CB360 running issues

cahurst2001

Been Around the Block
So I have some running issues. It starts, but won't stay running. I do have issues getting it started, too, but not as severe. After 5-8 kicks, it will begin to fire and eventually start up. Then I have to rev it a bit to keep it going which produces some white smoke. It idles at about 1800-2000 roughly for a minute or two. If I remove the choke it revs to 3500-4000 and dies. If I give it throttle, it will die.

I have checked the plugs and they were black which makes me think it is just really rich, but my idle screw is only a full turn out. I'm running straight pipes and pod filters, so it wouldn't be in too much danger of running lean. Also, once it dies, it can take ten or more kicks to fire up again, if at all. I figured it was just because it is so rich that it needs time to drain.

Do I need to just reclean the carbs, set the floats, and what not or is it just a carb tuning issue? Do I need to let it warm up longer? I can't say for sure if the carbs are synced, is that it?
 
Ok, lets start with the basics here.

First, you have a pipe and pods on it. If those carbs havent been rejetted, you're going to be lean. No matter what anyone else says. MOST of these bikes came from the factory LEAN to begin with. The pods and pipe will compound the situation. So, I would guess that unless you know for a fact those carbs have been up-jetted, this is a START of your problem.

Second, when you say the plugs are black, and white smoke is coming out the pipe, Id start thinking you are burning oil, which means the rings and valve guide seals may need some attention/replacement. Check your plugs again. BLACK and FLUFFY is too much fuel, BLACK and SMOOTH or SHINEY, is oil. Rough to think about, but if this is the case, its time to pull the head and jugs. If its NOT oil, another thing i would be investigating is your valve clearances. I dunno the specs on the Hondas anymore, but this is a VERY often overlooked issue on old bikes. The hard cold starting that you're talking about is a symptom of poor valve clearances. Also, Check your intake manifold boots for air leak, this will add to lean running issues, and is another often overlooked issue. BTW, untill you are sure your valve clearances are in order, I wouldnt even bother with the carbs, as things are going to change once the valves are adjusted to spec. If im not mistaken, and again, its been a good while since ive seen the top end of a Honda motor, but most of the SOHC hondas used a tapped adjuster screw rather than a shim over bucket or under bucket tapped design. Which makes adjusting the valves MUCH easier for you, *I* have to replace shims on my 8v Suzuki GS motors. Check those plugs out, see what you think, sounds like you may have your work cut out for you to me. Good luck! :)
 
The plugs are what I would call fluffy, not shiney by any stretch. The smoke is sparse, and that was only when I gave it some pretty good throttle.

I haven't rejetted because I thought there were a few guys on here w/360s running pods and straights, like chrisf, that didn't have to rejet.
 
Well, the bike won't even start now. Probably 30+ kicks and troubleshooting w/no start. After cleaning the plugs thoroughly and spraying some carb cleaner in the carbs, it sputtered but didn't start.

If I'm running lean with the pods and pipes, should I just completely close the idle screws and see if it starts?
 
cahurst2001 said:
Well, the bike won't even start now. Probably 30+ kicks and troubleshooting w/no start. After cleaning the plugs thoroughly and spraying some carb cleaner in the carbs, it sputtered but didn't start.

If I'm running lean with the pods and pipes, should I just completely close the idle screws and see if it starts?

Have you looked at your points? I had some issues, but I changed the points and this helped tons.
 
Druro said:
Have you looked at your points? I had some issues, but I changed the points and this helped tons.

Yeah, the points are ok. Brand new when I bought the bike 6 months ago. I cleaned them and checked the gaps on em. I have a strong spark and the wires all have good connections.
 
Soooo I let the bike sit overnight. Turn the idle screws to the richest setting (all the way in), two kicks and it runs. Let it idle at 1800 for about a min/two w/no problems. It starts to surge to near 3-4k and dips to about 1500 intermittently. I take the choke off a little and it dies, then I can't get it started again after 10 kicks. I pull the plugs and the right one has a little black fluff on it and the left has none except a bit on the electrode.

I'm open to any and all suggestions.
 
Have you done a compression check?


When you kick and kick and it doesnt start, check the plugs. Are they wet with gas? Or dry? Wet would mean, no spark, bad timing or something. If dry, then you're not getting fuel to the engine.
 
Re: CB360 running issues (now w/pics!)

Ok, so I got the bike running, but it won't stay that way.

I let it sit overnight and, in typical fashion, today it starts after 2 kicks. It runs kinda rough and hovers around 1600 RPM with the occasional jump to 3k. I don't touch it for several minutes and it doesn't die. Long enough to get the header wrap to smoke. If I take the choke off it revs really high and dies, if I give it throttle, same thing. Eventually it dies on it's own.

This is the longest it has ever run, so I pulled the plugs and got this:

2801188716_9df719f943_b.jpg


My camera won't focus that close b/c it's pretty old. I posted the large one to give a better clue.

2801188422_8226914fbc.jpg


I know black means rich, but black can also mean oil. They were 'wet' per se right when I pulled them out, but after 5 mins (second pic) they were 'dry'. Didn't smell like oil, but I doubt a gas/oil mixture would be smellable. I wouldn't think it would be running that rich w/pods and pipes, but what do I know?

Am I totally screwed?
 
Have you got an inline fuel filter installed on your bike. If not install one and consider puliing your carbs down and giving them a good cleaning. Dirt in the fuel on a bike that has not run in a long time is not uncommon. If it gets into the carbs it is a pain in the ass. While you have the carbs off for cleaning, follow through with some of the previous suggestions like inspecting your carb boots and checking the valve adjustment, and the float levels making sure they still float. When setting the idle mixture screw, adjust it 1 to 1.5 turns richer than the recommended setting. Do an initial carb sync using a small drill bit to equalize the carb opening.

Hopefully, after all that , the bike will idle where you can set your timing , tweak your idle mixture, and do a running carb sync. Then, it is off to pilot and main jetting. As mentioned earlier, you are certainly going to be buying bigger main jets. As far as the pilot jets go I haven't had to replace those on a piped and podded bike yet however I have never messed with a cb 360 either. Hopefully some guys on the board that are running these bikes can give you some starting points so that you can drop something in while the carbs are apart.

Tuning a new combination is a lesson in frustration when things don't work and joy when you make a breakthrough. Stick with it and that bike will run great!
 
cbcafe said:
Have you got an inline fuel filter installed on your bike. If not install one and consider puliing your carbs down and giving them a good cleaning. Dirt in the fuel on a bike that has not run in a long time is not uncommon. If it gets into the carbs it is a pain in the ass. While you have the carbs off for cleaning, follow through with some of the previous suggestions like inspecting your carb boots and checking the valve adjustment, and the float levels making sure they still float. When setting the idle mixture screw, adjust it 1 to 1.5 turns richer than the recommended setting. Do an initial carb sync using a small drill bit to equalize the carb opening.

Hopefully, after all that , the bike will idle where you can set your timing , tweak your idle mixture, and do a running carb sync. Then, it is off to pilot and main jetting. As mentioned earlier, you are certainly going to be buying bigger main jets. As far as the pilot jets go I haven't had to replace those on a piped and podded bike yet however I have never messed with a cb 360 either. Hopefully some guys on the board that are running these bikes can give you some starting points so that you can drop something in while the carbs are apart.

Have new inline fuel filters and have been working before and after carb cleaning.
Carb boots are ok, floats work and are set to manual specs. Haven't checked the valves, but that's such a pita, unless there is some easy way I don't know of.

How do I do a carb sync with a drill bit?

The idle screws are all the way in now. They were 1.5 turns out, but bike wouldn't start.

There are a couple guys, chrisf and mysta2 for example, who didn't change their jets on their 360s.

Where is a good place to get jets?
 
Honda 350s and 360s tend to like a fully charged battery. I know this because I've had the exact same problems with my 350 and a friend's 360 just last week. You may see spark, but it might not be as strong as you think, which would explain the black plugs.

Try this, it's really easy and takes 2 minutes:
1) disconnect your battery completely
2) hook up jumper cables from the bike's positive and negative leads to your car battery like you're jump-starting another car
3) kick her over and see if there's a difference

It's worked for me twice ;)
 
I know with my Triumph I you run straight pipe and pod filters you need to rejet both mains and pilots. I can't see why your bike would be any different. More air in more air out... You need more fuel. I think that is why when you turn the idle screws in you can get it to run. just my $0.02
 
Is this legit? as in would this blow up your battery?

milwaukeephil said:
Honda 350s and 360s tend to like a fully charged battery. I know this because I've had the exact same problems with my 350 and a friend's 360 just last week. You may see spark, but it might not be as strong as you think, which would explain the black plugs.

Try this, it's really easy and takes 2 minutes:
1) disconnect your battery completely
2) hook up jumper cables from the bike's positive and negative leads to your car battery like you're jump-starting another car
3) kick her over and see if there's a difference

It's worked for me twice ;)
 
You know, as far as jetting is concerned, I spent about 6 weeks ignoring the advice of the experienced older guys to forget about jetting up and concentrating on my tuning. After having the carbs off about 15 times, and thinking I had the jetting "right" before it failing miserably, again, I found the correct combination "stock", well, 70, 105, (and I'm running pods and short pipes)....
 
Fuel Mixture Screw (from scratch)

I pulled everything off the carbs then put back only only OEM and fresh parts, for fuel mixture do I close it completely then back out One and a Half turns? Thats a number Ive heard a few times regarding going from nothing.

I discovered I need to dress my solenoid actuator last night, hence having no starter button untill I arc the leads with a philips head.

And although I now understand that, I HAVE LOST SPARK TO MY PLUGS... ahhh.. The only reason I could imagine why is because I gapped my points and have yet to test their accuracy with a timing light, BUT that doesn't mean their should be no spark at all... I'm going to go probe it with a voltmeter until something makes sense...

But if you know what typically causes no spark on a previously sparking lead, say so.
 

Attachments

  • truck.jpg
    truck.jpg
    60.4 KB · Views: 220
I guess the amount of posts on CB 350/360 carbs shows it isn't as simple as people think to be a motorcycle technician ::)
You have multiple issues with bike, need to fix one thing at a time.
First, check battery voltage with ignition ON needs to be more than 10.5v, if it's dropping, battery is shot.
Check points actually open and close at correct time, just setting gap isn't good enough.
No spark after re-setting them means you probably did it in wrong place, you have gasket on points cover?
Points can short out without it
Carb screws all the way in is MAXIMUM LEAN not rich, it's a fuel screw not air screw.
Pods and short pipes suck on 360'syou will not get carburation right although you may get it rideable if your prepared to put up with way less than optimal performance
 
kewl, so I have mild air filters, and may need to start with the mixture screws quite a bit out, and equally so. The battery is new but needs charge, which by now it should be (over night). I think (know) its a matter of the point timing. (*see chapter 3 of the manual for tuning ;D)
 
Back
Top Bottom