Author Topic: CB 550k3 Throttle problems  (Read 249 times)

Offline davidrsmith

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CB 550k3 Throttle problems
« on: April 19, 2018, 08:40:02 PM »
Hi

Now I'm riding the bike a bit more now the weathers better I have noticed that around 4000 rpm, in any gear, it feels like I'm getting fuel starvation. If I open the throttle a bit more it seems to overcome this and carries on revving.
I have checked the fuel line isn't kinked etc, (I have a fuel filter in line).
I thought I'd read a similar post on here some time ago, but I can't find it.
Has anyone got any ideas?

Many thanks
Dave

Offline Johnwebley

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Re: CB 550k3 Throttle problems
« Reply #1 on: April 19, 2018, 08:46:42 PM »


   what  gear ?

  check plug gaps,

  what colour are the plugs ?

 how does it feel around 8- or 9,000 rpm ?

  we could meet up for a chat at Birdwood ,on the A40 next wednesday ,Biker nite meeting
lifelong motorcycle rider,and fan

Offline Bryanj

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Re: CB 550k3 Throttle problems
« Reply #2 on: April 20, 2018, 01:45:06 AM »
Typical of those push in jets being bloked partially

Offline davidrsmith

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Re: CB 550k3 Throttle problems
« Reply #3 on: April 20, 2018, 02:20:05 PM »
The bike has only done about 200 miles since I got it back on the road, one of the jobs I did was renew all the carb jets. However over the winter I  had to have the cylinder head gaskets replaced and whilst this was being done the mechanic noticed an oily type film in the carb bowls, he thinks it was sort of residue coming from the original tank I had on it. He cleaned the carbs out, so hopefully it isn't partially blocked press in jets, and I have since put a different tank on the bike.


Offline Johnwebley

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Re: CB 550k3 Throttle problems
« Reply #4 on: April 20, 2018, 06:46:29 PM »


  might be worth while getting some REDEX injector and/or cleaner.add it to the petrol,

  it could clean the internals as you ride
lifelong motorcycle rider,and fan

Offline Bryanj

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Re: CB 550k3 Throttle problems
« Reply #5 on: May 15, 2018, 09:05:34 AM »
Those pilot jets will block up inside a month if left

Offline matthewmosse

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Re: CB 550k3 Throttle problems
« Reply #6 on: May 15, 2018, 04:14:07 PM »
I would also go the redex in the fuel route, saved me many carb removals and stripdowns, even on the dreaded k3 carbs. Personally I like the frugal nature of the k3 carbs. On my wife's cb250 nighthawk I got it from so varnished up it wouldn't even start except on a neat spray of carb cleaner to running just fine by using redex and a squirt of carb cleaner to start every day for a week of commuting. In my books I prefer that to a half day minimum of removing carbs, cleaning them and 're fitting.
Got a 500/4 with rust and a sidecar and loadsa bits. nice and original and been round the clock