Author Topic: 1975 Honda CB400 Four Project - Rookie (Read 318445 times)

RickB · « **Reply #250 on:** December 17, 2010, 01:27:59 AM »

Hi all,

Today I got the call saying my carb bodies were ready for pickup from the hyrdoblasters. Once again, just fantastic results.

These aren't painted or anything. I'm going to polish the top covers and bowls. Apparently the hydroblasting is a breeze to polish.

I couldn't get the cam out, so it was blasted in place. I'll probably mask the cam wheel area off and paint it with a zinc rattle can.

Then I foiled up the seat and dropped it off to my friend Al at the local surfshop Trigger Bros. He's a guru with fiberglass and offered to make my seat for me!

More shots when I get all this back together. I get the carb bolts and hardware back from the platers on Monday apparently. Let's hope so!

Rick.

HedNut · « **Reply #251 on:** December 17, 2010, 08:08:06 AM »

That hydroblasting worked good!! they look "vintage new!"

malcolmgb · « **Reply #252 on:** December 17, 2010, 01:59:17 PM »

That's a nice Panther, don't recall seeing one as clean as that before and certainly not with a white tank.
They usually have a sidecar attached

RickB · « **Reply #253 on:** December 21, 2010, 04:07:39 PM »

G'day again,

So I got the seat back from my friend Al who fiber-glassed it for me. It looks great but will need a few more layers of glass built up underneath to make stronger. So I'm working on that.

The resin had a green tint in it because it was left over from a surfboard. I don't mind, it's getting painted over anyway. I discovered I'm not very good with resin and fiberglass. I'm way too messy.

So here I was trying to remove a float bowl screw that had stuck. I broke the head off of it trying to remove it, so I tried an easy out extracting drill bit. This time I followed the instructions more carefully and used a spanner. No matter, just like last time, it broke. So now I'm going to need a new float bowl as there's no way I'm getting both the stuck screw and the broken extracting drill bit out.

So I got all my hardware back from the electroplater. It really looks fantastic.

I cleaned every piece with metho and a scotch-brite pad as best I could before giving them to the plater. Obviously if you had access to a sand blaster, it would probably come up better but I'm happy with these regardless.

Replacing needles.

Eagle eye observes would notice I'm missing the fast idle plate. I didn't even know I was missing it until I put it all back together and notice something on the parts list that I didn't have. A quick email to Steve at 400fourbits.co.uk and it's in the mail (albeit, without the spring and ball bearing so I hope that's ok).

Like new! Yep, I know I'm missing the balancers and that screw on the right, hadn't put those one yet.

Now I'm going through Tim's rebuild tutorial and measuring the distances and putting the jets etc back in.

The plater lost the linkage arm on the right of the carb rack. Another part coming from 400fourbits.co.uk.

I'm so happy I rebuilt these as it was a really intimidating thing to do for someone with no idea on how carbs work.

Rick.

fastbroshi · « **Reply #254 on:** December 21, 2010, 04:57:19 PM »

Man those little hardware bits look really great. How much was it to get everything done?

RickB · « **Reply #255 on:** December 21, 2010, 05:33:36 PM »

The plating was $50, the hydroblasting $115. I took them apart in 6 hours, and put it all back together in about the same.

HedNut · « **Reply #256 on:** December 23, 2010, 09:21:26 PM »

BETTER THAN NEW! WOW

fastbroshi · « **Reply #257 on:** December 23, 2010, 09:39:48 PM »

I wonder how those carbs compare to some factory fresh ones?

RickB · « **Reply #258 on:** December 25, 2010, 06:26:18 AM »

Thanks guys.

Well I'm having some trouble setting them up correctly. With the slides all the way down in the throats, the balancing screws and linkage arms aren't perfectly aligned. Also, the max throttle bolt won't reach the cam to keep the slides 1mm from the top of the throats.

This is all before I've gotten to installing the dubious quality Keyster jets etc.

Rick.

fasturd · « **Reply #259 on:** December 29, 2010, 06:25:23 AM »

Whew, I have had 4 400s and I have never tackled the carbs as deeply as you . YOU are a total stud! They look great. I hope the tuning problems don't give you too much of a headache.
Good luck.

kslrr · « **Reply #260 on:** December 29, 2010, 08:53:41 AM »

Use Honda needles. I used the Keyster's on my CB650, they lasted 4 months. They fuel was eating them up.

RickB · « **Reply #261 on:** January 01, 2011, 02:30:31 PM »

Thanks guys. I've ordered the Honda needles and emulsion tubes, as I've been told the Keyster ones I have are inferior. I think DSS is closed over the holiday period so more waiting!

bikeboy · « **Reply #262 on:** January 08, 2011, 02:35:35 AM »

Quote from: RickB on December 21, 2010, 04:07:39 PM

The plater lost the linkage arm on the right of the carb rack. Another part coming from 400fourbits.co.uk.

Rick.

Looks great Rick. I'm glad it's not just me that always seems to come home with less than I went with. No matter how many photos I take, 8 times out of 10, there'll be a clip or something missing

These days, I wait until I have spares before I send stuff out.

That hydro-blasting is the shizzle eh? Haven't seen anything that comes close to the finish.

cheers
ian

RickB · « **Reply #263 on:** January 21, 2011, 04:57:26 AM »

Hi all,

A little slow between updates, sorry guys. I've been working on the bike, just not much interesting to take photos of. New bolts, adjusting things etc.

I've been pushing hard to have everything I can have ready in anticipation of getting the engine back from the mechanic soon. I realise I have been saying that for over a year now, but I'm told it's close. Just waiting on the oil pump o-rings to arrive from DSS then it should be a weekend or two. I can't wait!

Ok so here's what I've been up:

Still working on a seat. I tell you, if someone out there makes a decent cafe seat for the 400F, I'd pay at least $300 for it. This damn seat has been so much work!

I had to cut off the seat hinge. Here I'm touching up the paint. What a shame to mar the powder-coating. I had fussed over cutting this from the start. I wanted to keep it as stock as I could. As above, this seat has been such a pain in the backside I'm past caring.

So it's all glassed up. I've probably got 6 or 7 layers on their now and it's strong enough. You can see I added some carbon fibre that I found in the shed.

As you can see above, I cut was a bit careless with the grinder I think and I took too much out of the edge. Hear I'm glassing in a bit of aluminum to prop the edge up. I'm betting this will cause me problems (like it'll now be too bulky to fit) but I couldn't think of a better way to do it. As I said, if anyone knows of a ready-made cafe/hump seat base, I'm all ears. I really wish Owned would make and sell the alloy seats he is fabricating for his 350/400. They're fantastic.

Right before Christmas I put in an order with Kevin at 400FourStore for a pair of the MC-Again rearsets. Expensive yes, but rearsets are and I wanted a quality bolt on set that I could still use the kick-starter with. So here they are, direct from Japan!

My mates Dad, Simon, fabricated up some custom brackets for my mini gauges out of some stainless steel. Now the sit in together nice and snug.

I sat down to get my wiring sorted out while I wait for the motor. As with everything on this bike, there was a problem. All the connectors I bought from VintageConnections.com were too big! I emailed Del and here's the reason why:

All the Honda Fours use 3.5mm terminals, not 4mm terminals. This is because the Fours have more complex wiring harnesses than other Honda models of the same era and Honda used thinner wire in those harnesses, to reduce their diameter. Naturally, thinner wire requires smaller terminals; hence the change to the 3.5mm parts on all Honda Fours. That change began with the original CB750 sandcast in 1969.

So another thing learnt and another two weeks waiting for parts from the US.

I searched around a found a push-button style gas cap latch. Apparently these were stock up until the mid 70's when Honda changed to the lock and key type. It turns out my 400F tank had this button type attached to it already. I didn't think to look until after I'd bought one. No matter, this one is in way better condition anyway.

I rebuilt my fuel petcock. I had the casing hydroblasted with the carbs. The electro-plater lost the res/off/on plate so I bought a spare from Steve at 400fourbits.co.uk. I got a rebuild kit from DSS and put it all back together this evening. I kept the original gold nut, the replacement nut in the rebulid kit was silver.

So with a freshly rebuilt petcock I went to install it in the tank... And as with everything on this bike, there's a problem. The CB350F tank I have uses a different petcock than the CB400F.

I didn't even know this was different. So after some quick searching it turns out the CB350F petcock is as rare as hens teeth. Or at least only turns up on eBay every couple months. So rather than wait for one of them, I figure I might as well use my perfectly functioning CB400F petcock. I discovered that Pingel make an adapter plate that should fit (I will have to take measurements tomorrow)

This is a 22mm male nut thread and either 34mm or 44mm center spaced bolt pattern. Just guessing, but this looks right. Does anyone know the spacing of the holes on a CB350F tank and the nut width on the CB400F petcock?

I should have the carbs fully rebuilt tonight or tomorrow. The Honda needles and emulsion tubes turned up from DSS earlier in the week. Photos to come once they're done.

Rick.

HedNut · « **Reply #264 on:** January 21, 2011, 05:17:05 AM »

Intriguing...exciting...lots'a details and pictures! As always your build keeps me reeled in and I love it. Good luck with it all... Sooooon... you'll be firing it up and relishing in the glory that you built!!

Cheers!

I wish I could help you with finding a seat...but I can't suggest one other than a universal style (check measurements?)

from:
http://www.roccitycafe.com/store.php

or

http://www.caferacermotorcycle.com/parts.php?search=7&PHPSESSID=12555815ab9580b08499be70857952a9

and there's a handfull more that offer seats....

Good luck!

RickB · « **Reply #265 on:** January 22, 2011, 08:33:00 AM »

Thanks HedNut. I'd rather it not be so intriguing and exciting right now! Enough of the trouble shooting, I just want to ride the thing! As for the seats, there are plenty of after market cafe seats out their yes, but none that I can find that are stated to fit a CB400F. There's just too much guess work in trying to match a 750 seat or a 350 twin etc. I made that mistake with my Giuliari seat. It looked great, but it was sized for a 750, not a 400. Anyway...

So today was surfing first, bike building after that. I got in the shed and put another coat on the frame and start body filling the seat. But before that back to my petcock problem...

So the Pingel adapter plate won't work. As you can see above on my CB350F tank, the bolt pattern is 22mm center-to-center apart, with an 8mm drain hole in between. The nut on the CB400F petcock is 24mm, so it would need to be stepped down or funneled to fit on the plate. I either find someone to fabricate this up (if it's even possible), or find a CB350F petcock. There's a beat up one on eBay right now, so I'm keeping an eye on that.

My built up edge. I glassed over a strip of aluminum. It worked but with a lot of air bubbles. I really should have dammed up an area for the resin to sit in on the edge. It sort of worked well enough anyway.

Using a long sanding block to keep everything straight.

Once I'd sanded everything I used some body filler. I've never done this before so here goes...

It's messy! I'm sure I did this wrong, I couldn't get it to smooth out very well. Here I'm trying to build up the edge, so I was deliberately piling it up but still, it wasn't as fluid as I thought it'd be. It doesn't spread far either.

I've got a lot of sanding ahead of me. I'm calling in the power tools tomorrow.

As you can see, a lot of sanding still to go.

Ok so I made some progress on the carbs. As I mentioned before, the Honda needles and emulsion tubes/needle jets arrived. I'm using those instead of the Keyster kit ones based on the recommendations of you guys.

I made a temporary float height gauge out of cardboard. As per Tim's handy walk-through and the manual, the correct float height for the CB400F is 22mm.

So this was the angle of the float arm from the previous owner.

To get it to barely touch the float valve and be at the required 22mm, I had to bend it down this far. It's almost flat and back on itself. This seems like an extreme change. Am I doing something wrong or was the previous owner way off?

Is that main jet in far enough? As it was the emulsion tube/needle jet needed some firm pressure to seat in over correctly, I can't push the main jet in any further. Should it stick up this far?

My other carb related question is why can't I get the float bowl on? I'm assuming I'm not supposed to pressure this on? It should just sit on easy right? What have I done wrong?

Thanks guys,

Rick.

strynboen · « **Reply #266 on:** January 22, 2011, 09:29:17 AM »

have you turnet the floters right.. ???im not for shure my self..så can not say it for shure

-CB-Jamie- · « **Reply #267 on:** January 22, 2011, 12:31:19 PM »

Once you set the float height when the tang on the float was just barely touching the float valve and not putting any pressure on it you should be right.
Your main jet looks correct on how far they stick out and there will be a little bit of pressure as you put the float bowl on. I think this is to make sure the main jet is kept pressed in fully.

Hush · « **Reply #268 on:** January 22, 2011, 01:27:06 PM »

Looking great Rick, love your work.....Hush.

MoMo · « **Reply #269 on:** January 22, 2011, 06:35:49 PM »

My other carb related question is why can't I get the float bowl on? I'm assuming I'm not supposed to pressure this on? It should just sit on easy right? What have I done wrong?

You do need to put pressure down on the bowl, that contacts the tang that holds the main and keeps it in place.

As far as the float tang, that does not look like any float on any 400f I have worked on. It usually looks more like were it originally was before you reset it, but from your description of the way you set it it does seem as though you did it correctly. With the float just making contact with the float needle the height is measured from the carb base to the bottom of the float...Larry

RickB · « **Reply #270 on:** January 22, 2011, 11:31:43 PM »

Thanks guys, carbs are complete then. Now let's hope they function properly!

RickB · « **Reply #271 on:** January 23, 2011, 06:24:28 AM »

Ok so I've decided to take the seat as it is now to a professional for the final prep and painting. I know my limits and painting is one of them.

The carbs are done! I did the best I could with all the adjustments and measurements. I just hope they work. I am a little worried about the float heights, especially given what you said photolar. But I am confident I measured them correctly so we'll just have to see how they work once I get fuel into them. I have brand new fuel and drain tubes coming. Thanks to Tim Boughen's wonderful guide and over-the-phone advice. Couldn't have done it without ya' mate.

The plater lost a screw for one of the top covers. That's no big deal, easy to replace. However I was left with a metal washer. I had this in my number 4 carb (or is that number 1. The outside one without the choke arm on it) parts container. I can't remember where it came from and I can't see it on the parts fiche. Anyone recognise where it came from?

Rick.

hoodellyhoo · « **Reply #272 on:** January 23, 2011, 08:29:13 AM »

Before you put the carbs back on I would recommend adjusting the fast idle screw on the choke mechanism. (the one that raises the slides when you apply the choke). You don't really have enough room once you get the carbs back on.

As far as the petcock, I've never tried it but a few other hondas from the same era have a similar petcock that may fit. I assume that the reserve tube is probably different at a different height depending on the model. Also, some have a dual output (cb350) but others have a single output (early cb750?) like the 350f. It may be a gamble but search for honda petcocks on ebay and see what you find.

Otherwise everything looks great!

Industrial Rat400f Killer · « **Reply #273 on:** January 23, 2011, 08:39:33 AM »

Every part I have ordered from these guys have been in stock and shipped out promptly. You might ask if they have ref# 5 on this page.
http://www.westernhillshondayamaha.com/fiche_section_detail.asp?section=121164&category=MOTORCYCLES&make=HONDA&year=1972&fveh=2900

RickB · « **Reply #274 on:** January 24, 2011, 08:50:16 PM »

Thanks Rat, I emailed them on your recommendation but they didn't have one. All good, I'm chasing some eBay sellers at the moment.

Hoodellyhoo, I tried my best to calibrate everything as per the manual and Tim's guide. I do need to go over the fast idle though. The linkage arm is a bit suspect but I think it'll hold. I'll post some more questions here when I get to it as I couldn't get some of the tolerances to match what was recommended in the manual so I'm not sure I'm measuring from the correct places.

Anyway, for the time being, I'm happy with them.

I dropped the seat off to a customs place the next town over. The owner, a guy named Rusty, was very helpful and his workshop clean and organized. I have high hopes.

Rick.

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Author Topic: 1975 Honda CB400 Four Project - Rookie (Read 318445 times)