Author Topic: 1975 Honda CB400 Four Supersport Cafe South Africa - #SuperTramp (Read 14480 times)

nvr2old · « **Reply #50 on:** November 11, 2015, 09:42:10 AM »

Quote from: 01Thomas on November 11, 2015, 06:50:08 AM

Wait for the motor to warm up thoroughly before pushing in the choke. The best way to warm her up is to ride her gently while reducing the choke progressiely. It can take 5 or 6 kilometres before she's warmed up properly.

I dunno..my 400F starts immediately with the choke but needs the choke turned off after only about 5 seconds and then idles perfectly...even after months of rest.

Leonardovans · « **Reply #51 on:** November 11, 2015, 10:58:50 AM »

I am stripping the other set of carbs and I have ordered my Dyna S.

Lets see what happens.

Leonardovans · « **Reply #52 on:** November 13, 2015, 03:48:34 AM »

So I have to measure the shaft diameter for the Dyna because apparently there are two, the later CB400F uses the 750 shaft?

I took three different measurements, but not sure which one to give.

Some help please.

enwri · « **Reply #53 on:** November 13, 2015, 05:07:52 AM »

Pretty sure the last picture is the shaft diameter they need.
The sleeve with the points cam can slide off when you pull the counterweights outwards. new one has to go back on the same way.
remember the orientation of the little mark on the edge of the cam to the timing marks for 1-4. (you have a photo anyway)

Herr Supersport · « **Reply #54 on:** November 13, 2015, 09:59:19 AM »

Hi

400 f advancer shaft dia = 13.5 mm
[750 is about 15 mm, if I remeber well]

hope that helps

Daniel

Leonardovans · « **Reply #55 on:** November 13, 2015, 10:07:02 AM »

Does this mean I have the 750 advancer?

Herr Supersport · « **Reply #56 on:** November 13, 2015, 10:14:41 AM »

Don't know - mine was 100% shure the original one - nobody wrenched on the bike before it was mine.

What I know is, that I got an electronic ignition equippment designed for 750 that didn' fit - the centerhole was as mentioned 15mm.

If you like, i can post a picture some time later - im sitting in the train now - advancers are marked with numbers, that show to which bike they belong.

Leonardovans · « **Reply #57 on:** November 13, 2015, 10:35:35 AM »

Please do if it's not too much trouble.

Leonardovans · « **Reply #58 on:** November 13, 2015, 10:49:44 AM »

Also, I saw the little line on the shaft. What does it mean and is it in the correct place? What does it line up too?
I ask because the bike has been worked on by PO.

Herr Supersport · « **Reply #59 on:** November 13, 2015, 12:49:52 PM »

So - finally at home/finito lavoro.

The CB400f advancer is stamped "333".
I think any advancer of a SOHC4 Honda can be used. Hondaman postet [as usual] some very interesting thoughts to that subject - please use the search-function.

As I had in mind, the diameter of the shaft is 13.5mm - see pic.
The mark shows the correct position of the excenter-piece ["OK or 180° inverted"]. Cannot remeber what position fits, you find the description in the shop manual.

Leonardovans · « **Reply #60 on:** November 13, 2015, 10:30:41 PM »

I see. But my shaft measures 15mm and the plate is stamped 333.

Bootsey · « **Reply #61 on:** November 13, 2015, 11:01:51 PM »

Check out this thread - Post #36

http://forums.sohc4.net/index.php/topic,34454.25.html

Leonardovans · « **Reply #62 on:** November 14, 2015, 04:57:17 AM »

Rufus from 4into1 says I need the Dyna S DS1-2 for the CB500 CB550 & CB750 because I have the 15mm shaft. Weird.

Leonardovans · « **Reply #63 on:** November 14, 2015, 05:00:33 AM »

On another note, I started stripping and cleaning the carbs.

I wanted to remove the air screws and then noticed the are different to the other 400Four carbs I have. The ones on these carbs are plastic and I don't think they can be removed.

Any ideas guys?

This is a pic of the ones I am cleaning.

This is a pic of the ones on the bike I am trying to get running.

01Thomas · « **Reply #64 on:** November 15, 2015, 02:08:52 PM »

That plastic air screw is in fact just a pre-historic emissions control device. The tab on one side of the plastic bumps against that aluminium casting (seen in your 2nd photo in the eleven o'clock position). It prevents one from giving the screw a full rotation and was intended to discourage tampering.
The plastic is just a cap that is pressed over the actual brass screw. The sides of the brass screw are splined to give the plastic cap some grip. The plastic cap can easily be prised off and then you will have what's in your 2nd photo.

Leonardovans · « **Reply #65 on:** November 15, 2015, 08:16:40 PM »

Thanks 01Thomas.

Now I have to take them out and run the carb bodies through the ultrasonic again.

marting100 · « **Reply #66 on:** November 16, 2015, 07:44:15 AM »

Hi Leonardo.
I did get the same issue with the larger shaft thing for the cb400F Dyna S.
It's normal as per Larry from Dynatek (great guy and customer service, 2 days later and the larger shaft was at my house)
Contact him!!! (see below)
M

"The majority of 350/400 motors will use the rotor included in the DS1-1 kit.
However, a small number of these machines used a mechanical advance assembly
that has a slightly larger shaft size. In these cases, we include a note in
the kit advising the installer to contact us so the larger rotor can be
supplied at no charge.
Please forward your full name, address and telephone number and we will ship
you the correct rotor at no charge.
Thank you,
Larry Nelson
Technical Support
Dynatek
1-800-928-DYNA (3962)
http://www.dynaonline.com

Leonardovans · « **Reply #67 on:** November 23, 2015, 10:07:58 PM »

So i finally got the carbs clean and assembled. I bench synced them and installed them last night.

At first she really struggled to start and I thought I did something wrong. Then after about 5 minutes of trying she eventually ran. She idled very well.

I think I got the timing set OK, but I bought a timing light and will set it tonight. First time, but I am sure I can do it.

The third cylinder is still running colder than the others, but eventually gets hot. I need to figure out what is wrong here.

I will take her for a ride and see how she runs.

straat-toe · « **Reply #68 on:** November 27, 2015, 03:01:16 AM »

Good progress Leo. 4 is harder than 2 is harder than 1. Could just be fuel supply/clogged jets. or a bad plug on the 3rd cylinder. Thanks for the rings. I started my rebuild last night.....eventually.

Leonardovans · « **Reply #69 on:** November 27, 2015, 08:15:54 AM »

Thanks!! Looking forward to yours getting done.

I think i finally solved the problem. The only thing i never did was change the plugs.

The previous owner told me he had done that less than 1000km ago. So I decided to do it anyway, it's only $10 after all. Also, the bogged carbs obviously fouled the plugs.

So david Silver sell the DR8ESL for our bikes. Now I have read conflicting stories regarding the difference, the R being resistor plugs that should actually be used only with new resistor-less plug caps, and the D8EA that should be used (and were removed today), but the DR8ESL were the only ones available from the bike shop and OMG what a difference. She runs like a rocket now.

I should probably get the stock D8EA eventually, but I don't even know if these caps have resistors in, unless someone with knowledge can tell me otherwise. Or if someone has cut one open to show me. Wait, one of my plug caps are broken, I will cut it open and post the photo here.

I have done the "resistor removal/ replace with brass rod" mod on my CX500, but they actually have resistors, an aluminium rod, and springs that can be removed. I don't see that in the CB400 caps.

Here is a pic of the plugs I removed. From left to right, 1 to 4. Notice no.3 is BLACK.

Stay tued for the cut open plug cap.

straat-toe · « **Reply #70 on:** November 27, 2015, 09:01:10 PM »

Cool. Good job. I can come have a look. You can get new ngk resistor plug caps at tracmac or Craigs,part # xd10f. I run those and the D7ea plugs on my 550s . Easy start and no hassles.

Sent from my GT-I9195 using Tapatalk

01Thomas · « **Reply #71 on:** November 30, 2015, 09:48:15 AM »

Just note that not all resister plug caps are the same, the number in the p/n usually(!) denotes the resistance. For one of my other bikes fitted with an aftermarket Silent Hektik electronic ignitin the resistance must be 5 kOhm, not the more common 10 kOhm.

cheers
Thomas

Leonardovans · « **Reply #72 on:** December 01, 2015, 11:03:20 PM »

So I said I was going to cut the CB400F spark plug cap in half, because I wanted to see the resistor.

Well, here it is. No more wondering.

straat-toe · « **Reply #73 on:** December 02, 2015, 01:07:43 AM »

oooooh. nice cutting.

Leonardovans · « **Reply #74 on:** December 02, 2015, 05:30:09 AM »

Dremel, awesome little tool.

Photography, not so much.

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Author Topic: 1975 Honda CB400 Four Supersport Cafe South Africa - #SuperTramp (Read 14480 times)