Author Topic: CB400F Engine rebuild  (Read 6356 times)

Offline taysidedragon

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CB400F Engine rebuild
« on: May 23, 2020, 10:59:25 AM »
I bought a spare engine to overhaul or use parts from for my main engine.
It was reasonably cheap and you can see why from these photos! The tappet covers have been chiselled so hard that one has a hole in it. There's an awful lot of orange silicon gasket on the crankcase join.
I wonder what horrors I will find inside? 😳☹
Gareth

1977 CB400F
1965 T100SS

Offline Greg65

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Re: CB400F Engine rebuild
« Reply #1 on: May 23, 2020, 11:08:31 AM »
Ohhhh, what horrors lurk inside? If it’s just chiselled tappet covers and a bit of orange gunge on the oil filter and joints , ho hi, you’ve got a great spare. Have fun.
« Last Edit: May 23, 2020, 11:10:17 AM by Greg65 »
Keep smiling it makes the management nervous.
Honda CB400 1976
Suzuki GS1000 1978

Offline mattsz

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Re: CB400F Engine rebuild
« Reply #2 on: May 23, 2020, 01:23:21 PM »
I bought a spare engine to overhaul or use parts from for my main engine.
It was reasonably cheap and you can see why from these photos! The tappet covers have been chiselled so hard that one has a hole in it.

That one on the right looks ok - hopefully you didn't end up buying the world's most expensive used-but-good tappet cover...  ;D

Offline Bryanj

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Re: CB400F Engine rebuild
« Reply #3 on: May 23, 2020, 01:31:54 PM »
Just take the cam cover off, you will know immediately if its a boat anchour

Offline mike the bike

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Re: CB400F Engine rebuild
« Reply #4 on: May 23, 2020, 01:38:24 PM »
Ewww.  Not much expertise in evidence.
Where's that 10mm socket got to?

Offline taysidedragon

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Re: CB400F Engine rebuild
« Reply #5 on: May 25, 2020, 12:20:38 AM »
Some good news, some bad.
The cam, followers and bearing faces are good. Plenty of oil in evidence. The valves look like new.
The engine hasn't run since being assembled. Combustion chambers and pistons are as clean as a whistle.

However,  original Honda pistons look like they've been scraped with a knife, badly scratched crowns.
The bores are smooth and clean but no sign of any honing. The rings look new and the camchain tensioner horseshoe is free.

I'll get measuring in my next visit.
Gareth

1977 CB400F
1965 T100SS

Offline Bryanj

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Re: CB400F Engine rebuild
« Reply #6 on: May 25, 2020, 06:14:08 AM »
Could have new rings but not been glaze busted, you can do that with an appropriately sized flap wheel

Offline taysidedragon

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Re: CB400F Engine rebuild
« Reply #7 on: May 25, 2020, 11:54:14 PM »
Didn't do much today,  I had an essential trip to Durham! 🤣

I did find this though. I guess they didn't have a clutch nut tool. 🤨 [ Guests cannot view attachments ]
Gareth

1977 CB400F
1965 T100SS

Offline motty

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Re: CB400F Engine rebuild
« Reply #8 on: May 26, 2020, 07:28:35 AM »
Some people should not be allowed to even touch a motorcycle, let alone work on one

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Offline Bryanj

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Re: CB400F Engine rebuild
« Reply #9 on: May 26, 2020, 07:40:10 AM »
I must admit to having had to do similar, but not that bad, back in early 70's when special tools just were not available to buy unless you were a franchised Honda dealer and they would not order the "special" tools for you even if you were prepared to pay the high price

Offline BlackBomber400

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Re: CB400F Engine rebuild
« Reply #10 on: May 26, 2020, 12:24:23 PM »
This is brutal


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Offline taysidedragon

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Re: CB400F Engine rebuild
« Reply #11 on: June 18, 2020, 07:48:01 PM »
This is what was behind the oil pump. 😫
Gareth

1977 CB400F
1965 T100SS

Offline Nurse Julie

  • 1977 CB550/4 Mongrel Brat. 1974 UK 500/4 K1. Honda CD250u.
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Re: CB400F Engine rebuild
« Reply #12 on: June 18, 2020, 07:54:24 PM »
This is what was behind the oil pump. 😫
Is that yellow mastic 😥😥😥😥
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

Offline Bryanj

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Re: CB400F Engine rebuild
« Reply #13 on: June 18, 2020, 08:26:19 PM »
Orange Heretite silicone i think Julie

Offline Nurse Julie

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Re: CB400F Engine rebuild
« Reply #14 on: June 18, 2020, 08:50:17 PM »
Orange Heretite silicone i think Julie
It could be Bryan. We have found bathroom sealant, white and clear, gutter sealant in black and grey and a green substance which was unidentifiable whilst stripping customers engines. Its always a mystery what we are going to find next 😁😁😁 Unfortunately, the use of these types of goo usually indicate what has not been done correctly within the engine itself by some previous owners.
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

 

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