should be a fairly strong smell fter cranking like that as you should be close to flooding it

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I just purchased a timing light today, unfortunately I have no clue where to connect it! Been looking to see how to use it. As for the gas, I'll pay extra attention tomorrow when I fire it up. Ill get back to you on that. Thanks Mantree

jetthugo · « **Reply #26 on:** September 17, 2015, 11:40:23 pm »

Quote from: jetthugo on September 17, 2015, 11:32:15 pm

Quote from: Mantree on September 17, 2015, 11:13:54 pm
Do you have a timeing light? You can use it to make sure you have spark. Is your petcock flowing Gas there should be a fairly strong smell fter cranking like that as you should be close to flooding it

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I just purchased a timing light today, unfortunately I have no clue where to connect it! Been looking to see how to use it. What I'm looking at is that red=postitive and black=negative to the battery, then the larger clip goes on the #1 spark plug wire? As for the gas, I'll pay extra attention tomorrow when I fire it up. Ill get back to you on that. Thanks Mantree

Mantree · « **Reply #27 on:** September 18, 2015, 12:35:12 am »

That big clamp goes on the #1 plug wire there is a arrow on it that should be pointing towards the plug then he 2 clips go to battery. There are indexing marks on the points asembaly one on the rotating part and then some on the plate behind mark them with a sliver sharpie this will be good when you set your timing latter as for fuel the petcock will have a fine mesh in it that gets clogged it is meant to be a filter but I tend to take it out and just run a inline fuel filter

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jetthugo · « **Reply #28 on:** September 18, 2015, 11:56:46 am »

Quote from: Mantree on September 18, 2015, 12:35:12 am

That big clamp goes on the #1 plug wire there is a arrow on it that should be pointing towards the plug then he 2 clips go to battery. There are indexing marks on the points asembaly one on the rotating part and then some on the plate behind mark them with a sliver sharpie this will be good when you set your timing latter as for fuel the petcock will have a fine mesh in it that gets clogged it is meant to be a filter but I tend to take it out and just run a inline fuel filter

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Thanks Mantree, listened to your instructions and got it to work. Prior to using the timing light, I saw that the gaps on the points were opening too wide so I adjusted them according to the manual. After this, the bike started. Then I used the light and this is what it showed

Could the problem have been the gap between the points? I'm afraid there is more to this story...

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Mantree · « **Reply #29 on:** September 18, 2015, 02:16:25 pm »

I can't really see your timing marks in the video are they mostly steady (they always waver a little). Points do wear down over time and will need replaced some day when that day comes a automotive tester is nice but not nessisary
http://m.harborfreight.com/automotive-motorcycle/diagnostics/lcd-automotive-multimeter-with-tachometer-kit-95670.html
I'd say at this point just give it a good tune up look up how to build a cab sync tool to tune your carbs in replace that air filter and do your timeing along with a oil change. The cb family of engines are kinda temperamental but they are very strong and just keep running I have a 750 that reads 30k on the clock but I know that the odometer rolled over and it is still going strong

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jetthugo · « **Reply #30 on:** September 18, 2015, 02:31:03 pm »

Quote from: Mantree on September 18, 2015, 02:16:25 pm

I can't really see your timing marks in the video are they mostly steady (they always waver a little). Points do wear down over time and will need replaced some day when that day comes a automotive tester is nice but not nessisary
http://m.harborfreight.com/automotive-motorcycle/diagnostics/lcd-automotive-multimeter-with-tachometer-kit-95670.html
I'd say at this point just give it a good tune up look up how to build a cab sync tool to tune your carbs in replace that air filter and do your timeing along with a oil change. The cb family of engines are kinda temperamental but they are very strong and just keep running I have a 750 that reads 30k on the clock but I know that the odometer rolled over and it is still going strong

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I just purchased a new set of points and condensers to replace the ones that are on right now. I also purchased a new air filter. Last week I purchased a Carb Synchronizer so I think that'll be the next step. I appreciate all your advice and help.

Stev-o · « **Reply #31 on:** September 18, 2015, 02:46:44 pm »

Sounds good - go ride!

Mantree · « **Reply #32 on:** September 18, 2015, 03:00:48 pm »

Quote from: jetthugo on September 18, 2015, 02:31:03 pm

Quote from: Mantree on September 18, 2015, 02:16:25 pm
I can't really see your timing marks in the video are they mostly steady (they always waver a little). Points do wear down over time and will need replaced some day when that day comes a automotive tester is nice but not nessisary
http://m.harborfreight.com/automotive-motorcycle/diagnostics/lcd-automotive-multimeter-with-tachometer-kit-95670.html
I'd say at this point just give it a good tune up look up how to build a cab sync tool to tune your carbs in replace that air filter and do your timeing along with a oil change. The cb family of engines are kinda temperamental but they are very strong and just keep running I have a 750 that reads 30k on the clock but I know that the odometer rolled over and it is still going strong

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I just purchased a new set of points and condensers to replace the ones that are on right now. I also purchased a new air filter. Last week I purchased a Carb Synchronizer so I think that'll be the next step. I appreciate all your advice and help.

Sounds good always great to see someone new willing to put in the work to keep these classic bikes on the road you have picked up a very rewarding hobby there is nothing like the feeling of being able to say you did all the work on your own

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jetthugo · « **Reply #33 on:** September 21, 2015, 03:53:41 pm »

Alright now we're. Ack to it not starting again. Makes a weird "thumping" sound.

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Stev-o · « **Reply #34 on:** September 21, 2015, 04:29:24 pm »

My bike will not start if given throttle when cold.
Try giving full choke and no throttle till it fires.

jetthugo · « **Reply #35 on:** September 21, 2015, 05:54:16 pm »

Quote from: Stev-o on September 21, 2015, 04:29:24 pm

My bike will not start if given throttle when cold.
Try giving full choke and no throttle till it fires.

Here it is with full choke and no throttle..

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Stev-o · « **Reply #36 on:** September 21, 2015, 06:10:17 pm »

I suggest giving the motor the full 3000 mile tune up as recommended by Honda.
If, for any reason you are not able to do this, find someone who is.

jetthugo · « **Reply #37 on:** September 21, 2015, 06:18:22 pm »

Quote from: Stev-o on September 21, 2015, 06:10:17 pm

I suggest giving the motor the full 3000 mile tune up as recommended by Honda.
If, for any reason you are not able to do this, find someone who is.

So far (today) I did an oil change and I replaced the ignition points and condensers. Just checked the voltage on my battery and it's around 11.5, is that low?

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jetthugo · « **Reply #38 on:** September 22, 2015, 01:36:26 pm »

Battery is fully charged and I checked my coils. They're reading at 6 ohm which I think is normal. Here is where it's at, it just does not want to turn over... maybe my ignition points and timing are off?

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Author Topic: Motorcycle Starting issue (Read 2137 times)