Author Topic: cb400 poor acceleration (Read 13701 times)

flybox1 · « **Reply #50 on:** February 07, 2013, 07:08:54 AM »

NGK D8EA's I hope

I agree about re-checking the pilot jets. screw outs IIRC..

txterror · « **Reply #51 on:** February 07, 2013, 07:21:51 AM »

Pilot jets have been cleaned and dbl checked. Can the dowel be removed, as my wires are outside bars. Or does it need to be cut off. If i need to cut it i rather just leave. Only reason im trying to rotate. is so clutch lever lines up with the brake lever. brake lever is as far as it goes.

txterror · « **Reply #52 on:** February 07, 2013, 08:14:15 AM »

I meant to say NGK caps not plugs, but yes i do have D8EA's on it.

flybox1 · « **Reply #53 on:** February 07, 2013, 08:30:59 AM »

If your wires are outside the bars, then yes, the dowel can be removed or cut off.
5 ohm caps?

just a thinking out loud as the 350F and 400F are somewhat similar.....
the goal of float height is to maintain a certain level of fuel in the bowl at all times. the clymer indicated 21mm for my 350F, but this level kept the fuel level too high in the bowls. The correct level for the 350F is 23-24mms, as confirmed by the clear tube method and HondaMan. This 23-24mm float height keeps the fuel at 4mm below the bowl gasket seam and all the jets in the correct amount of fuel at all times.
21mms made my 350F run rich. i dealt with fouled plugs and difficult starts for quite a while. I surmised that the increased depth of the main and pilot jets at 21mm float height allowed too much fuel through both. things changed for the better when i went to 24mm float height.
might this be the case with yours? I dont know. 400F and 350F have similar carb settings? maybe...
check your fuel level with the clear tube method with your floats set as they are now just to see bowl levels....4mm below the carb gasket seam is the goal

txterror · « **Reply #54 on:** February 07, 2013, 09:01:11 AM »

Caps are XD05F and VD05F.
Im not familiar with clear tube method.
My floats are set at 21mm.....

flybox1 · « **Reply #55 on:** February 07, 2013, 09:27:30 AM »

clear tube method. search for it using the google custom search, top left.
its basically 1' clear tubing out the bowl drain screws, routed upward next to the bowl it comes out of. when the fuel is turned on, it levels out in the tubes, and you can compare that level to the bowl gasket seam line. gives you an external view of the internal fuel level

txterror · « **Reply #56 on:** February 07, 2013, 10:53:29 AM »

Ill give it a try. Can this method be performed while carbs are on the bike?

flybox1 · « **Reply #57 on:** February 07, 2013, 11:07:53 AM »

Quote from: txterror on February 07, 2013, 10:53:29 AM

Ill give it a try. Can this method be performed while carbs are on the bike?

easiest if done off the bike, but if the airbox is off and you have easy access to the bowl drain screws/holes....yes, it can be done.

RickB · « **Reply #58 on:** February 07, 2013, 10:44:33 PM »

Flybox,

I have tried to do this on my CB400F to verify float height and had a difficult time finding a way to do it. I don't have 4 spare bowl drain screws to drill out and as the pitch on these screws is obscure, I couldn't find anything suitable to use as a 'nipple'. I tried plastic garden watering hose plugs, but the pitch is weird. I tried jamming clear tubing in but fuel just ran down the thread.

How did you do it?

Rick.

flybox1 · « **Reply #59 on:** February 08, 2013, 07:17:30 AM »

Hey Rick - heat the tubing with your heat gun, or over a stove while you stretch it from each end. run it under water to cool it fast, then cut it in the stretched center. now you have a tapered tube to twist in the threaded drain screw hole

no leaky.

txterror · « **Reply #60 on:** February 08, 2013, 07:57:43 AM »

I really dont want to take the carbs of "again" so im gona attempt to do this with carbs on bike. I will let you know if im successful. Good question Rick, thanks for the helpful tip flywheel

dave500 · « **Reply #61 on:** February 08, 2013, 12:18:52 PM »

so was the advancer ok?not sticking?

Psychonaut · « **Reply #62 on:** February 08, 2013, 12:59:30 PM »

Quote from: txterror on February 05, 2013, 08:32:22 PM

Pics

I don't know if your pics will show up in this but it looks like your choke is adjusted to be full on with not to much lever. Doi your chokes fully open when they are off?

txterror · « **Reply #63 on:** February 08, 2013, 01:05:12 PM »

yes, choke does open

dave500 · « **Reply #64 on:** February 08, 2013, 01:18:07 PM »

and the advancer?

iron_worker · « **Reply #65 on:** February 08, 2013, 01:18:59 PM »

How did the pilots look?

IW

flybox1 · « **Reply #66 on:** February 08, 2013, 01:31:37 PM »

Quote from: dave500 on February 08, 2013, 01:18:07 PM

and the advancer?

dave, you've got a lot of patience....

Retro Rocket · « **Reply #67 on:** February 08, 2013, 01:43:40 PM »

Quote from: flybox1 on February 08, 2013, 01:31:37 PM

Quote from: dave500 on February 08, 2013, 01:18:07 PM
and the advancer?
dave, you've got a lot of patience....

Haha, you can't see him Fly, he's head butting the wall....

txterror · « **Reply #68 on:** February 08, 2013, 02:06:07 PM »

sorry dave. missed your post. Havent dug out the advancer yet. Im assuming one must remove to inspect?

flybox1 · « **Reply #69 on:** February 08, 2013, 02:07:23 PM »

Quote from: Retro Rocket on February 08, 2013, 01:43:40 PM

Quote from: flybox1 on February 08, 2013, 01:31:37 PM
Quote from: dave500 on February 08, 2013, 01:18:07 PM
and the advancer?
dave, you've got a lot of patience....

Haha, you can't see him Fly, he's head butting the wall....

haha...poor dave

I hope "the blows have a little more space in-between them" Blind Melon - Walk
stop the bloodshed txterror!

dave500 · « **Reply #70 on:** February 08, 2013, 02:07:58 PM »

remove the points cover,its the bit that spins,if you have a timing light rev the engine and watch it advance all the way to the marks,or if no light you can see the mechanism expand as its revved up.

dave500 · « **Reply #71 on:** February 08, 2013, 02:09:16 PM »

its 8 am here,,#$%* it im getting a #$%*ing beer!

txterror · « **Reply #72 on:** February 08, 2013, 02:11:12 PM »

I set timing the other day so advancer is workin, i apologize again dave

txterror · « **Reply #73 on:** February 08, 2013, 02:12:45 PM »

4:12 pm over here, still at work

dave500 · « **Reply #74 on:** February 08, 2013, 02:16:21 PM »

ok you set the timing,did you watch it physically advance?

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Author Topic: cb400 poor acceleration (Read 13701 times)