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CB500/550 / CB550 K3 First thoughts - First Ride - Carb Issue?
« on: October 04, 2013, 12:48:05 PM »
Hi all
It seems I have a little problem with my bike.
Please bear with me and I will try to describe exactly what’s happening.
I bought the bike only a couple of weeks ago after a 15 year lay off from 2 wheels.
It’s a 79 CB550K3 that’s had the café treatment, so the airbox has been removed and its running k&n style filters and a 4 into 1 pipe. Tank and seat unit, clip-ons and rear sets complete the look.
I blatantly ignored all questions from my family asking if i would be alright on that "with my back".
On my first available weekend i proudly rolled the bike out of the garage to start it up and listen to the beast.
Petrol - check
Neutral gear - check
Kill button to run - check
Contact!
Several presses on the starter and several almost but not quites, i sat puzzled on the rock hard pad that sits between the tank and tailpiece
Bugger!
I tried 2 or 3 more times on the starter and then decided to give it a little bit of choke.
My wife alerted me to petrol peeing from the carb overflow pipes so I turned the petrol off and left it a couple of minutes.
Bugger!
I tried again without any choke this time and eventually it started after 5 or 6 more goes.
Not a great start as I was expecting a short stab on the button and the sound of a beast roaring into life.
The reality was a little way from that. There was a some smoke but this soon cleared along with my embarrassment of Mrs H rolling her eyes at my last grasp of freedom slowly fading away.
Anyway the bike was idling and revving nicely – sounded great in fact and very responsive.
I didn’t get to ride it that day due to not having sorted my insurance
Anyway curious about the starting issue I decided to pull the plugs (NGK D7EA) and found cylinder 4 was a little black (sooty)
I cleaned the plugs and put the bike away after the rain set in for the afternoon
Well with work and weather other things getting in the way it was a week later that I decided to take it for its first run out
Again, it wouldn't fire straight away but after 5 or 6 attempts using no choke it started up. I had to fiddle with the idle but after a couple of minutes I was able to get it nice and low and it revved cleanly.
So I took it out for the first time. I took it easy at first just to get used to her - she felt good.
I was enjoying my racer - Well apart from the ache in my wrists and my back - but we wont mention that.
I was just pootling around and after about 7 or 8 miles decided to stop and just check if everything was ok.
All seemed well apart from a faint whisp of smoke which seemed to be coming from the pod filter on the cylinder head. I understand this would normally be vented back into the airbox but as my bike is running k&n’s (or similar) the airbox is no longer there.
I also noticed a little weep of oil on the cylinder head too and could see it was coming from one of the valve adjustment caps
But the bike was sounding ok.
As I made my way back home I decided to give her a bit more gas to see how she went.
Riding a bit quicker now and letting the bike rev a little higher and again, all seemed well. I was soon getting into the rhythm of things.
When I got back into town I was riding slowly in traffic and noticed smoke was coming from the exhaust when idling, not a lot, but it was noticeable.
When I got back home I let the bike cool off and again pulled the plugs
Number 4 cylinder was very black and sooty. The smoke being unburnt fuel I suspect.
I wont get chance to look at this until Saturday or Sunday but my initial thoughts are that the float level on carb 4 is either too high or is sticking.
Would this explain the petrol peeing out of the overflow when I first tried to start her up?
Not sure which carb it was coming from but I’m now suspecting it was no 4.
Would this cause bad starting?
What could be the reason behind the smoke after more spirited riding?
Carb needle position?
I am going to check the sparks are ok at the weekend and have a manual on order – don’t really want touch the carbs until I have read the manual.
I have ordered new plugs and plug caps too, as the ones on the bike look original (NGK 5k resistor) and are obviously getting on a bit.
The weep of oil was caused by the valve caps not being tightened properly – 3 of them being only finger tight
Anyway thanks for staying with me if you read it all.
Sorry for such a long first post but would really appreciate your thoughts and input.
Cheers
Darran
It seems I have a little problem with my bike.
Please bear with me and I will try to describe exactly what’s happening.
I bought the bike only a couple of weeks ago after a 15 year lay off from 2 wheels.
It’s a 79 CB550K3 that’s had the café treatment, so the airbox has been removed and its running k&n style filters and a 4 into 1 pipe. Tank and seat unit, clip-ons and rear sets complete the look.
I blatantly ignored all questions from my family asking if i would be alright on that "with my back".
On my first available weekend i proudly rolled the bike out of the garage to start it up and listen to the beast.
Petrol - check
Neutral gear - check
Kill button to run - check
Contact!
Several presses on the starter and several almost but not quites, i sat puzzled on the rock hard pad that sits between the tank and tailpiece
Bugger!
I tried 2 or 3 more times on the starter and then decided to give it a little bit of choke.
My wife alerted me to petrol peeing from the carb overflow pipes so I turned the petrol off and left it a couple of minutes.
Bugger!
I tried again without any choke this time and eventually it started after 5 or 6 more goes.
Not a great start as I was expecting a short stab on the button and the sound of a beast roaring into life.
The reality was a little way from that. There was a some smoke but this soon cleared along with my embarrassment of Mrs H rolling her eyes at my last grasp of freedom slowly fading away.
Anyway the bike was idling and revving nicely – sounded great in fact and very responsive.
I didn’t get to ride it that day due to not having sorted my insurance
Anyway curious about the starting issue I decided to pull the plugs (NGK D7EA) and found cylinder 4 was a little black (sooty)
I cleaned the plugs and put the bike away after the rain set in for the afternoon
Well with work and weather other things getting in the way it was a week later that I decided to take it for its first run out
Again, it wouldn't fire straight away but after 5 or 6 attempts using no choke it started up. I had to fiddle with the idle but after a couple of minutes I was able to get it nice and low and it revved cleanly.
So I took it out for the first time. I took it easy at first just to get used to her - she felt good.
I was enjoying my racer - Well apart from the ache in my wrists and my back - but we wont mention that.
I was just pootling around and after about 7 or 8 miles decided to stop and just check if everything was ok.
All seemed well apart from a faint whisp of smoke which seemed to be coming from the pod filter on the cylinder head. I understand this would normally be vented back into the airbox but as my bike is running k&n’s (or similar) the airbox is no longer there.
I also noticed a little weep of oil on the cylinder head too and could see it was coming from one of the valve adjustment caps
But the bike was sounding ok.
As I made my way back home I decided to give her a bit more gas to see how she went.
Riding a bit quicker now and letting the bike rev a little higher and again, all seemed well. I was soon getting into the rhythm of things.
When I got back into town I was riding slowly in traffic and noticed smoke was coming from the exhaust when idling, not a lot, but it was noticeable.
When I got back home I let the bike cool off and again pulled the plugs
Number 4 cylinder was very black and sooty. The smoke being unburnt fuel I suspect.
I wont get chance to look at this until Saturday or Sunday but my initial thoughts are that the float level on carb 4 is either too high or is sticking.
Would this explain the petrol peeing out of the overflow when I first tried to start her up?
Not sure which carb it was coming from but I’m now suspecting it was no 4.
Would this cause bad starting?
What could be the reason behind the smoke after more spirited riding?
Carb needle position?
I am going to check the sparks are ok at the weekend and have a manual on order – don’t really want touch the carbs until I have read the manual.
I have ordered new plugs and plug caps too, as the ones on the bike look original (NGK 5k resistor) and are obviously getting on a bit.
The weep of oil was caused by the valve caps not being tightened properly – 3 of them being only finger tight
Anyway thanks for staying with me if you read it all.
Sorry for such a long first post but would really appreciate your thoughts and input.
Cheers
Darran
