Topic: Starts with accel pump priming and shortly after with WOT, then dies

[juntjoo]

Later plan on checking my plugs after attempting to start w/out accel pump to check other circuits.

If dry would that probably mean carbs need a good soak?

Which circuit(s) is most responsible for providing fuel at idle? Idle and secondary? I believe I have main, secondary and idle, no more. Anyway...

If plugs are dry, before taking carbs off(PITA requires clumsy painful ratchet strap method) any tips on cleaning from above and/or underneath while mounted? Maybe you guys know some tricks.

Should I try putting the carb spray bottle under the idle screws(removed), cut the straw to fit and spray from under there like that? Sounds like a good idea no?

Or is there something else more probably going on here I should check out. I guess it's been a good six months since I last rode it. While I'm here, for future reference, before you let your carbs sit for too long can you spray them with something or run something through them via the gas to prepare for long rest periods?

Thanks!

[tlbranth]

I didn't understand most of what you wrote but......if the bike runs, put 1/2 bottle injector cleaner in full tank and run it. Do it again.
For long term storage, put an appropriate amount of Stabil Marine in the tank, let it circulate, run it into the carbs then shut off petcock & leave it running 'til the engine stops

[kerryb]

What he said, and...
1. Be careful with modern carb spray cleaner, lt can destroy the rubber parts in your carb.  I had to buy new rubber parts to learn that!
2.  Are you having trouble getting your bike to star?, run?,  idle?.
Have you checked  for spark?,  are your accelerator nozzles clean?  Do you have the stock air box parts in place?

I have struggled with an '82 cb650sc,  you need to have the stock airbox on it...trust me. It would start ok, but not idle or run at low rpm because it had PODS on it.  Lost the pods, problems solved.

If your carbs have sat long enough  to dry out, you may need to pull them and clean them.  Please get a proper gallon of berryman's carb cleaner and follow the instructions.  Don't screw around with pine sol and home brews, use carb cleaner, your carbs will love you for it.

[Scott S]

Do you have the stock air box parts in place?

I have struggled with an '82 cb650sc,  you need to have the stock airbox on it...trust me. It would start ok, but not idle or run at low rpm because it had PODS on it.  Lost the pods, problems solved.

 I wasn't going to bring it up, but since you have the carbs off, now is the time to get the proper air box and intake manifold rubbers and put the air box back on. Get rid of that hokey hose set up you're using to run those dual pods.

[juntjoo]

Do you have the stock air box parts in place?

I have struggled with an '82 cb650sc,  you need to have the stock airbox on it...trust me. It would start ok, but not idle or run at low rpm because it had PODS on it.  Lost the pods, problems solved.

 I wasn't going to bring it up, but since you have the carbs off, now is the time to get the proper air box and intake manifold rubbers and put the air box back on. Get rid of that hokey hose set up you're using to run those dual pods.

Well do you need to have something on the back of them just to get the bike started? I didn't before.

[kerryb]

"What we have here, is a failure to communicate!"  Maybe a picture of the setup you are trying to use is required to make up for a lack of words to provide a proper description of the actual setup. 

For example:  "Do you need to have something on the back of THEM just to get the bike started?
Them?  What is "them"?   Carbs, pods. Intake rubbers, what them?

In my experience, the bike would start and run when cold, but would not continue to run long enough to get home without ALL the stock air intake parts installed.  As Mark Paris carefully describes, it is something to do with the overall atmospheric and vacuum conditions that create the right air/fuel mixture to run properly.

I feel your frustration and I'm trying to help, but there are too many factors involved to use abbreviated information.  Show us where you are presently and we'll take it from there.

[jgger]

Welcome to juntjoo world! He will eventually catch on, he always does. You have to be patient and basic with any solutions you suggest, he just has a little trouble with.................

...oh look there's a butterfly.

No offense Ben👍

[kerryb]

Hey!  I resemble that remark! 

[juntjoo]

"What we have here, is a failure to communicate!"  Maybe a picture of the setup you are trying to use is required to make up for a lack of words to provide a proper description of the actual setup. 

For example:  "Do you need to have something on the back of THEM just to get the bike started?
Them?  What is "them"?   Carbs, pods. Intake rubbers, what them?

In my experience, the bike would start and run when cold, but would not continue to run long enough to get home without ALL the stock air intake parts installed.  As Mark Paris carefully describes, it is something to do with the overall atmospheric and vacuum conditions that create the right air/fuel mixture to run properly.

I feel your frustration and I'm trying to help, but there are too many factors involved to use abbreviated information.  Show us where you are presently and we'll take it from there.

Sorry. I try to keep things short as I tend to make them long plus I don't always know what crucial info is needed.

The title explains a lot though, but not that there is nothing behind the carbs, no pods, no air box. But I don't think that matters. I ran the bike reliably with pods and no pods or air box. Right now I just wanna get it going and even crappy but it's not going. And I think it's the carbs.

Haven't done much since starting this thread except squirt carb cleaner in those flat head screw holes right where the throttle plates are trying to get in the little holes I'm pretty sure would be clogged at this point that are responsible for idle speed operation. But in a moment I'm going to check the plugs as I think that would be a good start right? Verify that I'm getting fuel. Did already but I was using the accel pump to get it to do something.

Thoughts? I'll be back...

Hey, I wish I knew my carbs better. Anyone know where I can get some diagrams/cutout pics of these bad boys? I was googling and found some interesting stuff on the other types. I thi k you call them "pd". Mine are the vb44ca or I think you call em "cv".

And my finger screw idle jets, fuel, not air I believe, up at the front under the throttle, does the circuit go straight up into the throttle body/should I be able to push a wire straight up? IDTS. Wish I could. Oh, I'll go back and clean out my slow/secondary jets. That's easy with carbs on. I got two in mine, main and slow, other tube down there is plugged.

Thanks

[juntjoo]

They are wet. Unless they're supposed to be dripping. This was right after turning the engine over for about 4 seconds with maybe two pops of combustion. Again, if I use the accel pump I can get it to yell and then for a bit more with WOT.

Should I clean the plugs then test again?

Could I be getting fuel but not enough(carbs dirty?)

Is there a way to test spark quantitatively. I'm guessing not. Never heard anything for that. Would rather take out the guess work

Gonna clean out both main jets with carbs on...

[kerryb]

Lets star here,

https://www.cmsnl.com/honda-cb650sc-nighthawk-1982-c-usa_model475/partslist/E++1801.html#.XfaPp-FOlJ9

Edit:  i can't get the link to post properly. (Crapola) you will need to go to   www.cmsnl.com and navigate to 1982 honda cb650sc carburetor exploded view parts fiche....I tried!

Its a link to the cmsnl website showing carbs from an '82 cb650sc.  It shows #19,  a part called a jet, main; that is sized at #118.
Also shown is #20, the slow jet (sometimes referred to as the idle jet )  from your description in the title, it starts when the accelerator pump is used to put fuel in the carbs, but won't run when relying on fuel supplied by the slow jet.  So I'm making the wild assumption that the SLOW jets may be plugged.  My advice is pull the jets (slow) and clean them, which may entail soaking in carb cleaner and pushing a piece of copper wire ( one strand from a piece of normal lamp cord) through to make sure its clean.  You can not do this effectively without taking the jet out of the carb!

And lastly, this brings us to #5, screw set A,  these parts are the air/fuel adjustment screw with a little alumin "flag" glued to the top of it.  These are preset at the factory, the little flag prevents you from turning it more than about 7/8 of one turn.  Leave these alone for now...if they MUST be turned more than that, you can remove the flag by melting the glue with some judicious heat from a propane torch and pull the flag straight off.

When you finish all that, and reassemble the carbs and stock intake plumbing, see if it will start and stay running.  I went through that same procedure and the bike ran and rode well for many miles.  The pods are serving nicely as a light fixture with led bulbs in them!

Last question,  how far have you actually ridden this bike so far, you said it runs "okay" , but the distance or time ridden will give me a clearer idea of the definition of ok.

all part of the adventure...

[juntjoo]

Lets star here,

https://www.cmsnl.com/honda-cb650sc-nighthawk-1982-c-usa_model475/partslist/E++1801.html#.XfaPp-FOlJ9

Edit:  i can't get the link to post properly. (Crapola) you will need to go to   www.cmsnl.com and navigate to 1982 honda cb650sc carburetor exploded view parts fiche....I tried!

Its a link to the cmsnl website showing carbs from an '82 cb650sc.  It shows #19,  a part called a jet, main; that is sized at #118.
Also shown is #20, the slow jet (sometimes referred to as the idle jet )  from your description in the title, it starts when the accelerator pump is used to put fuel in the carbs, but won't run when relying on fuel supplied by the slow jet.  So I'm making the wild assumption that the SLOW jets may be plugged.  My advice is pull the jets (slow) and clean them, which may entail soaking in carb cleaner and pushing a piece of copper wire ( one strand from a piece of normal lamp cord) through to make sure its clean.  You can not do this effectively without taking the jet out of the carb!

And lastly, this brings us to #5, screw set A,  these parts are the air/fuel adjustment screw with a little alumin "flag" glued to the top of it.  These are preset at the factory, the little flag prevents you from turning it more than about 7/8 of one turn.  Leave these alone for now...if they MUST be turned more than that, you can remove the flag by melting the glue with some judicious heat from a propane torch and pull the flag straight off.

When you finish all that, and reassemble the carbs and stock intake plumbing, see if it will start and stay running.  I went through that same procedure and the bike ran and rode well for many miles.  The pods are serving nicely as a light fixture with led bulbs in them!

Last question,  how far have you actually ridden this bike so far, you said it runs "okay" , but the distance or time ridden will give me a clearer idea of the definition of ok.

all part of the adventure...

Thanks. I've seen and bookmarked these "fiche" 's but I was hoping to see like a cutout view or more in depth  diagram of these carbs if one exists., so you can see all the circuits and where they go and which can be accessed with carbs mounted. Looks like you can get to where you need to mostly.

I've already cut those fuel idle jet limiter ears off so I can take them out, but idk if you can shove a wire straight through the circuit into the throat or if you'd need to soak the carb to do that circuit. I'm wondering the same for the slow and main jets, which I can take out easy enough while on bike. Behind the brass jets does it go straight up or start winding around up there? I did actually take these apart and do a complete cleaning but that was over a year ago.

Are we guessing one needs to put the air box on to get it to start cuz as I mentioned I've ridden the bike fine for a months with pods which actually were connected by flexible tubing which kinda simulated an air box but I also ran it fine for about a month with nothing but some masking tape on each carb to restrict airflow. Only problem I had was needing carb spray on cold starts. But I can't even get it started now.

And of course I rode it with the exhaust pipes but I'm pretty sure I've been able to get it running with them off in my garage. Do I NEED to put those on at this point or would it just be a good idea?

I understand the whole stock setup thing with these bikes but I'm not worried about it being perfect right now, just running even crappy and my exp so far says it can run fine with nothing unless someone will insist I need to put on the stock air box on to solve this current problem but I just don't see how that could be the problem now.

I'll clean the slows and report back. Thanks Kerry!

[Scott S]

 Start with putting the exhaust on.

 Get 4 new plugs.

 Pull and clean the carbs with spray cleaner. If they were cleaned and it was running a couple of months ago, you **should** be able to get them clean enough with spray cleaner.

 Buy new intake rubbers and new rubber velocity stacks and put the air box back on.

 You did adjust the valves, right?

[kerryb]

Yes, the mixture screw pathway is straight up into the carb throat, no turns.

[juntjoo]

Almost there. This was after soaking the small jets. Very dirty they were.

So it bogs with throttle then dies but idles a decent bit now. What does that mean? Too lean? Still too dirty in there to let through enough fuel? Am I right? That can't be right tho cuz main jets are clear and go straight up to the throat under that sliding needle. Maybe THAT part isn't working? Nah.. I'm thinking idle fuel circuit is still clogged and I open the throttle I'm getting too much air and insufficient fuel from idle circuit to assist. And from slow jet/circuit too. That doesn't go straight up through either does it? It winds through the carb body right?

More than taking the proper steps to remedy this I wanna know how this thing works so I can ask fewer questions in the future. Educate me pls.

I don't think the fuel idle jets go straight up to the throat. I couldn't poke through there. Nor through the slow jet hole/space/seat where the jet screws in.

B4 I go taking the carbs off and apart, if I can get it to ride if only horribly up and down my street could I run something through it with the fuel like sea foam for a while? Haven't I read in here you guys doing that or suggesting it or are my carbs too dirty?

Going to sleep now but just put some straight sea foam in the throat through those ports covered by the little flat head screws, where in #3 the vent tubes used to route. Hopefully it will unclog a bit more by morning. I'm hoping to get to the point I can just ride it with sea foam( or "redline?) til it's clean.

Gotta get it running by tue so if no luck by evening then I'll just take em out and apart and do the whole 9

[juntjoo]

Yes, the mixture screw pathway is straight up into the carb throat, no turns.

Yeah? For sure? I couldn't get through. We do have the same carbs it appears. I'm using a tiny wire, small enough to go through the slow jet. Maybe I hit hard sediment. Since you're there, can you go straight up into the throat from the slow jet?

[juntjoo]

Start with putting the exhaust on.

 Get 4 new plugs.

 Pull and clean the carbs with spray cleaner. If they were cleaned and it was running a couple of months ago, you **should** be able to get them clean enough with spray cleaner.

 Buy new intake rubbers and new rubber velocity stacks and put the air box back on.

 You did adjust the valves, right?

Yes, valves done. But tbh, every time I check them they are off despite torqing them to spec. I'm thinking I should go beyond the book spec(9-12lb/si) to 15. I shall get plugs since if they don't make a dif I'll just hold onto them til later. I may need to take carbs out judging by the filth found on my slow jets. See the mess of my above post. Trying to understand the anatomy and function of these carbs. One day I may put that dang air box back on. One day.

[Scott S]

 Put the exhaust on. See what happens when you have some back pressure.

[kerryb]

Yes, the mixture screw pathway is straight up into the carb throat, no turns.

Yeah? For sure? I couldn't get through. We do have the same carbs it appears. I'm using a tiny wire, small enough to go through the slow jet. Maybe I hit hard sediment. Since you're there, can you go straight up into the throat from the slow jet?

If you actually pull the carbs off the bike, you can easily remove the jets (they screw in and out), and spray a cleaner through the passages to find out where they go.  The slow (idle) jet passage enters the throttle bore next to the mixture screw outlet.  The downside of doing it this way is that your passages may get cleaner, you will see the atomizer holes in the jets, and your neck won't get so sore trying to work upside down.  The tiny little holes in the jets are so hard to hit with those tiny little wires that I would be surprised if anyone could clean them effectively while still on the bike...just sayin'

On another note, as has been said many times before, these carbs are set up to run clean (lean) for emissions purposes.  So if you are trying to start and run without your homemade intake restrictors (pods with masking tape) there won't be enough pressure differential to pull the fuel up through the jets and into the carbs. 

[juntjoo]

Got her going. Thanks for all your help. Took off carbs and found a couple of the slow jet circuits took a while to get the spray cleaner through from the float side. This was educational. You gotta take them off to turn them upside down to get gravity to pull cleaner through those circuits through to the throat. Other stuff can be reached with carbs on, unless you've got a worse situation. Mine was minor. 6 months sitting caused this. I guess next time I plan on not riding it for a while I'll empty the bowls and run some cleaner through the system to save me a future carb cleaning.

Future tip/lesson learned: it's way easier to get the carbs back on with the boots on the carbs 1st rather than them on the head 1st. No ratchet straps needed this time.

[juntjoo]

I didn't understand most of what you wrote but......if the bike runs, put 1/2 bottle injector cleaner in full tank and run it. Do it again.
For long term storage, put an appropriate amount of Stabil Marine in the tank, let it circulate, run it into the carbs then shut off petcock & leave it running 'til the engine stops

Thanks. I'll make a note of that for future reference.

[kerryb]

 Congrats,  you should be proud of your accomplishment.

[juntjoo]

Congrats,  you should be proud of your accomplishment.

Thanks! I am! It's not that easy for me to do much. Not the most accomplished person and I've got some mental and physical issues and not a lot of money so I gotta flex through little challenges like these and I rarely do things 100% right, I had a 3.2 GPA at most in community college lol, so these moments feel great. But much thanks to those that help along the way like you guys so hats off to you for generously contributing your knowledge/experience in here for me.

Yeah, I'm really happy I decided to get my first bike at 41. I'm a bit of a minimalist and like to work on my own stuff and cars/trucks are a little tougher to work on and cost more. I only had a feeling I'd enjoy a bike, but little did I know how much I love it.