View Full Version : Carb jetting help wanted
Black Knight
21st April 2016, 10:28
Can some kind KBer help me with carb jetting.I own a Honda CL400 that the PO did away with the standard air box and filter and fitted one of those horrible cheap mesh conical pod filters-the ones that keep out house bricks and that's all.Naturally I am not happy running the bike on dirt roads with this "filter" on the bike so I am looking at Unifilter foam filters or similar.The motor is basically an XR400 but when I look at the standard jetting for the CL it is 125 main and 55 pilot while the XR manual states 150 for main and 52 for pilot.While I realise the standard air filter system is vastly different between to two bikes,125 to 150 seems a lot.
When I look at the existing jets in the bike they are still showing 125 and 55 but I suspect that the main has been drilled out but I don't know by how much.
I have yet to fit the Unifilter but suspect that the bike will run rich with the current jetting,to this end can someone suggest to me a starting point as to what size main I should fit as I don't want to spend a fortune buying all the jet sizes between 125 and 150 in an attempt to find the correct one.-Thanks in advance.
F5 Dave
23rd April 2016, 08:59
Oh dear, why do people do this, but then not admit their mistake? Can you see if he still has the airbox?
The mainjet will only affect flat out and shouldn't be too hard to select. However the pilot and needle will be considerably harder and often changing the airjet for a smaller airjet is required.
I'd say the best thing to do is get a std airbox off eBay and run std jets. On an uncommon bike that might not be so easy. Maybe a trip to the wrecker to find if anything else can fit without looking silly.
Black Knight
23rd April 2016, 10:16
They do it for "the look" Dave-I am a great fan of bowing to the clever Honda engineers and leaving a perfectly tuned carb, airbox and filter in place.Fortunately I was given the airbox and filter by the PO but it has a few bits missing,there was also some mods made to the airbox area and while cosmetic,may make fitting the airbox back a little difficult.However I may well give this a try.The XR is a bloody good motor and the thought of throwing bits of dirt and gravel down the carb intake does little for me.Thanks for your advice.
F5 Dave
23rd April 2016, 21:26
I've duct taped and blocked off airbox holes to make bikes run better.
Laava
23rd April 2016, 22:43
Check this link out Chris, could be a good step in the right direction.
https://groups.yahoo.com/neo/groups/HondaCB400SS/conversations/topics/48
Black Knight
24th April 2016, 08:37
Thanks Al-I actually use the CB400SS/CL400 forum quite a bit,I had not gone back the 3 years to search for info so appreciate your post.Time you did a Back Road trip before too much green ice gets established?
Laava
24th April 2016, 09:38
There is a bunch of good buggers doing the old russell rd today from russell down. Probably leaving about now, if they've had their brekkie! Road rats mc. Tempted but got a paint brush with my name on! Did the ride up north to doubtless bay with them yesterday. If you get bored, go seek 'em out!
george formby
24th April 2016, 09:39
Thanks Al-I actually use the CB400SS/CL400 forum quite a bit,I had not gone back the 3 years to search for info so appreciate your post.Time you did a Back Road trip before too much green ice gets established?
:shit: I was thinking exactly that before I read your post. The skid demons are growing on the mainland, too.
Black Knight
25th April 2016, 09:36
There is a bunch of good buggers doing the old russell rd today from russell down. Probably leaving about now, if they've had their brekkie! Road rats mc. Tempted but got a paint brush with my name on! Did the ride up north to doubtless bay with them yesterday. If you get bored, go seek 'em out!
Had to go to Fongers for food and pick up my aged mum in law to give her a break from rowdy grandkids,but 3 bikes did pass us one carrying a pillion,prolly them?
Black Knight
25th April 2016, 09:40
:shit: I was thinking exactly that before I read your post. The skid demons are growing on the mainland, too.
Mark,it is the Councils responsibility to keep roads maintained-I complained about 3 years ago and they promised to come out and fix,then those storms and slips came so I did not persue.I plan and contacting again with a request that they work in with the Whangarei Council as there are some real bad patches South of the border.
nzspokes
26th April 2016, 14:38
Had to go to Fongers for food and pick up my aged mum in law to give her a break from rowdy grandkids,but 3 bikes did pass us one carrying a pillion,prolly them?
Yes. 3 of us at that time. Some stayed another night and some left early.
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