Topic: Bad sounds while not firing on all cylinders?

[mono]

Hi All,

So about a week ago I was going for a short ride on my 550 when it started running on less than 4 cylinders.  I was limping it home when it suddenly made a bad sound and jolted -- i thought I had run over a piece of sheet metal in the road.  Then it did it again one more time before I got home (the 2nd time I realized it was the engine causing the commotion).

Got home, turned it off, pulled the plugs - #3 was fouled with gas.  adjusted points, and once it cooled off a bit i tensioned the cam chain and pulled the valve caps to see if anything was damaged --- looks OK -- no weirdness anywhere, no dinged caps, no oil leaks... so I fired it back up and all seemed OK.  have put about 50 more miles on it since then with no apparent side effects, but now I'm paranoid.

any ideas as to what could have caused the ruckus and if there's anything I should check on?

[dave500]

forcing them to run on less than four always makes them act #$%*ty.,dont worry about it,and dont force it to run when it wants to stop.

[deafcaferacer]

forcing them to run on less than four always makes them act #$%*ty.,dont worry about it,and dont force it to run when it wants to stop.

I had the same issue today.. as much as it makes sense to pull over and deal with it right there, oftentimes that's not the smartest thing to do, and often you have to go home on less than 4. I guess the key is to avoid sudden acceleration or pushing the engine, e.g., going too fast? I stayed at consistent speed in medium rpm in low gears til I got home.

[flybox1]

I had a funky idle since Sunday evening, so no riding.
yesterday i had time to work on it, and i found that my #3 plug cap (all caps are 3 months new) likes to back itself off the plug for no reason. 
push it on, and click-click-click it wants to back off.  wtf!?!    nothing in the plug hole blocking it from seating on the plug.
plug comes out, looks fine, cap off and back on the coil wire, back in and now it stays on and i'm back on the road.
IDK what that was all about.   

so, check that your plug caps are on all the way and secure.

[mono]

forcing them to run on less than four always makes them act #$%*ty.,dont worry about it,and dont force it to run when it wants to stop.

I had the same issue today.. as much as it makes sense to pull over and deal with it right there, oftentimes that's not the smartest thing to do, and often you have to go home on less than 4. I guess the key is to avoid sudden acceleration or pushing the engine, e.g., going too fast? I stayed at consistent speed in medium rpm in low gears til I got home.

both times it happened i was limping it at around 3K RPMs in 2nd -- probably going 15MPH at that point on a side street -- not sure if it was during acceleration or not, but i had to half-throttle it to keep it going.  it sounded/felt like it fired suddenly and caused the cam to stop.  but again, no weird noises, no leaks... i guess i'm just worried that something got bent and I don't want any bad surprises down the road (literally!)

-- as long as

[mono]

I had a funky idle since Sunday evening, so no riding.
yesterday i had time to work on it, and i found that my #3 plug cap (all caps are 3 months new) likes to back itself off the plug for no reason. 
push it on, and click-click-click it wants to back off.  wtf!?!    nothing in the plug hole blocking it from seating on the plug.
plug comes out, looks fine, cap off and back on the coil wire, back in and now it stays on and i'm back on the road.
IDK what that was all about.   

so, check that your plug caps are on all the way and secure.

oh, they stay on good, but that's good advice thanks

[BobbyR]

Do you have electronic ignition? If it is an electric problem likde a plug cap coming off, usually 2 cylinders will go out either 1-4 or 2-3.

[Fritz]

Once, while I was riding in heavy rain on the autobahn at about 95mph, #4 stopped running. I just went on with about 75mph until I reached the next exit. It was just a matter of pulling the spark plug cap and pour out the water that had gotten into it
I did not hear any strange noise from the motor. Running on three cylinders is not really bad I think. On lower RPMs maybe...

[mono]

Do you have electronic ignition? If it is an electric problem likde a plug cap coming off, usually 2 cylinders will go out either 1-4 or 2-3.

No, I'm on points.  It really felt like 2 cylinders, but i didn't check the pipes for heat.

I am planning to order a Hondaman ignition as soon as i have the cash.  in the meantime I'm going to clean and re-sync my carbs.  I didn't do it last season but it ran quite well until recently.

[BobbyR]

Do you have electronic ignition? If it is an electric problem likde a plug cap coming off, usually 2 cylinders will go out either 1-4 or 2-3.

No, I'm on points.  It really felt like 2 cylinders, but i didn't check the pipes for heat.

I am planning to order a Hondaman ignition as soon as i have the cash.  in the meantime I'm going to clean and re-sync my carbs.  I didn't do it last season but it ran quite well until recently.

Cleaning carbs is always a good thing to do. I had something like what you are describing.  If it is intermittent, pipe heat is not a great diagnostic tool.

Mine acted up in a decent spot to pull over, all I needed to do is reach down pull a plug wire, and when it stayed the same. I knew I had ignition problem.

There was a post here in which he had a faulty plug and it allowed the circuit through the engine block to fire the opposite plug and not the other.
 

[mono]

So here's a new symptom: I cleaned and adjusted the points then fired it up yesterday and noticed that it was running really smoothly.  so I took it out for a ride.  after about 3 miles it started getting  choppy again, intermittently and only at low RPM, and I might have been imagining it, but I *think* i heard a spark arcing when i pulled it into my driveway and right before I turned it off..  will have to check using the "pull the plug while running" method.

BUT if this is a "once it's warmed up" related issue, could it be that a coil is going bad?  it really felt like it was just missing a spark every now and again.

AFTER WARMING UP:
- was idling OK (a little waver on the tach, going from 1200-1300 RPMs randomly)
- sputtering at takeoff, but once i cleared about 1600 RPMs it pulled hard, but then flattened out at 5K RPMs (abnormal)
- felt like it was missing a little immediately after upshifting.

I realize this all seems symptomatic of a clogged idle jet too.  cleaning carbs tonight.  in the meantime, pretend my carbs are 100% OK and toss any ideas about electrical problems my way

Thanks guys! 

[dave500]

got a multimeter?check the plug caps resistance.

[mono]

have spark on all 4 plugs -- think im going to replace my condensers and points, since they are of unknown age.

anyone know if the points that are sold through partsnmore.com are any good?  says they're OEM, and they have good prices and what looks like a honda number -- scroll down a bit:

http://www.partsnmore.com/parts/honda/cb550/?filters[fitting]=custom&filters[category]=electrical

[bjbuchanan]

For what it is worth to you I used a set of Daichi points, made in japan, not china and they are working just fine on my bike. I got the tuneup kit from dime city and that is what came in it. I was able to easily time at static .014 after my other assorted issues were taken care of

[dave500]

have spark on all 4 plugs -- think im going to replace my condensers and points, since they are of unknown age.

anyone know if the points that are sold through partsnmore.com are any good?  says they're OEM, and they have good prices and what looks like a honda number -- scroll down a bit:

http://www.partsnmore.com/parts/honda/cb550/?filters[fitting]=custom&filters[category]=electrical

if your points and condensors are of unknown age so are the caps unless youve replaced them?the caps as they age increase resistance even on low milage bikes,bad caps left in place with other new parts installed will trip you up everytime,and will end up being the last thing you check and or replace,they are cheap,even though you have spark through uncompressed air bad caps will give a feeble spark once under load.

[mono]

thanks, Dave - that's a good point too.   i went and picked up a multimeter last night at Harbor Freight, so I'm going to give it a good going through tonight to try and locate a problem as opposed to just throwing money at it (although I'm still replacing the condensers and points).