Honda-SOHC

SOHC.co.uk Forums => CB350/400 => Topic started by: yorky10 on April 15, 2013, 09:14:14 PM

Title: 400four choke
Post by: yorky10 on April 15, 2013, 09:14:14 PM
can any of you fellow members give me a clue as to why my 400four will only run on full choke,carbs have been ultrasonic cleaned,yorky10
Title: Re: 400four choke
Post by: Bitsa (Ralph Wright - RIP) on April 16, 2013, 09:22:54 AM
Yorky,
Defiantly lack of fuel.In my experience do not rely on ultra cleaning stuff.Had my 750 ones done still ran like crap.Bought a can of carb cleaner and squirted down every hole I could find then high pressure air loads of tiny bits emerged.Also check the main tube what the needle goes up and down in.On the air screw make sure the hole at the bottom is clear too.Then float heights critical.
Hope this gives you help.
Cheers
Bitsa
Title: Re: 400four choke
Post by: Rozabikes Tim on April 16, 2013, 01:03:04 PM
Had similar issues on my 400/4 recently when carbs cleaned (manually). However hadn't given enough attention to air pilot jets. - carb cleaner / air line sorted it.

PS where are you in Derbyshire?

Tim
Title: Re: 400four choke
Post by: yorky10 on April 16, 2013, 06:45:59 PM
hi tim I live southnormanton.not far from alfreton,cheers for info I will try anything,yorky
Title: Re: 400four choke
Post by: Rozabikes Tim on April 16, 2013, 07:47:30 PM
Spooky - guess where I live. Broadmeadows / sth. Normanton.

Small world etc.!

Tim
Title: Re: 400four choke
Post by: yorky10 on April 21, 2013, 11:19:04 AM
hi ,tim,its a small world did you get yours sorted,ive tried every thing,i agree its a fuel problem,i am sick of keep taking carb s apart.yorkygrayfallow.
Title: Re: 400four choke
Post by: Bitsa (Ralph Wright - RIP) on April 21, 2013, 07:01:39 PM
Yorky.
Know what you mean did mine several times but when you sort it the silly grin appears.Keep going and good luck.
Cheers
Bitsa
Title: Re: 400four choke
Post by: Rozabikes Tim on April 21, 2013, 08:33:22 PM
Agree with bitsa. Try, try and try again!

Have you looked at air screw jet. Everything else is pretty accessible to clean I would look there again if I were you.

TIm
Title: Re: 400four choke
Post by: yorky10 on April 22, 2013, 07:33:48 PM
hello all,may have sorted carbs ,filled them up with carbcleaner and got air line on them again,bloody starter solenoid packed up now,think I will give it a rest ,for a few days while I order one.tim I havechecked air screws jets are new orings are new,still enjoying it but bloody annoying.yorky
Title: Re: 400four choke
Post by: yorky10 on May 01, 2013, 05:45:54 PM
fired bike up to day,just same run on choke,not with out,,any one sell me set of carbs,at reasonable price,or even loan me me same .yorky
Title: Re: 400four choke
Post by: steven400/4 on May 01, 2013, 06:26:51 PM
yorky if you find you need any carb parts let me know i have loads of them new and old plus as tim will tell you i,m not far away from you
Title: Re: 400four choke
Post by: D-Rider on May 02, 2013, 11:06:46 AM
The other possibility for running weak is too much air.
Are your carbs seated well on their rubbers and the rubbers to the head?

(had a similar issue on my son's old CB125 recently)
Title: Re: 400four choke
Post by: Rozabikes Tim on May 02, 2013, 05:04:11 PM
Yorky,

As you are just round the corner you can borrow my set if you are really desperate!! The only set I have are on my bike and as you know, they are a pig to get on and off!


Tim
Title: Re: 400four choke
Post by: yorky10 on May 04, 2013, 08:23:59 AM
thanks,for offer Tim but I could not put anyone through taking them off for that,i thought if I could fit a good set and it ran better.well today,i start rebuilding them again,fingers crossed,again thanks for offer,if you or any one as some for sale im your man
Title: Re: 400four choke
Post by: Rozabikes Tim on May 04, 2013, 12:23:33 PM
I'll listen out for the swearing then!!
Title: Re: 400four choke
Post by: yorky10 on May 07, 2013, 07:38:05 AM
can any one tell me where I can get a good exploded picture of fourhundred 4 carbs.please.my book picture,haynes and the American one are oiled up .sad is not.if its not running after this its for sale.yorky.
Title: Re: 400four choke
Post by: mickwinf on May 07, 2013, 10:06:19 AM
Try the CMSL site as they have exploded diagrams of everything. I have been where you are, frustrated with a bike that won't play ball, but keep trying and with help from this forum you will get there! Is there any members nearby who could take a look, two heads are better than one! Also everything else has to be spot on, valve/ignition plugs etc. Good luck!! Mick
Title: Re: 400four choke
Post by: sweetpeauk on May 07, 2013, 10:06:36 AM
http://images.cmsnl.com/img/partslists/honda-cb400f2-england-engine-group-1j-1k-2j-2k_bigma000081e01-4_3e89.gif
Title: Re: 400four choke
Post by: Dan on May 07, 2013, 05:27:39 PM
Only running when on choke definitely sounds like blocked jets. I also had carb issues (bike wouldn't rev past 6000). I know this will be frowned upon by some people but as well as using carb cleaner I ran a thin wire through the emulsion tubes with them out the carbs - down the length of them and through the holes drilled across them. If you use a soft wire, copper for example, rather than something coarse like untwisted brake cable there shouldn't be a problem. It worked for me...
Title: Re: 400four choke
Post by: mickwinf on May 07, 2013, 05:44:20 PM
Did you remove the emulsion tubes to clean them?
Title: Re: 400four choke
Post by: Dan on May 07, 2013, 10:52:33 PM
Yes, and the jets. They just unscrew and you can put a good squirt of carb cleaner into the internal drillings of the carbs while they are out.
Title: Re: 400four choke
Post by: ewanhughes on May 09, 2013, 09:36:42 AM
Hi Yorky, have you seen the document that Tim Boughen has produced?  It's basically a complete run through of the process of disassembling, cleaning and replacing 400/4 carbs.  It's mainly done with pictures and I can honesty say I wouldn't have had the confidence to tear my carbs apart if I hadn't seen it first.  I really is that good!  See link below.

http://www.docstoc.com/docs/97200467/CARB-REBUILD-101

All the best and god luck.

Kenny
Title: Re: 400four choke
Post by: mattsz on January 18, 2019, 12:11:53 PM
Old thread, I know... I've seen many references to Mr. Boughen's document, but it seems to have disappeared from the net.  Does anyone have a source?  Or, does anyone have a copy available?
Title: Re: 400four choke
Post by: paul G on January 18, 2019, 12:39:43 PM
Old thread, I know... I've seen many references to Mr. Boughen's document, but it seems to have disappeared from the net.  Does anyone have a source?  Or, does anyone have a copy available?

I have it but it's too large to attach.
Pm me your email address and I will send it to you. :)
Title: Re: 400four choke
Post by: mattsz on January 18, 2019, 12:56:29 PM
Old thread, I know... I've seen many references to Mr. Boughen's document, but it seems to have disappeared from the net.  Does anyone have a source?  Or, does anyone have a copy available?

I have it but it's too large to attach.
Pm me your email address and I will send it to you. :)

PM sent, thanks!
Title: Re: 400four choke
Post by: paul G on January 18, 2019, 12:58:07 PM
Old thread, I know... I've seen many references to Mr. Boughen's document, but it seems to have disappeared from the net.  Does anyone have a source?  Or, does anyone have a copy available?

I have it but it's too large to attach.
Pm me your email address and I will send it to you. :)
PM sent, thanks!

Done
Title: Re: 400four choke
Post by: paul G on January 18, 2019, 01:10:21 PM
Done Andy

Anyone else  ;D
Title: Re: 400four choke
Post by: Andych on January 18, 2019, 10:58:49 PM
Perfect.. many thanks :)
Title: Re: 400four choke
Post by: mattsz on January 19, 2019, 10:21:30 AM
Old thread, I know... I've seen many references to Mr. Boughen's document, but it seems to have disappeared from the net.  Does anyone have a source?  Or, does anyone have a copy available?

I have it but it's too large to attach.
Pm me your email address and I will send it to you. :)

The US sohc forum has larger size limits, I was able to post it there...

http://forums.sohc4.net/index.php/topic,152810.msg2045081.html#msg2045081 (http://forums.sohc4.net/index.php/topic,152810.msg2045081.html#msg2045081)
SimplePortal 2.3.5 © 2008-2012, SimplePortal