Author Topic: 1977 400F2 first restore project  (Read 22592 times)

Offline smoothoperator

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1977 400F2 first restore project
« on: October 10, 2020, 06:28:40 PM »
Bought as a runner but not a roller. Went to see the bike before bidding and thought it looked about right for a restore. Plenty to do but on the face of it not a basket case. Engine was demonstrated and started and ran well. Advertised cam chain rattle didn't seem that bad to my, untrained ear. Looked carefully at the crankcase, cam adjusting bolt is snapped off. Signs of oil leak on rhs, confirmed now it's home but it's small. Petrol tap wept whilst it was running. History is interesting as the previous owner had it since 1980 and stored it for much of that time. Oil on dipstick is very clean. Came with a Haynes manual which has clearly been well thumbed by oily fingers and includes hand written notes in a number of the sections. Small box of bits included 1 valve and a set of rocker arms. Receipts show some head work was done including 1 inlet and 1 exhaust valve, in 1981. In the same year it was also treated to a new OEM silencer at £45, which sounds very expensive given the date. Still has OEM silencer, well anyway it says HONDA on it I haven't looked too closely yet.

So anyhow plan is initially to get it rolling as well as running. I've fixed the leaking fuel tap and I'm Evaporust treating the tank which is in pretty good condition really. I've installed a Motobatt MB12U having scoured these pages even though I have a bottle of 1.28SG battery acid in my garage the last 20 years and I still don't get to use it.

Front brake is the current job. Master cylinder is not original I think because there is a manky old spare one in the bits box. The one on the bike is not delivering fluid to the brake caliper. I'm currently working on the spare to see if I can get the piston out of it. It also has a broken mirror stem in it, which I see as potential good practise for removing future horrors. Perhaps someone can tell me if it is the original?

Looking ahead, can anyone recommend me an impact driver? Open to hit with hammer or electric, anything that works really. I have bought a Vessel JIS impact screwdriver No2 but I'm not convinced it's right for some of the bigger screws that are a bit gnarly.



« Last Edit: October 11, 2020, 03:47:21 PM by smoothoperator »
Steve
2017 Triumph Bonneville T100
1977 Honda 400 Four Restored April 2022

Offline Lobo

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Re: 1977 400F2 first restore project
« Reply #1 on: October 11, 2020, 09:01:48 AM »
Hi,
1st up keen to learn whether your CB400F2 is GVHxxS... coz I should have never sold it 🙁.

Secondly, whilst not quite the impact driver you were perhaps considering, if you can spare the £ I’d go an 18v rattle gun - one of those tools you never knew you needed. Will do everything single handed from worn x-heads to wheel nuts...


Offline Nurse Julie

  • 1977 CB550/4 Mongrel Brat. 1974 UK 500/4 K1. Honda CD250u.
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Re: 1977 400F2 first restore project
« Reply #2 on: October 11, 2020, 09:12:11 AM »
Enjoy your project.
LINK TO MY EBAY PAGE. As many of you know already, I give 10% discount and do post at cost to forum members if you PM me direct.
https://www.ebay.co.uk/sch/julies9731/m.html?item=165142672569&rt=nc&_trksid=p2047675.m3561.l2562

LINK TO MY CB400/4 ENGINE STRIP / ASSESSMENT AND REBUILD...NOW COMPLETE
http://www.sohc.co.uk/index.php/topic,14049.msg112691/topicseen.html#new

Online K2-K6

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Re: 1977 400F2 first restore project
« Reply #3 on: October 11, 2020, 09:28:43 AM »
Looks like a good start to work with.

For "Looking ahead, can anyone recommend me an impact driver? Open to hit with hammer or electric, anything that works really. I have bought a Vessel JIS impact screwdriver No2 but I'm not convinced it's right for some of the bigger screws that are a bit gnarly."

I use a drill screwdriver for the cross headed screws as it's able to turn the clutch down and persistently rattle the screws without putting too much torque through them.  So in effect it agitates them rather that overloading.  If face is noticeably chewed,  then "refine" it with a ball pien hammer first to reform the cross,  then tap the bit into the head and it'll get good drive usually.

Offline smoothoperator

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Re: 1977 400F2 first restore project
« Reply #4 on: October 11, 2020, 12:32:14 PM »
Thanks for the replies. Not your old one I'm afraid Lobo, this one is VNA---S. Just ordered some DOT 4+ brake fluid, as this also suits my car which is in need of a top up, hey that's cheaper than replacing the pads and watching the fluid magically rise as I push the pistons back. Ordered circlip pliers for the deeply buried circlip in the Master cylinder. Also been busy setting a google image album to which there should be a functional link below. Only one way to find out...

https://photos.app.goo.gl/atHTWsQE4tgzLgcS8
Steve
2017 Triumph Bonneville T100
1977 Honda 400 Four Restored April 2022

Offline Laverda Dave

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Re: 1977 400F2 first restore project
« Reply #5 on: October 11, 2020, 03:57:11 PM »
The link works👍. I was following that bike on eBay. A very good basis to start from. You may need to grind the ends of the circlip pliars as the circlip is really buried deep in the master cylinder. It will also be full of crud making it difficult to get a grip with the pliars. Give it a good clean before you start and use a pick to remove the crud before going in with the pliars, character building stuff!
1976 Honda 400/4
1977 Rickman Honda CR750
1999 Honda VFR 800FX
1955 750 Dresda Triton
1978 Moto Morini 350 Sport
1978 Honda CB400/4 'Rat' bike
1982 Laverda 120 Jota

Offline Bryanj

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Re: 1977 400F2 first restore project
« Reply #6 on: October 11, 2020, 06:02:29 PM »
I developed a tecnique for getting those out which involved a gas torch and a vice.
Rip out rge wire clip and top hat rubber then with master in vice point the torch flame down the hole towards circlip till alloy is warm, keep torch moving so even heating.
This will normally dispose of the crusty corrosion, especially if wd is sprayed down there whilst hot BUT dont do this inside the house as the smoke and smell is obnoxious AND it may just start a minor conflagration.
Get the circlip to spin in the groove before attempting to remove.
Stripped 10 masters in 30 minutes doing it this way

Offline smoothoperator

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Re: 1977 400F2 first restore project
« Reply #7 on: October 11, 2020, 06:59:38 PM »
Thanks for the encouragement about the bike choice. Just ordered some circlip pliers, funny to think I might be taking my angle grinder to them when they arrive! Due to this hiatus I have at least been regularly squirting plus gas then alternating with evaporust and I can now see the circlip holes. The cylinder moves more freely now and with the Master back on the bars the lever travels all the way back. The cylinder returns on the spring. Heating whilst in a vice will have to wait whilst I build a bench and stick a vice on it. First time project remember. The spare, I think original master is in more of a bad way so I have it soaking in plus gas and set to one side for the time being. Thanks for your help.
Steve
2017 Triumph Bonneville T100
1977 Honda 400 Four Restored April 2022

Offline smoothoperator

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Re: 1977 400F2 first restore project
« Reply #8 on: October 12, 2020, 06:17:55 PM »
Managed to get the Master cylinder apart, internals looked good so gave it all a good clean and put it back together. Refitted and filled with fluid which went through with some pumps on the brake lever however no fluid is making its way to the caliper. Pressure was building up on the brake lever and the flow of bubbles turned into a flow of liquid from the hole nearest the instruments. The hole in the master cylinder that is. So next step is to remove the unit that holds the brake pressure switch. This is proving to be a bit of a pig so I've given it a rest for a while. Also I could do with a socket extension to get at the upper banjo. I need to check the hoses are clear but I'd be surprised to find them blocked.
Steve
2017 Triumph Bonneville T100
1977 Honda 400 Four Restored April 2022

Offline Laverda Dave

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Re: 1977 400F2 first restore project
« Reply #9 on: October 13, 2020, 03:32:27 PM »
Have you had the caliper apart? If not it might be worth it but make sure you soak the bleed nipple before attempting to remove it. You may also have to apply some heat as well, they are very, very easy to snap. If the nipple is stiff turn it slightly the other way first (to tighten it), this normally allows any rust around the thread to break free prior to undoing it normally. The bleed nipple needs to be opened and closed again a good few times when you fill the system with fluid otherwise you will get an air lock. The brake light switch shouldn't give you any problems, I've never seen one leak at the thread and from memory I think the thread has a slight taper to ensure it seals (others with more knowledge may correct me here!). Always use new copper washers as well (or anneal and clean the old ones). A tip I was given some time ago if a system is proving hard to bleed is to pull the brake lever back to the bars and place a zip tie over it and the handlebar and leave it overnight. This forces air up into the master cylinder, it works!
« Last Edit: October 13, 2020, 03:35:23 PM by Laverda Dave »
1976 Honda 400/4
1977 Rickman Honda CR750
1999 Honda VFR 800FX
1955 750 Dresda Triton
1978 Moto Morini 350 Sport
1978 Honda CB400/4 'Rat' bike
1982 Laverda 120 Jota

Offline McCabe-Thiele (Ted)

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Re: 1977 400F2 first restore project
« Reply #10 on: October 13, 2020, 03:59:51 PM »

Secondly, whilst not quite the impact driver you were perhaps considering, if you can spare the £ I’d go an 18v rattle gun - one of those tools you never knew you needed. Will do everything single handed from worn x-heads to wheel nuts...

Why do you call it a rattle gun it looks like a cordless impact driver to me unless Bosch have a different mechanism?

Just realised it's probably "Pitjantjatjara" for Impact Monster.

« Last Edit: October 13, 2020, 04:05:37 PM by Macabethiele »
Honda CB500 K1 (new pit dug out ready)
Honda CB400 four super sport (first money pit)
Link to my full restoration http://www.sohc.co.uk/index.php/topic,23291.0.html

Offline smoothoperator

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Re: 1977 400F2 first restore project
« Reply #11 on: October 13, 2020, 06:57:16 PM »
Not done much since last post as I have been fitting a worktop in the utility room so than I can have the old worktop for a bench I'm building in the garage. The caliper bleed nipple is out. In fact this is where I started, planning to get the piston moving to pop it out so I could check it, thinking it might be seized. I have got the pressure switch housing off and all the brake tubes. So the next job will be to check and clean them, reassemble and have another go. However I plan to see if I can get fluid simply to come through the brake line before it's screwed into the caliper because as yet I have not had even a dribble come through the line. Something along those lines anyway.
Steve
2017 Triumph Bonneville T100
1977 Honda 400 Four Restored April 2022

Offline Laverda Dave

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Re: 1977 400F2 first restore project
« Reply #12 on: October 13, 2020, 08:34:35 PM »
Did you fit a M/C repair kit with new seals etc and were the seals fitted in the correct order (don't go on how it was dismantled, someone may have been in there before you and reassembled it incorrectly). What did the piston bore look like, you need to check it with a magnifying glass to really gauge it's condition. I doubt if the hoses are blocked, it sounds like something is amiss in the M/C and fluid is unable to get down to the hoses. Maybe take one hose off at a time working backwards from the caliper and see how far any fluid is traveling.
1976 Honda 400/4
1977 Rickman Honda CR750
1999 Honda VFR 800FX
1955 750 Dresda Triton
1978 Moto Morini 350 Sport
1978 Honda CB400/4 'Rat' bike
1982 Laverda 120 Jota

Offline Lobo

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Re: 1977 400F2 first restore project
« Reply #13 on: October 14, 2020, 06:02:04 AM »
Hmm, never thought about it Mac... tho’ this stolen from Wikipedia..

“ An impact wrench (also known as an impactor, impact gun, air wrench, air gun, rattle gun, torque gun, windy gun) is a socket wrench power tool designed to deliver high torque output with minimal exertion by the user, by storing energy in a rotating mass, then delivering it suddenly to the output shaft. It was invented by Robert H. Pott of Evansville, Indiana.”

Offline Bryanj

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Re: 1977 400F2 first restore project
« Reply #14 on: October 14, 2020, 07:47:17 AM »
When master cylinders are worked on they frequently need "bleeding" by using a finger over the outlet hole, wear a nitrile glove as brake fluid is nasty.
Then with finger over hole pull in and hold lever, remove finger and replace, release lever and repeat until you feel your finger being pushed off the end by pressure.

It helps if you have the banjo bolt, washers and pipe ready to fit as soon as you have pressure

 

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