Author Topic: What Did I Do To Make It Not Start?  (Read 2788 times)

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Offline Chachi

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What Did I Do To Make It Not Start?
« on: November 09, 2011, 11:41:22 AM »
I am new to this and I am very appreciative of all of the advice and answers I have received so far. That said, please give me some help on this one... Things were running fairly smoothly, but now I can't get it to turn over and if I can it won't last. The only thing that (I know) I did from when it was running this morning to now not running now is 'adjust' my carb intake boots. I say 'adjust' because I did not remove them, but I had been noticing that two of the boots were not fully seated in their respective airbox openings. I got them to seat properly by pushing in the bit that was out with a screwdriver tip. Yes, the boots are old and fragile and I will eventually replace them, but the intent and approach was a simple tidying up a bit until replacement. The only other thing I might've done was left the ignition switch 'on' (not key). I simply can not remember, but I had been out working on some things a few hours prior.

The best way I can describe what is happening now is that it doesn't seem to be getting fuel. I was able to get it to turn over with full choke and sometimes if I change fuel supply to reserve. Electric starter starting sounding like it was giving out, so I let it sit and was able to crank it some and get it going and I can then do it as well with electric start. BUT, no matter how long I hold throttle to warm up... it will die.

What did i do?
73 CB750 K3
72 CB500 K1 - Sold
75 MR50 Elsinore K1

Offline Chachi

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Re: What Did I Do To Make It Not Start?
« Reply #1 on: November 09, 2011, 11:50:06 AM »
To clarify: when I said 'carb intake boots' I am referring to airbox to carb:
http://www.davidsilverspares.co.uk/CB500K1-FOUR-1972/part_61399/
73 CB750 K3
72 CB500 K1 - Sold
75 MR50 Elsinore K1

Offline dave500

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Re: What Did I Do To Make It Not Start?
« Reply #2 on: November 09, 2011, 11:52:08 AM »
on the fuel tap remove the filter and have a look?

Offline luap

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Re: What Did I Do To Make It Not Start?
« Reply #3 on: November 09, 2011, 11:54:58 AM »
weak electric start sounds like a dead battery, give it a charge or a jump, tanks are gravity fed try filling up the tank completely check your fuel lines
paul
75-550 ffsc sold, 78-550 diamonte sold, 125s grasshopper sold, 76-550 puma sold, 78-550 tracker sold, 74-550 verde diablo Sold, 74-550 Noemani finished trying to sell. 72 500 hartail in the works
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"I dont need a bike covered in paint an chrome I know exactally bout how big my coc( is"

Offline Chachi

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Re: What Did I Do To Make It Not Start?
« Reply #4 on: November 09, 2011, 12:22:51 PM »
Dave... on petcock fuel bowl?

luap... I have a friend bringing over a charger to rule that out, but I can kick it and get it to turn over, but only on full choke and again, it doesn't last. Can the kill switch affect battery even with key off?

I have inline fuel filters and they seem to be flowing ok. Could making the minor adjustments to two of the airbox to carb boots have done this?
73 CB750 K3
72 CB500 K1 - Sold
75 MR50 Elsinore K1

Offline bjatwood

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Re: What Did I Do To Make It Not Start?
« Reply #5 on: November 09, 2011, 12:31:30 PM »
Petcock bowl is the correct verbage Dave is talking about. And after it starts, take it off full choke immediately. These bikes have no fast idle circut on them and they need some air after initial light up. What you did to it should NOT make it not run. I'm thinking your battery is toast (not fully charged) this will have a major effect on how things run. Let us know how things go with "Joanie" the bike. LOL
Brian
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Offline Chachi

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Re: What Did I Do To Make It Not Start?
« Reply #6 on: November 09, 2011, 12:38:11 PM »
I did recently add a petcock fuel bowl screen which was not there when I got the bike (two weeks ago). I have ridden since then and have had no issues.

So to belabor this as I am waiting on my battery charger... can the kill switch left on with key off affect battery charge? I am still not 100% sure if I even did that, but it is possible.
73 CB750 K3
72 CB500 K1 - Sold
75 MR50 Elsinore K1

Offline bjatwood

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Re: What Did I Do To Make It Not Start?
« Reply #7 on: November 09, 2011, 12:39:39 PM »
can the kill switch left on with key off affect battery charge? I am still not 100% sure if I even did that, but it is possible.

The key in the OFF position should kill all the circuts.
Brian
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I believe that the Finest things are the most thoughtfully made, not the most expensive!
http://minibikers.proboards.com/

Offline Chachi

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Re: What Did I Do To Make It Not Start?
« Reply #8 on: November 09, 2011, 12:44:40 PM »
A lot was happening so there is a chance I might've left key ON. I'll sort that out with my charger and post back.
73 CB750 K3
72 CB500 K1 - Sold
75 MR50 Elsinore K1

Offline Chachi

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Re: What Did I Do To Make It Not Start?
« Reply #9 on: November 09, 2011, 01:20:50 PM »
Petcock fuel bowl looked ok. Charger is here... I was assuming I could just jump it from the charger. What am I missing?
73 CB750 K3
72 CB500 K1 - Sold
75 MR50 Elsinore K1

Offline Chachi

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Re: What Did I Do To Make It Not Start?
« Reply #10 on: November 09, 2011, 02:20:58 PM »
I've got it charging on the 2A setting on my charger (lowest available). I'll update later.
73 CB750 K3
72 CB500 K1 - Sold
75 MR50 Elsinore K1

Offline Gordon

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Re: What Did I Do To Make It Not Start?
« Reply #11 on: November 09, 2011, 03:35:59 PM »
I've got it charging on the 2A setting on my charger (lowest available). I'll update later.

I bet that solves the problem.  Current symptoms combined with the fact that it was running fine just before point to a nearly dead battery.  Or you're almost out of gas.

Offline Chachi

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Re: What Did I Do To Make It Not Start?
« Reply #12 on: November 09, 2011, 06:01:19 PM »
Battery fully charged, but same situation. The battery is only a few weeks old (YAUSA YB12A-A). I can get it to turn over with full choke only, but it will barely last and it's not even coming on that strong. As soon as I open choke, it dies. Seems like a little more action is coming out of the left muffler (including some smoke) vs. right if that detail helps at all.

Ideas?
73 CB750 K3
72 CB500 K1 - Sold
75 MR50 Elsinore K1

Offline luap

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Re: What Did I Do To Make It Not Start?
« Reply #13 on: November 09, 2011, 06:59:16 PM »
so everything worked fine before you refitted the intake bootys did you punch a hole in the bottys when refitting ? how much were they sticking out before you refitted them? small piece of something might have clogged your idle when you were cleaning things up,
maybe try pulling the air box out, might have been sucking more air with the booties not in all theway
75-550 ffsc sold, 78-550 diamonte sold, 125s grasshopper sold, 76-550 puma sold, 78-550 tracker sold, 74-550 verde diablo Sold, 74-550 Noemani finished trying to sell. 72 500 hartail in the works
www.cb-town.com
"I dont need a bike covered in paint an chrome I know exactally bout how big my coc( is"

Offline Chachi

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Re: What Did I Do To Make It Not Start?
« Reply #14 on: November 10, 2011, 04:45:33 AM »
Is the set up of the boots that sensitive? My boots on 2 and 4 had a small section each that was not seated all the way in, but I was able to push them in. I'm going to also check to see if all 4 pipes get warm at start up too. I'm not sure when the carbs were last cleaned, but it did come from a good home (mechanic) and was running well just a few days ago. Feel free to keep passing along any suggestions.
73 CB750 K3
72 CB500 K1 - Sold
75 MR50 Elsinore K1

Offline Chachi

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Re: What Did I Do To Make It Not Start?
« Reply #15 on: November 10, 2011, 08:47:45 AM »
Regardless of anything else previously mentioned, this is the latest:

-Will not start (electric or kick)
-Header pipes:
1 - gets warm
2 - nothing
3 - warm, but not as warm as 1
4 - nothing
-Battery has been fully charged
-Fuel level is ok

Thoughts?
73 CB750 K3
72 CB500 K1 - Sold
75 MR50 Elsinore K1

Offline Chachi

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Re: What Did I Do To Make It Not Start?
« Reply #16 on: November 10, 2011, 08:55:00 AM »
Tried once more and only got warmth on header pipe 3.
73 CB750 K3
72 CB500 K1 - Sold
75 MR50 Elsinore K1

Offline Hondawggie

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Re: What Did I Do To Make It Not Start?
« Reply #17 on: November 10, 2011, 09:32:22 AM »
Tried once more and only got warmth on header pipe 3.
First I would recommend saying 'it turns over' for describing the *attempt* to start it and then say 'it fires up' when the 'turning over' results in an engine start-up (however brief the start up might last).

The engine will 'turn over' all day but 'the engine fires' leaves no confusion when you're asking for advice; just a suggestion -- it was a bit confusing (not a big deal though) but I think you meant above that you are getting her to fire up sometimes, and not simply turning over.

Here's a quick couple things to do so we can better assist you:

1) pull the spark plugs and tell us what each one looks like (is one or more plug wet with fuel? for example), and be careful to keep track of which plug came out of which cylinder so we can advise on what is happening in each cylinder based on its own spark plug.

2) put one spark plug into its spark plug cap and lay the base of the plug so it touches the metal part of the cylinder (so it's getting an electrical ground) and turn the engine over with the key on (just turn it over) and do that one by one for each cylinder.    Then let us know if you saw a spark on each plug.  If any plug did not spark it's important to know that.

3) if you have a volt meter, turn on the bike's key (but don't try to start it) and with the key on measure the voltage across the battery and tell us what you see (note -- make sure the + and - battery leads are hooked up to the battery when you read the voltage on it with the key on -- this is a very simple 'load test' to see how much the battery voltage drops when it's supplying power to the bike's electrical harness and fixtures).

If you do those steps it will really help advising.  My guess is your plugs are fouled.   And maybe the battery under load is a bit low.   The bike will not run well at all if the battery is low.   The symptoms sound like a low battery and fouled plugs (from all the choke use perhaps).

If you charged the battery and then you measured the voltage on it *right after* you took it off the charger, the voltage you read will be artificially high.  Measure the voltage 1 hour after the charger is removed.   You have a dang good battery, a Yuasa, so if you charge it right and clean them plugs you should be good to go.   Those two carb-airbox boots will affect the running but are not a big enough influence to cause your symptoms -- but a low battery and fouled plug(s) are.
« Last Edit: November 10, 2011, 09:36:04 AM by Hondawggie »

Offline Chachi

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Re: What Did I Do To Make It Not Start?
« Reply #18 on: November 10, 2011, 10:11:21 AM »
Thanks for all of the advice.

I was just attempting to pull the plugs to look for wet fuel, however I don't have a proper tool to get them out. Same goes for volt meter (lack of one). I just got the bike, so I don't have everything I need yet.

The last thing I was going to check at the moment is the fuel flow from the tank. I first removed the lines from the inline filters to check for flow and got nothing. Now the tank is off the bike and I'm still getting nothing through the petcock. I'm even tilting the tank front to back to make sure gas is getting back there, etc. Fuel valve is set to open and nothing is coming through the two lines or the hole above fuel bowl screen. Screws holding petcock to tank are stripped.
73 CB750 K3
72 CB500 K1 - Sold
75 MR50 Elsinore K1

Offline Chachi

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Re: What Did I Do To Make It Not Start?
« Reply #19 on: November 10, 2011, 11:13:58 AM »
I added more fuel to the tank and shook the tank around a bit (off bike) and that got fuel flowing again. When this started I did have fuel in my inline filters and in petcock fuel bowl so I thought fuel was flowing properly. I'm not sure if I had some trash in the tank or what that blocked it, but now that I've shaken the tank up fuel is flowing as it should and bike is running well.
73 CB750 K3
72 CB500 K1 - Sold
75 MR50 Elsinore K1

Offline Rgconner

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Re: What Did I Do To Make It Not Start?
« Reply #20 on: November 10, 2011, 11:23:15 AM »
You sure your not just out of gas?

Is the petcock in the primary or reserve position.

Sounds like you had it on primary, and adding gas got it high enough to flow.

Primary leaves 1.5 gallons or so in the tank, which looks like a lot because of the shape of the tank.
1975 CB550K aka "Grease Monkey"

Offline Chachi

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Re: What Did I Do To Make It Not Start?
« Reply #21 on: November 10, 2011, 11:30:31 AM »
I could not get gas to flow from primary or reserve. I'm not saying it wasn't perhaps lower than I assumed, but I could not get anything to come out. I added gas before I shook it up a bit, so I don't know really if it was the added gas or shaking that got fuel flowing.
73 CB750 K3
72 CB500 K1 - Sold
75 MR50 Elsinore K1

Offline dave500

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Re: What Did I Do To Make It Not Start?
« Reply #22 on: November 10, 2011, 11:41:57 AM »
might have been both?have you downloaded the manual for it yet?youll need to get a few tools if you want to start any service work on it,starting with the sparkplug socket.

Offline Chachi

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Re: What Did I Do To Make It Not Start?
« Reply #23 on: November 10, 2011, 11:50:13 AM »
I've got original manual! Seller couldn't find it and when I got bike home I realized why: it was in document compartment under seat. I hear you on the tools... I'm making a list.
73 CB750 K3
72 CB500 K1 - Sold
75 MR50 Elsinore K1

Offline Gordon

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Re: What Did I Do To Make It Not Start?
« Reply #24 on: November 10, 2011, 12:17:39 PM »
I've got original manual! Seller couldn't find it and when I got bike home I realized why: it was in document compartment under seat. I hear you on the tools... I'm making a list.

He's talking about a shop manual, not the owner's manual.  You'll need one before you start doing any work on your bike.  They're available for free download in the sticky thread at the top of the sohc4 bikes forum.