Author Topic: Poor Cold Starting  (Read 1134 times)

Offline CBNelly

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Poor Cold Starting
« on: July 24, 2019, 10:33:30 PM »
Hi,
Have owned my 400/4 since 1990 and always been a good starter
That was until I totally stripped down the carb assembly!
Now takes ages to get going normally with throttle opened
When started it runs fine
Seems like the choke is not working even though butterflys close and tops lift when apply choke
What should I be looking for on carb set-up?
Carbs currently sat on my work bench and all checks so far have yielded nothing
Help
Thanks
Neil

Offline Nurse Julie

  • 1977 CB550/4 Mongrel Brat. 1974 UK 500/4 K1. Honda CD250u.
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Re: Poor Cold Starting
« Reply #1 on: July 24, 2019, 11:18:55 PM »
Why did you strip the carbs, did you have a problem with them?
LINK TO MY EBAY PAGE. As many of you know already, I give 10% discount and do post at cost to forum members if you PM me direct.
https://www.ebay.co.uk/sch/julies9731/m.html?item=165142672569&rt=nc&_trksid=p2047675.m3561.l2562

LINK TO MY CB400/4 ENGINE STRIP / ASSESSMENT AND REBUILD...NOW COMPLETE
http://www.sohc.co.uk/index.php/topic,14049.msg112691/topicseen.html#new

Offline CBNelly

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Re: Poor Cold Starting
« Reply #2 on: July 25, 2019, 10:18:24 PM »
No, carb strip was to clean and re-plate some external fittings

Ran fine before strip so I think something on re-assembly not right

Offline Nurse Julie

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Re: Poor Cold Starting
« Reply #3 on: July 25, 2019, 11:03:17 PM »
Basics to check...depending on what parts you removed......have you bench synced them and have you adjusted the fast idle adjuster as per the manual?
LINK TO MY EBAY PAGE. As many of you know already, I give 10% discount and do post at cost to forum members if you PM me direct.
https://www.ebay.co.uk/sch/julies9731/m.html?item=165142672569&rt=nc&_trksid=p2047675.m3561.l2562

LINK TO MY CB400/4 ENGINE STRIP / ASSESSMENT AND REBUILD...NOW COMPLETE
http://www.sohc.co.uk/index.php/topic,14049.msg112691/topicseen.html#new

Offline CBNelly

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Re: Poor Cold Starting
« Reply #4 on: July 26, 2019, 11:15:14 PM »
Only have a Haynes manual

Is there a copy of a Honda manual on this site?

Offline taysidedragon

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Re: Poor Cold Starting
« Reply #5 on: July 26, 2019, 11:50:45 PM »
Look in Aladdins Cave at top of page. In CB400 section.
Gareth

1977 CB400F
1965 T100SS

Offline CBNelly

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Re: Poor Cold Starting
« Reply #6 on: July 28, 2019, 05:46:02 AM »
Thanks, I'll set up carbs as per manual and see what happens!

Offline CBNelly

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Re: Poor Cold Starting
« Reply #7 on: August 18, 2019, 07:27:46 PM »
Well, got my carbs back together after fitting new genuine jets, etc. form Mr Silver!

Have a question regarding set-up of the choke

When open should the choke flaps fully cover the inlet port or is there a particular way of setting them up?

Thanks!

 

Offline Nurse Julie

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Re: Poor Cold Starting
« Reply #8 on: August 18, 2019, 07:36:03 PM »
Well, got my carbs back together after fitting new genuine jets, etc. form Mr Silver!

Have a question regarding set-up of the choke

When open should the choke flaps fully cover the inlet port or is there a particular way of setting them up?

Thanks!
Yes, fully cover the ports when flaps are closed and all totally horizontal and level when open. Adjust using the adjusters.
LINK TO MY EBAY PAGE. As many of you know already, I give 10% discount and do post at cost to forum members if you PM me direct.
https://www.ebay.co.uk/sch/julies9731/m.html?item=165142672569&rt=nc&_trksid=p2047675.m3561.l2562

LINK TO MY CB400/4 ENGINE STRIP / ASSESSMENT AND REBUILD...NOW COMPLETE
http://www.sohc.co.uk/index.php/topic,14049.msg112691/topicseen.html#new

Offline CBNelly

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Re: Poor Cold Starting
« Reply #9 on: August 19, 2019, 10:11:27 PM »
Thanks for response

Also have a question regarding setting up of the slides

Honda manual says should be 0-1mm from top of inlet port when throttle wide open

Not easy to adjust while holding throttle open against the spring, is there a measurement you can take from the bottom of the inlet when the throttle is closed?

I seem to recall someone using 1.5mm drill bits to measure this gap, is this right?

Thanks

Offline Nurse Julie

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Re: Poor Cold Starting
« Reply #10 on: August 19, 2019, 10:19:07 PM »
Bryans explanation is spot on and works perfectly.http://www.sohc.co.uk/index.php/topic,17769.0.html
LINK TO MY EBAY PAGE. As many of you know already, I give 10% discount and do post at cost to forum members if you PM me direct.
https://www.ebay.co.uk/sch/julies9731/m.html?item=165142672569&rt=nc&_trksid=p2047675.m3561.l2562

LINK TO MY CB400/4 ENGINE STRIP / ASSESSMENT AND REBUILD...NOW COMPLETE
http://www.sohc.co.uk/index.php/topic,14049.msg112691/topicseen.html#new

 

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