Topic: 2nd testdrive, bike stalls after 15 minutes..

[ieism]

I've rebuild the engine, and added pods and a 4into2 exhaust. Plus a ported head.

The jetting stock for my 550K is
Mains 90
Slow 42
Needle clip 2nd from top

I'm now using
Mains 105
Slow 42
Needle clip 3rd from top

The bike starts easy, but while riding feels like i have the wrong jetting. I did a plugchop at WOT and is was lean.
I wanted to drive it to a dyno yesterday, but the bike kept dying after 15 minutes of riding. If I let it stand for 20/30 minutes it starts back up again.
The coils are not overheating, it still has spark when it stalls.
The plugs do not look wet either.

Any tips so I can drive this thing to a Dyno soon?

[Grumpol]

Check your tank vent, if its blocked the vacuum will stall the bike

[ieism]

Checked that. It vents, I also get a healthy stream of fuel from the floatbowl overflow tubes when I open the srews on the bowls.

[Grumpol]

Well my only other thought would have been the battery, but you say its got spark, is it a strong spark?
Do a search on stall or something similar, there has to be something in here about this somewhere. I`m still relatively new to these old machines so i`m stumped.

[ieism]

I'm puzzled by this too. My only guess is that it's so rich that it fouls plugs somehow, or so lean that it overheats and somehow causes something to stop working.

I've made a new appointment for a dynorun on the 31st of december, so maybe he can see what's up. Just hope it rides good enough to get it there.

[Roly]

I had a similar problem with my Yamaha XJ550 that turned out to be a faulty Ignitor. It would cut-out & by the time I checked for a spark it was ok & the engine started. I went through a succession of used Ignitors, most of which would either not start, not run well until warm or cut out when hot, until I found one that ran ok. If the Honda 550 has an ignitor or CDI unit may I suggest you check that by substitution,

Roly (CB400f England)

[Grumpol]

I had a similar problem with my Yamaha XJ550 that turned out to be a faulty Ignitor. It would cut-out & by the time I checked for a spark it was ok & the engine started. I went through a succession of used Ignitors, most of which would either not start, not run well until warm or cut out when hot, until I found one that ran ok. If the Honda 550 has an ignitor or CDI unit may I suggest you check that by substitution,

Roly (CB400f England)

Good point, may be you need to replace your condensors, they have been known to become unreliable with heat

[Soos]

What condition are your fuel lines in?
Any in-line filters? the tank filter plugged?

Don't have a 550, so couldn't give you anything but guesses....


l8r

[bwaller]

Is it soooo lean that it is partially seizing and cooling it loosens it up again? I hate to even mention this.

Lean is lean and isn't good.

[HondaMan]

I've rebuild the engine, and added pods and a 4into2 exhaust. Plus a ported head.

The jetting stock for my 550K is
Mains 90
Slow 42
Needle clip 2nd from top

I'm now using
Mains 105
Slow 42
Needle clip 3rd from top

The bike starts easy, but while riding feels like i have the wrong jetting. I did a plugchop at WOT and is was lean.
I wanted to drive it to a dyno yesterday, but the bike kept dying after 15 minutes of riding. If I let it stand for 20/30 minutes it starts back up again.
The coils are not overheating, it still has spark when it stalls.
The plugs do not look wet either.

Any tips so I can drive this thing to a Dyno soon?

Try replacing the condensors, if you're running points. They leak and make for erratic spark timing when hot, if they are old. Bad coils can also exhibit this same sysmptom.

[Soos]

Try replacing the condensors, if you're running points. They leak and make for erratic spark timing when hot, if they are old. Bad coils can also exhibit this same sysmptom.

Have you tested your coils ohm values?


l8r

[ieism]

Try replacing the condensors, if you're running points. They leak and make for erratic spark timing when hot, if they are old. Bad coils can also exhibit this same sysmptom.

It's getting fuel, the filters clear, no inline filter.

I have electronic ignition. I will try replacing the condensor then, I think I have a spare one somewhere. I do get a fat spark, even when the bike doesn't want to restart, I checked that on the road about a minute after it stalled.

I don't know how to check the coils, I have a meter but i'm useless with it. Will the coils be hot when they are the problem?

If I run it so lean that it almost seizes, would I still be able to turn the engine with the kickstarter real easily? Because I can.

[Soos]

I have electronic ignition. I will try replacing the condensor then, I think I have a spare one somewhere. I do get a fat spark, even when the bike doesn't want to restart, I checked that on the road about a minute after it stalled.

If I run it so lean that it almost seizes, would I still be able to turn the engine with the kickstarter real easily? Because I can.

What electronic ignition do you use?
Do any electronic ignitions use condensors?(hondamans ignition unit?)

If you were runnin' so lean things seized, no you shouldn't be able to turn it over with the kicker.(or I would not believe it is possible)



You would do yourself a favor to familiarize yourself with your meter.





l9r

[MRieck]

 Make sure you don't have vacuum leaks. Did you replace the manifold o rings and intake boots/

[ieism]

Oh, right.... The condensors would be the little things on the pointplate, I don't have those. See, i'm no good with electronics

The electronic ignition came off my 550F that ran great, so I think that's not the problem. The brand is Accent.

Good point on the boots. You're thinking when the manifold gets hot, it starts leaking through the boots losing vacuum?

I will have to look for new boots, will make it easier to put the carbs on too. I still have new o_rings somewhere.

[MRieck]

 Did you do an entire engine rebuild, top end rebuild or just freshen up and port the head?
  If the bike ran ok prior to the rebuild I'd think the electronics would be in order especially if you are using an electronic ignition. Seeing how the carbs and manifolds were removed (and not replaced with new pieces) I have wonder about vacuum leaks especially when it gets warmed up. I have seen it before with the bike dying at stop lights etc. It will usually restart but if the leaks are bad it will have to cool down first.

[ieism]

I did a topend rebuild only. The o-rings between the manifold and engine were good. I wanted to replace them, but the new ones didn't look better. I figured if the ring was much thicker than the height of the groove in the manifold it would be fine (it was).

The bike doesn't just stop at low revs, it even stalled once at about 3/4 trottle in 5th gear. The carbboots were old. I heated them up when putting the carbs back on. I put new screw on the bandclamps to make sure I could tighten them properly. But I will get new ones just to be sure.

[Hush]

What did your plugs look like when you had stalled?
I think they will point you in right direction, if your boots leak air in then they will look lean, if they are black or fluffy you have opposite problem and engine is bogging on too much gas.

[ieism]

They looked lean. That's why I don't understand why it won't start up directly after that....a wet or fouled plug would prevent it from running, but a lean condition shouldn't right?

[thrownchain]

You say it "stalls".  Does it just shut down or acts like it's running out of gas??

[ieism]

It just stops suddenly, not like it's running out of gas.

[Deltarider]

It just stops suddenly, not like it's running out of gas.

And when it stops suddenly... is the rest of the electricity still there?
 
The reason I ask. Mine will stop when I ride to long in the city, like if the battery shuts off to protect itself.

[thrownchain]

Go thru all the electrics. Check your connections and grounds. If they are all good, then you have to get into the components. Just because the system came off a running bike doesn't mean something didn't pick now to go south on you. I don't think it would be the coils, I could see losing one side or the other but not both at the same time.  Which leaves the CDI box and the "trigger" sensor. If the trigger checks out resistence wise, then I would suspect the CDI box. It would be good if you had a "good" one that you could put in to check the system. If not call your local dealer and see if they have the tools to check either or both units.  good luck.

Also check battery voltage, we had problems with Boyer systems in British bikes, CDI units are very susceptible to low voltages. Run very well till the voltage starts to drop, then it just dies right out. But that was a progressive loss of performance. Yours still sounds component caused.  

[joeb]

My bike did that on a ride with Sean Condon right in the middle of the the mc carther maze going to the bay bridge ended up being the battery post my negative side had a crack in it.  Check your connections sounds lioke that is where your problem is.   

[ieism]

Fair enough, but I checked the wiring when I build her. Connections are clean, new battery and new batterywires too. I still have power when she stalls, evrything works. Like I said, i have spark too.

The bike needs only a spark, fuel and air to restart, so why suspect a ground connection when I have a fat spark at the plugs? Coils or ignition problem can stop the bike running properly, but if another electrical component failed wouldn't there be synptoms (like no lights, no spark).