Honda-SOHC

SOHC.co.uk Forums => CB350/400 => Topic started by: CBNelly on July 24, 2019, 10:33:30 PM

Title: Poor Cold Starting
Post by: CBNelly 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

Title: Re: Poor Cold Starting
Post by: Nurse Julie on July 24, 2019, 11:18:55 PM

Why did you strip the carbs, did you have a problem with them?

Title: Re: Poor Cold Starting
Post by: CBNelly 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

Title: Re: Poor Cold Starting
Post by: Nurse Julie 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?

Title: Re: Poor Cold Starting
Post by: CBNelly on July 26, 2019, 11:15:14 PM

Only have a Haynes manual

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

Title: Re: Poor Cold Starting
Post by: taysidedragon on July 26, 2019, 11:50:45 PM

Look in Aladdins Cave at top of page. In CB400 section.

Title: Re: Poor Cold Starting
Post by: CBNelly on July 28, 2019, 05:46:02 AM

Thanks, I'll set up carbs as per manual and see what happens!

Title: Re: Poor Cold Starting
Post by: CBNelly 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!

 

Title: Re: Poor Cold Starting
Post by: Nurse Julie on August 18, 2019, 07:36:03 PM

Quote from: CBNelly 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!

Yes, fully cover the ports when flaps are closed and all totally horizontal and level when open. Adjust using the adjusters.

Title: Re: Poor Cold Starting
Post by: CBNelly 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

Title: Re: Poor Cold Starting
Post by: Nurse Julie 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