Honda-SOHC

SOHC.co.uk Forums => CB650 => Topic started by: jimv50 on February 15, 2016, 09:13:20 PM

Title: rough idle in current freezing weather
Post by: jimv50 on February 15, 2016, 09:13:20 PM
Can't find anything online but do these bikes run rough when idling in the current freezing weather?
Title: Re: rough idle in current freezing weather
Post by: Norniron on February 15, 2016, 11:25:56 PM
Are you using pods or original filter and airbox?
Title: Re: rough idle in current freezing weather
Post by: jimv50 on February 16, 2016, 04:28:27 PM
All original set up,no 'enhancements', correct good condition plugs etc,runs alright when thoroughly warmed up during a good run.
Just thought the bikes might be  sensitive to the cold.
I've screwed the idle up to 1300 rpm just to stop bogging down at the lights
Title: Re: rough idle in current freezing weather
Post by: hairygit on February 16, 2016, 04:31:14 PM
One possibility is water absorbed by the ethanol in the petrol freezing and partly obstructing a jet due to the inrush of already very cold air.
Title: Re: rough idle in current freezing weather
Post by: jimv50 on February 16, 2016, 05:28:06 PM
Petrol all good, all flushed through after recent fuel tap debacle, all carb bowls drained and petrol looked good.
A thorough spray of carb cleaner will have to be done just in case.
New brass and steel feeler gauges ordered just now to give a bit of  tune up which I hope will help.
The more I do to it the less likely I'll trade it in against a Ducati Monster I've got my eye on.
Title: Re: rough idle in current freezing weather
Post by: jimv50 on February 18, 2016, 02:52:23 PM
RS tools delivered new brass feeler gauges today and air gap adjusted from previous 0.85mm gap to 0.35mm.
Certainly started up on the choke better and ran a bit smoother, will have to wait for another day to see what it's like on a run.
Title: Re: rough idle in current freezing weather
Post by: Bryanj on February 18, 2016, 05:20:21 PM
Why brass feeler gauges? what's wrong with standard steel ones
Title: Re: rough idle in current freezing weather
Post by: jimv50 on February 18, 2016, 08:24:52 PM
Nearly all the guidance on measuring the air gap in electronic ignition systems told me to use the non-magnetic feeler gauges.
I certainly don't know the science behind what may go wrong but for the sake of a few Euro I wasn't taking the risk of either shorting something out or just plain not measuring the gap correctly, and I get another tool in the bike tools box  ;D

PS where in Glos are you, I was born in Thornbury
Title: Re: rough idle in current freezing weather
Post by: totty on February 18, 2016, 09:25:49 PM
Apparently some sensors can be knacked by magnetisng them with feeler gauges. I looked it up when I wondered why I had one brass feeler in a set.
Title: Re: rough idle in current freezing weather
Post by: Bryanj on February 19, 2016, 07:36:58 AM
Didn't know you had electronic ign, Im just south of glos near junct 12
Title: Re: rough idle in current freezing weather
Post by: jimv50 on February 19, 2016, 10:20:30 AM
What was I worrying about? Honda manual shows someone stabbing away with a screwdriver at the pulse generator.
And it seems the bike has 'transistorised' ignition rather than electronic, how things move on..
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