Author Topic: 1975 Honda CB400 Four Project - Rookie  (Read 317430 times)

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Offline ivanhoew

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Re: 1975 Honda CB400 Four Project - Rookie
« Reply #475 on: February 08, 2012, 11:45:27 PM »
rick , heres a quick throtle made by tomasselli i think it was ,you can just see the chrome bit on the bars next to the switches .i dont know if they are still about .



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Offline Retro Rocket

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Re: 1975 Honda CB400 Four Project - Rookie
« Reply #476 on: February 08, 2012, 11:48:41 PM »
Thanks for the advice,

In my mind I was thinking it was the throttle tube up on the bars. A quick search naturally took me to Rick Denoon's website and he makes a keep turn cam that has to be installed on the carb rack.

http://www.denoonsp.com/quick-turn-throttle.htm
http://www.denoonsp.com/prod02.htm

That means removing that pin that holds in the cam shaft on the carbs. The exact same pin that I broke off an extracting drill bit in. Hmm... For another time I think.

Rick.

Hi Rick, mine is actually at the throttle end, either way it doesn't matter... ;)

Mick
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Offline liPPy

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Re: 1975 Honda CB400 Four Project - Rookie
« Reply #477 on: February 09, 2012, 08:22:17 AM »
Have a look at the Venhill Fast Action Throttles: http://www.venhill.co.uk/Magura_Controls_and_Levers/MOTORCYCLE_CONTROLS/TWISTGRIPS/888_VENHILL_FAST_ACTION__PUSH-PULL_TWISTGRIP.html


Thanks for the advice,

In my mind I was thinking it was the throttle tube up on the bars. A quick search naturally took me to Rick Denoon's website and he makes a keep turn cam that has to be installed on the carb rack.

http://www.denoonsp.com/quick-turn-throttle.htm
http://www.denoonsp.com/prod02.htm

That means removing that pin that holds in the cam shaft on the carbs. The exact same pin that I broke off an extracting drill bit in. Hmm... For another time I think.

Rick.

Offline ivanhoew

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Offline dmcgrego

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Re: 1975 Honda CB400 Four Project - Rookie
« Reply #479 on: February 09, 2012, 03:31:20 PM »
Rick,

We are having a lot of the same issues...now that I'm riding the bike I've found that I have an oil leak on the left side of the engine, just like you talked about. My plan is to live with it until I get everything else sorted out. It's not too bad right now, just annoying. I just hope I don't end up with the stripped bolt that you had a little while back!

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Offline RickB

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Re: 1975 Honda CB400 Four Project - Rookie
« Reply #480 on: February 09, 2012, 04:39:45 PM »
dmcgrego,

Yeah that does sound the same. It's not what I would call a critical leak, just a weep that spits off the casings down the entire left hand side of the bike. Especially at highway speeds. It's really only concerning because a) when will it leak too much? b) it makes my gear selector slippery c) it covers my boot in a film of oil.

On Jesse's recommendation, I've tried to take some photos of the offending area after a long ride (hence the grime). You'll have to excuse the crappy iPhone photos, it's all I had on me at the time.





You can't see it to well in these pics but oil does build up on the edges of the lower fins here.



Blurry but you can see that almost no oil is running down the front of the engine.



Here you can see the oil spray on the left side shifter, kick stand and surrounding area. This oily dirt grime mixture actually coats most of the left side of the bike at this height.





I was actually surprised to see how much oil was running down underneath the bike. It appears to run down through the generator cover and down off the sump. I bet if I took the generator cover off there would be some oil sitting in that area.

Perhaps someone else has had similar symptoms as this and found the leak and could point me in the right direction? Head gasket? Those rubber/metal washers in the rocker cover area?

Thanks,
Rick.

Offline jessezm

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Re: 1975 Honda CB400 Four Project - Rookie
« Reply #481 on: February 09, 2012, 05:04:37 PM »
Rick, before I was thinking that your leak was from those two rubber sealing washers in the head, but I haven't heard of those being a problem area before, which is why I suggested taking some pictures.  Do you have oil coming from the front of the engine where those washers are?  The leak on the side of the engine at the head gasket from the pictures looks almost certainly to be from the oil orifice valve between the jugs and head.   As you know, I and many many others have had this seal fail even after a fresh rebuild...  In fact, the last time I had the problem I had actually pinched seals somehow between the head and jugs preventing a proper seal.  The rubber seals are not designed particularly well, it seems; there is only a smidgen of head gasket surface area between these passages and the outside, so with an imperfect seal here, oil will easily find its way out.  I finally bought fresh honda o-rings (they are more like rubber sleeves) for the oil valves and return passages and ended up spraying the head gasket (aftermarket from Japan) very very carefully with Hylomar Blue aerosol (3 light coats, letting it dry a few minutes between each, and NO drips--I practiced on a used gasket first).  For the first time, I do not have a leak there.  Let me know if you want more details

Offline Retro Rocket

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Re: 1975 Honda CB400 Four Project - Rookie
« Reply #482 on: February 09, 2012, 05:27:09 PM »
Rick, clean the engine down and use some Johnson's baby powder to cover the area you think the leak is coming from. Start the bike and watch, the powder makes it really easy to see where the leak is....
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Offline malcolmgb

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Re: 1975 Honda CB400 Four Project - Rookie
« Reply #483 on: February 11, 2012, 03:40:55 PM »
Just a thought but you may have more than one leak, behind the alternator cover is an aluminium plug with an O ring to seal an oil gallery, I have had this.
Malcolm

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Offline RickB

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Re: 1975 Honda CB400 Four Project - Rookie
« Reply #484 on: February 13, 2012, 07:34:26 PM »
Lads,

After cleaning the engine down and watching where the leak is coming from, it certainly seems to be from the head gasket area. My mechanics thinking on this is that oil is seeping under those rubber/metal washers in the rocker are and traveling down the stud and weeping out through the gasket area. Although with the oil pressure in that rocker area and the advice you're giving me Jesse, I am skeptical on that now. Especially as it's only on the left side.

It sounds to me that this oil orifice valve area could be the culprit. Not having rebuilt the engine myself, I'm not exactly sure what/where that area is. Jesse, could you point me to exactly the parts you're talking about:



Is this difficult to get to? I assume I'd have to take the rocker and head off. Is that worth doing for a leak? So far I've put 400 odd miles on the bike since last oil change and the levels don't seem to have dropped all that much even if my boot/engine appear to be covered in the stuff.

Thanks again for the help guys,
Rick.

Offline jessezm

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Re: 1975 Honda CB400 Four Project - Rookie
« Reply #485 on: February 13, 2012, 08:34:56 PM »
Rick, the spot I'm talking about is #28, and the #33 o-ring/seal.  There's one on each side of the head.  I've had none leak, both leak, and just one leak at different points...  If you've got oil on just the left side I'd think that could be a likely culprit.  I've even had an issue with #32 and #332 leaking at the same time, but I think that was from an improper install.  Those round seals, shaped like sleeves, surround the oil valve and sit in a recess in the cylinder but stand proud of the mating surface, so when you torque down the head the seals squish and expand to seal that passageway.  But they just don't seem to do a great job all the time...

Unfortunately, you have to take the valve cover, cam, and head off to get to the seals, and at that point, you better replace the base gasket for good measure.  Or you could just deal with the leak...   If you're lucky, though, it's those other washers, which only requires taking off the valve cover.  Keep us posted

Offline supersports400

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Re: 1975 Honda CB400 Four Project - Rookie
« Reply #486 on: March 06, 2012, 04:18:44 AM »
Hi Rick,

What about the used method to torque the cylinder down ? Since you didn't do the engine yourself, I guess the studs where never re-torqued after a few 100 miles ?

This is my procedure :

Lubricate the threads with molybdenum grease / paste, also the  on the rings and flanges of the nuts.
Torque them in the right order with the given torque minus 10 to 15 % (difference between lubrication and dry torque).

After a few warming up - cooling down procedures, re torque them to the specified torque, so 10-15 more then the first torque values, this is overcome the stick slip of the threads and surface under the washers / nuts.

In most cases this works, but when there is still leaking, I give them an extra 20 to 30 degrees, no toque specified.

If that doesn't solve it, disassemble the head, take a new dry head gasket, check the surfaces of the head / cylinder for damages and / or flatness and solve the issues when something is found, otherwise start all over again with the above procedure.

Make sure you install the Honda head gasket, and Honda O-rings.

Good lucjk,

Jensen


« Last Edit: March 06, 2012, 04:45:37 AM by jensen »

Offline nk140

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Re: 1975 Honda CB400 Four Project - Rookie
« Reply #487 on: March 06, 2012, 04:46:32 AM »
Rick, the spot I'm talking about is #28, and the #33 o-ring/seal.  There's one on each side of the head.  I've had none leak, both leak, and just one leak at different points...  If you've got oil on just the left side I'd think that could be a likely culprit.  I've even had an issue with #32 and #332 leaking at the same time, but I think that was from an improper install.  Those round seals, shaped like sleeves, surround the oil valve and sit in a recess in the cylinder but stand proud of the mating surface, so when you torque down the head the seals squish and expand to seal that passageway.  But they just don't seem to do a great job all the time...

Unfortunately, you have to take the valve cover, cam, and head off to get to the seals, and at that point, you better replace the base gasket for good measure.  Or you could just deal with the leak...   If you're lucky, though, it's those other washers, which only requires taking off the valve cover.  Keep us posted

I have the same oil leak on the left side of the motor in my 350f.  I am going to check those o-rings you describe (#33).  Mine is leaking between the jugs and head.  I will have to check that out when I replace my valve guide seals in a few weeks.

Offline RickB

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Re: 1975 Honda CB400 Four Project - Rookie
« Reply #488 on: March 24, 2012, 03:43:39 PM »
Hi all,

Long time between updates, but that's because I was doing all kinds of stuff!

Guys, thanks for all the feedback and help on the oil leak issues. I've resigned myself to the fact that I'll have to take the head off and use a OEM Honda gaskets and O-rings as I know the ones on their aren't OEM. I just bought the kit from DSS. Poor man pays twice once again! At least I'm confident now it's not those metal/rubber washers.

So I just spent the last two months back home in Australia enjoying the bike and the warm weather. I got a lot done on the bike, and for the most part, I'm happy with where I left it. I would love to mount the vintage fairing one day, but that's not a priority. Really the only thing I didn't get done was mounting the license plate holder directly to the seat. Anyway, here's some things I worked on:



It all started with the wheels. I took them off to get the spokes replaced with stainless steel (because the chrome on the cheap spokes from Thailand flaked off!). So whilst the wheels where away, I took the opportunity to swap out the 1975 swingarm I had on the bike for a swingarm from a CB350F that I had HondaMan rebuild for me. Of course he did a great job and his installation instructions where invaluable. Aside from the performance and safety improvements the rebuilt swingarm gave me, it also doesn't have the rear passenger foot peg mounts on it which makes for a much smoother look.



Once again Pablo's was incredible. After I struggled for hours in the hot shed to get the rubber off the rims, I gave up and decided to get the professionals. Scott at Pablo's was great and took the rubber off for free and reinstalled/balanced them for me for $40 when the rims came back.





Since I had the wheels off I had my spare set of exhaust flanges chromed at Vinnies in Dandenong for $100 ($25 a pop!). Whilst I was at it I had the front rotor bolts, clutch adjuster, those exhaust collar things, the petcock on/reserve/off plate and the carbie hose clamps zinc plated for $40.



I had my friend Cody draw me up a new patch for the 'gang' (totally a tongue-in-cheek joke about how all 3 of use have had VIN number problems). I used an online service called Butler Patches and they were great. Cheap, good quality, great approval process.





Besides being stitched on our jackets, I had the patches sewn onto something called The Magic Tarpit made by a company out in Portland called Poler. It's basically a space-blanket/tarp with tie down holes, a hood and flaps to put your hands in (as modeled by Rhys), but it also doubles as a cover for you bike (like any ole tarp I suppose). Pretty cool 'merch' for the gang I thought.



So I did a lot more to the bike, including getting the cut-down top sterring yoke installed with the new clip-ons and grips and re-wired the rear light (you can see the masking tape holding it on in the above photo!). It looks and handles so much better, even if they hit the tank (have yet to sort that problem out). I'll need to shorten the throttle cables and brake line at some point too. I have photos of how it all ended up looking but they're on my digital camera which I left in Australia! By the way, I'm still looking for a NOS CB350F tank emblem to replace the one I lost on the freeway.

So here are some photos from my trip down the Great Ocean Road in southern Victoria in late February. A lot of traffic because it was a long weekend but still a tonne of fun. The roads outside of Johanna were just incredible. 80mph sweeping bends through forests and early morning sunlight. Just amazing. The road along the Twelve Apostles was great fun too, even in the 35 degree heat!



The camp site at Johanna. Luckily we had our mate Quintin in his van otherwise it would have been a lot less comfortable.



My mate Rhys' BMW 75/7.



My 1975 CB400F (with the CB350F tank).



Marcus' BSA Lightning.



This shot and the following I took on my old Russian Lomo film camera. Not easy winding on film with one gloved hand but worth it I think.





























Good times, good times.

I'm back in the US for a while now. Next up, a CR750 build.

Rick.
« Last Edit: March 24, 2012, 03:46:24 PM by RickB »

Offline Retro Rocket

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Re: 1975 Honda CB400 Four Project - Rookie
« Reply #489 on: March 24, 2012, 04:20:43 PM »
Great shots Rick   ;)
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Offline Hush

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Re: 1975 Honda CB400 Four Project - Rookie
« Reply #490 on: March 25, 2012, 01:52:45 AM »
Great photos Rick, esp the sepia ones, look like old school and very cool.
That little CB400 of yours is not bad for a "piece of #$%*e" you were advised not to buy by a lot of people, it is a testiment to your pigheadedness, a great attitude to have if you are going to ressurect the dead (bikes).
Well done and happy riding.....Hush. :)
I think the thing I most like about motorcycling is the speed at which my brain must process information at to avoid the numb skulls who are eating pies, playing the ukulele, applying make-up etc in the comfort of their airconditioned armchairs as they make random attempts to kill me!!!!!!!

Offline RickB

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Re: 1975 Honda CB400 Four Project - Rookie
« Reply #491 on: March 27, 2012, 04:21:07 PM »
Thanks guys, couldn't have done it without this forum.

Hush, at the time I was so scared of this bike and it's problems in a completely irrational way. People have you convinced that the concept of a 'lemon' is true. But if you approach it from a logical point of view, most problems can be fixed with determination and patients. That's what this bike has given me most, a since of confidence to just get stuck in and give it a shot. No regrets no that I'm through to the other side! Thanks again or the encouragement.

Offline Doctorlumen

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Re: 1975 Honda CB400 Four Project - Rookie
« Reply #492 on: March 27, 2012, 06:33:28 PM »
Truly, Rick...This has been a favorite thread of mine and your attention to detail an inspiration.

So, since no one else has asked......Whats the next basket case build? ;D

Offline Kwality

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Re: 1975 Honda CB400 Four Project - Rookie
« Reply #493 on: March 27, 2012, 07:21:00 PM »
+1.  A great thread with a terrific outcome.  Well done!

Offline Godffery

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Re: 1975 Honda CB400 Four Project - Rookie
« Reply #494 on: March 28, 2012, 07:24:34 AM »
Not so - Rookie - anymore I'd say..!

Offline RickB

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Re: 1975 Honda CB400 Four Project - Rookie
« Reply #495 on: March 28, 2012, 12:03:16 PM »
Thanks lads, I really appreciate the support.

Up next? Saving money to start on a CR750: http://forums.sohc4.net/index.php?topic=89402

Offline rickmoore24

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Re: 1975 Honda CB400 Four Project - Rookie
« Reply #496 on: March 28, 2012, 01:27:22 PM »
Love the photos, really cool stuff.

Rick
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Offline RickB

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Re: 1975 Honda CB400 Four Project - Rookie
« Reply #497 on: June 02, 2012, 09:31:11 PM »
Lads,

It's been awhile. The bike is a different country than me so I haven't had much to post. However I finally found my digital camera (it was in my helmet!) so I have some photos to share.



So my brakes aren't as good as they should be. My rear brake won't lock up and my front brake doesn't appear to be touching the disc even. The rear brake I suspect is due to my rear-sets not being adjusted correctly, but I don't know why the front brake isn't more even. Should it be? The groves you can see above are noticeable if I drag my fingernail across the disc. The bike has approx 1300 miles on it.





Some glamor shots. I have the short Posh mirror on here. Because of the rotation on the brake master cylinder, the mirror doesn't have enough pivot in it to be useful. I'm going to have to figure something out here. You can also see here I've had to bend my exhaust out a little to allow travel of the rebuilt CB350F swingarm.



On that note, here it is. I installed the rebuilt swingarm that HondaMan did for me. I mistakenly sent him a CB350F swingarm (won an eBay listing that said it was a CB400F). Regardless, it appears to be the same size, only the rear axle tabs aren't as smooth and tapered as the CB400F swingarm. It doesn't both me really. I kind of like the more 'racer' look of the CB350F swingarm axle tabs.





Here is the cut-down upper triple tree/steering yoke installed. The regular paint job (ie, not powder coated) is a little brittle, but overall I'm happy with how it installed. A little extra massaging needed to get it in right, but I hope it's all straight.

Now the issue is moving the ignition and gauges to suit the lower profile bar area. Possibly a shorter headlight bucket so I can drop the gauges down. Or be happy with the way it is!



Installed some GP style grips that I got from DimeCityCycles on the Airtech clipons. I love them.

Rick.

Offline strynboen

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Re: 1975 Honda CB400 Four Project - Rookie
« Reply #498 on: June 03, 2012, 11:45:42 AM »
looks fine...but...the brake marster can not be mounted 45 degre..it have to sit almost horsontal..if it can take air in the resuair..the brake vill fail..
if you have mounted new pads..it take some km before they are fitting..so the braking gets better in some time...its the vay the caliber move..it sits not parelel to the disc..so it have to vear in to fit perfekt
i kan not speak english/but trying!!
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Offline RickB

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Re: 1975 Honda CB400 Four Project - Rookie
« Reply #499 on: June 04, 2012, 10:35:17 AM »
strynboen,

Thanks for the info on the pads, I was worried they weren't wearing in correctly.

As for the master cylinder, I know it's an extreme angle but it was mounted on my clubmans like this and it performed fine. However, perhaps an upgrade is in order.

I'd want to keep with the period look, so taking a master cylinder off of a more modern sports bike is out of the question. I wonder if the AP Racing classic master cylinder would work? I'm not sure it it's angled enough. Does anyone have experience or some installed photos of this master cylinder per chance?

Thanks,
Rick.