Honda-SOHC
General => New Member Introductions => Topic started by: SandyRob on September 24, 2024, 12:25:42 PM
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Hi, thanks for letting me join the forum, I have a CB400 four 1978 model, I had one back in the seventies so thought it a good idea to get another. It needs a few jobs doing but I think I'm in the right place for some help! Rob.
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Welcome a very original looking 400 you have.
Mine is somewhat less original looking.
.(https://live.staticflickr.com/65535/53411967203_4c6a41f97e_w.jpg) (https://flic.kr/p/2pnQi1g)400 lamp change 2 (https://flic.kr/p/2pnQi1g) by Macabe Thiele (https://www.flickr.com/photos/187487200@N03/), on Flickr
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Welcome to the forum and for owning a 400/4.
Are you aware of the 400/4 50th anniversary event being held by DSS on Saturday? A few members on here (including me) are going.
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Welcome ! My 1st 400F came from Alan Mountains in York originally.... as did my CB750K0
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Hi Laverda Dave, yes I've seen the show advertised but cant go that date, will be at Stafford show next month though.
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Hi Ashimotoko, yes I used to visit Mountains shop as I'm in York.
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Hi McCabe-Thiele (Ted) your bike looks good, very blue, engine looks smart wish mine was like that.
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Hi Ashimotoko, yes I used to visit Mountains shop as I'm in York.
Do you know my mate from York Woody who had York Scooters and before that Acomb motorcycles?
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Hi McCabe-Thiele (Ted) your bike looks good, very blue, engine looks smart wish mine was like that.
It will do with time & effort if you want to - engines are pretty straight forward to paint.
The 400 was my first ever bike rebuild that I started during Covid bought as a none runner. The Tank & Side Panels were painted by the PO that's pretty much the only part that I did not restore aside from cleaning the tank inside that had 12 year old petrol in it.
I cleaned up & painted the engine cases when the engine was fully dismantled, rebored with most bearings replaced.
I fitted a 500 headlamp bowl with an LED headlamp unit unit retaining the old headlamp brackets as a brace for after market fork bracket mounts. Exhaust was a good Motad system, rear seat & dampers replaced by PO so not standard. I had the frame powder coated in a darker blue as I wanted a change from boring black. Part of me wishes I had stuck to black. The Gold Wheels were an indulgance - original hubs wheels rebuilt by CWC.
I do like the sweep of your original front pipes.
.(https://live.staticflickr.com/65535/53411795286_38f5784a65_w.jpg) (https://flic.kr/p/2pnPpUb)400 lamp change (https://flic.kr/p/2pnPpUb) by Macabe Thiele (https://www.flickr.com/photos/187487200@N03/), on Flickr
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Welcome Sandyrob. I am also from York. I don’t own a 400F, though.
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Welcome to the forum.
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Welcome Sandyrob. I am also from York. I don’t own a 400F, though.
Shame on you ! ;D
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Welcome Rob. Your bike looks like it's in good nick. Not too much to do. 👍
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Yes Ash. I’ve had to make do with an inferior 550….. 😉
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Ash.
Has woody retired or relocated?
Oh, and I just remembered. I had a 400/4 back in 1977. You don’t make the same mistake twice….🥹
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Ash.
Has woody retired or relocated?
Oh, and I just remembered. I had a 400/4 back in 1977. You don’t make the same mistake twice….🥹
He's retired and sold the shop to a consortium of dentists. He gave his Vincent 1000 to his son I believe. He still lives in Nun-Monkton.
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👍 Thanks Ash.
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Welcome to the forum, it’s very friendly and there is loads of knowledge and help about the bikes we love. I am currently restoring a 550 four, it was just a bit (loads) worse that I expected when I bought it, I have had some great advice and help so far and there is tons of info in past threads. Also the work shop manuals and parts books ind Ash’s Dropbox are invaluable.
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Welcome to the forum!
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Welcome to the forum, it’s very friendly and there is loads of knowledge and help about the bikes we love. I am currently restoring a 550 four, it was just a bit (loads) worse that I expected when I bought it, I have had some great advice and help so far and there is tons of info in past threads. Also the work shop manuals and parts books ind Ash’s Dropbox are invaluable.
The search facilty is very handy too - just two words entered into the Search Menu can bring up a list of useful replies to previous similar questions going back years. It was whilst searching for something that I came up with a post from 2011 about a book by Tom Ratcliffe - I found a copy on e-bay it was an easy read that I enjoyed - so much of the content was bang on.
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Hi Ash, I used to go to Dave Woods shop for parts and bought my sons moped from him, retired now though.
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Welcome Rob. Your bike looks like it's in good nick. Not too much to do. 👍
Not too much but I think the head gasket is leaking so I need to get that done.
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Welcome Rob. Your bike looks like it's in good nick. Not too much to do. 👍
Not too much but I think the head gasket is leaking so I need to get that done.
Has it affected the compression readings or is it an oil weep?
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Welcome Rob. Your bike looks like it's in good nick. Not too much to do. 👍
Not too much but I think the head gasket is leaking so I need to get that done.
Has it affected the compression readings or is it an oil weep?
compressions are all around 135, it seems to be leaking after a ride out, 5-10 mile from the right hand side, oil on the fins below the head gasket
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That sounds like the O ring on the cylinder head - replacement gaskets are a different thickness since the banning of Asbestos so there are issues when you fit the original O rings that come with the gasket sets.
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OK, so what's the recommended parts needed, which make head gasket set, oil rings, gasket sealant, etc.., plus any advice before I start. Thanks all.
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Hi Ash, I used to go to Dave Woods shop for parts and bought my sons moped from him, retired now though.
Bit of a character Woody ...visited his shop once on a social call and he asked me if I wanted a biscuit with my coffee and then handed me a box of Bonio dog biscuits he was busy munching I went to college with him and another guy Chris Brack, who used to run Acomb Motorcycles. Chris is actually a pharmacist but in the late 70's/early eighties used motorbikes was more lucrative I think. How times have changed ! Woody took over the shop from Chris and Chris got it from the guy who went on to start York Suzuki Centre.
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The 400 rather than an O ring has a tubular rubber sleeve and unfortunately you cant get a longer one, so all you can do is get a gasket kit which will almost certainly pattern not OE, then make sure all gasket surfaces are smooth, flat and clean.
A few of the washers under the head nuts are special sealing ones which by now probably need changing, a Honda part only im afraid.
Take lots of pics as you strip it as some head nuts are specials.
Could well be worth changing the inlet manifolds as they develop cracks and leak as well
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You are right of course Bryan it's not an O ring but tubular in shape - I think it has been suggested that an O ring can be put underneath to try to close the gap, can't remember who mentioned it though.
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There is a genuine complete top set available in the US on ebay, will cost you over$100 though.
Item number 362055099219
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The Vesrah sets work fine, but doesn’t include the cam cover ‘pontefract cakes’. Take Teds advice on the head gasket/o ring dimensions as the Vesrah head gasket has a slightly different thickness. I haven’t used it myself, but I believe the copper spray gasket can be used to good effect….others may have opinions on this.
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Re Head gasket replacement:
OK, thanks everyone, has anyone put together a list of parts and their sizes needed to do this job? as any help would be greatly appreciated.
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You wont get the seals/washers pattern, you have to go gasket set
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That sounds like the O ring on the cylinder head - replacement gaskets are a different thickness since the banning of Asbestos so there are issues when you fit the original O rings that come with the gasket sets.
which "o" ring do you mean, the ones round the dowels or the ones round the oil restrictors? as they look like small seals, or are there some other ones?
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That sounds like the O ring on the cylinder head - replacement gaskets are a different thickness since the banning of Asbestos so there are issues when you fit the original O rings that come with the gasket sets.
which "o" ring do you mean, the ones round the dowels or the ones round the oil restrictors? as they look like small seals, or are there some other ones?
It's over 2 years since I worked on my 400 cylinder head, yes I was referring to the oil restrictor that fits between the block & cylinder head that has an O ring type seal (item32).
I have been slightly confused by Bryans description of a tubular sleeve - I think that is the lower block part. (item31 in my parts book).
The part I am thinking of is item 32 in the parts book I remember that as a typical O ring (1290-333-000) that I thought was the seal that leaks oil as it is insufficiently compressed by the later head gaskets. Sorry I do not know the size of the part or what to use as an alternative. Nurse Julie might know as we discussed it briefly but I no longer have the message. I used the engine gasket set that came with my bike I am not sure of the brand. After measuring my gasket thickness I ended up fitting the rings that were in the kit.
If it helps I might be able to find the Brand as I think I kept some unused gaskets - it was not the Vesrah that is said to be the best.
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Thanks for your reply Ted, I will check my parts list and see whats what. I think I might remove the cam cover for now and re tighten/Torque the head down to see if that needs doing as I was told the engine had been rebuilt before I bought it.
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Thanks for your reply Ted, I will check my parts list and see whats what. I think I might remove the cam cover for now and re tighten/Torque the head down to see if that needs doing as I was told the engine had been rebuilt before I bought it.
Certainly worth trying they always seem easy to reach the torque settings in the manual when fitting the cylinder head - my 400 has done just a tad over 400 miles with no oil leaks to date - touch wood etc.
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If you look up the part number at cms its def a sleeve not an O ring, the 500 is an O ring though
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If you look up the part number at cms its def a sleeve not an O ring, the 500 is an O ring though
You are right Bryan I'm confusing the 400 with my more recent 500 build it is a sort of sleeve shape - I have had it in my brain that someone here suggested fitting an O ring underneath.
Looking again at the 400 manual the upper & lower seals are sleeve shaped not O rings - I should have gone to spec savers.
The lower one looks taller - thats my poor excuse.
This is my block when removed - it does not help my case at all.
At the end of the day you are far more experienced.
.(https://live.staticflickr.com/65535/54028264178_f14a888403_k.jpg) (https://flic.kr/p/2qjhYCb)IMG_20210307_135436 (https://flic.kr/p/2qjhYCb) by Macabe Thiele (https://www.flickr.com/photos/187487200@N03/), on Flickr
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Hi, so on CMSNL Honda 400/4 engine page is it
332 (Pin,Dowel) / 32 (gasket cylinder stud) or
28 (Valve oil control orifice) / 33 (Gasket orifice valve)
which one leaks / needs the extra O ring?
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Ted, i had to go and check on cmsnl to be sure.
In all honesty the 400 was normally so reliable they were only in for service or mot.
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I'm surprised NJ has not added her experience from her 400 engine rebuild as I think that is where the idea originated.
My thinking is do you know where the leak is left or right side, front or rear half of block, above, at cylinder head or below. That should point to where the problem seal is.
I have a feeling someone recorded the original asbestos based thickness for reference.
Update
I found my old post about the oils seal rings, it just read I've sent you a PM from Nurse Julie but I culled a load of my old PM's as part of my housekeeping so the reply has gone.
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Looking back at some old posts a member attributed head gasket leaks to using synthetic base oils.
Also flagged up if re-torquing head to loosen all bolts in sequence then torque up rather than just tightening the odd loose one.
I found this parts list posted by Deano400 This is a list I started to put together a while back. Can't remember if it's complete or accurate but may help you putting your list together.
Diagram Part No. Description Quantity
Gasket Set
D1 107 16173-253-004 Carb insulator O-ring 27 x 2.4 4
C1 277 91302-001-020 Tappet cover O-ring 30.8 x 3 8
D2 18 12209-333-005 Valve stem seal 4
C2 31 12909-333-000 Cylinder stud seal 2
C2 32 12910-333-000 Oil orifice seal 2
C2 276 91301-377-000 Cylinder base O-ring 55.5 x 2 4
C2 14 12191-377-000 Base gasket 1
C1 19 12251-377-000 Head gasket 1
C1 24 12391-333-000 Rocker gasket 1
C1 22 12329-333-010 Breather gasket 1
C1 275 91301-333-000 R oil way O-ring 7 x 1.7 1
D2 280 91305-333-000 L oil way O-ring 5 x 1.7 1
E1 8 11394-377-000 Clutch gasket 1
F2 9 11398-333-020 Sump gasket 1
G2 12 11691-333-000 Alternator gasket 1
Oil Seal Kit
A2 265 91201-300-003 Crank oil seal 30x42x8 1
B2 266 91201-323-005 Crank oil seal 30x45x8 1
C1 267 91201-324-010 Tacho oil seal 6.5x14.5x7 1
E1 268 91202-216-005 Clutch oil seal 14x24x5 1
E1 269 91204-259-000 Kick start oil seal 16x28x7 1
H1 270 91205-333-005 Drive shaft oil seal 34x52x13.5x15.5 1
H1 271 91206-286-005 Gear change oil seal 14x28x7 1
H2 272 91207-333-000 Mainshaft oil seal 34x9 1
Oil Pump O-ring Kit
H2 278 91302-044-010 Oil Pump O-ring 6.9 x 1.5 2
H2 279 91302-377-000 Oil Pump O-ring 15 x 2.5 2
H2 215 41123-516-00 Oil pump O-ring 63 x 2.5 1
Separate Items
B1 45 14401-333-003 Camchain 1
G2 140 23131-323-000 Primary chain 1
G2 139 23114-323-000 Primary drive damper 8
E1 238 90431-292-000 Washer.Lock 16mm 1
G2 239 90433-283-000 Washer.Lock 6mm 1
H1 240 90435-333-000 Washer.Lock 8mm 1
F2 287 91329-590-003 Sump filter O-ring 16.5 x 2.8 1
C1 242 90442-377-000 Seal Washer 18od x 2.2 x 8mm thread 2
F2 283 91315-044-000 R main oil way O-ring 19.4 x 2.8 1
F2 286 91319-300-000 L main oil way O-ring 13 x 2.5 1
F2 282 91314-220-000 F main oil way O-ring 16.4 x 2.4 1
H1 213 35751-333-003 Neutral switch O-ring 11.2 x 1.8 1
A2 285 91317-703-000 Camchain adjuster O-ring 6 x 1.7 1
C1 30 12905-333-000 Oil pipe holder 2
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Thanks, to you all for your help, I'll work out what I need to do, it seems to be leaking from the middle to front on the right hand side of engine.
Thanks, Rob.
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Took the cam cover off and checked the head nuts/bolts, all seemed ok, but two or three of the cam cover bolts were loose/stripped, so next job is head off, don't fancy doing that. Anybody got a good engine for sale? :)
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Hi Sandy don’t be put off by a few stripped threads, quite common on these old machines. Just a bit of repair in the form of helicoils or other thread type repairs.
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I agree with Johnny it's par for the course on 40 year old threads in aluminium.
If you have a pillar drill easy enough to Helicoil as mentioned.
If you are not confident that you can drill at the correct vertical angle most engineering shops will fit Helicoils.
I've only ever done two Helicoils on my carb bowl threads - it was pretty straight forwards tbh my second was so much better than my first - I just lacked a bit of self confidence initially. Easy enough to practice first on a chunk of alloy.
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Hi Sandy Rob
Welcome to the forum I am also in North Yorkshire in Northallerton I currently have a running restoration called Muttely who is a Honda CB550 k3
Enjoy your time here they are a very friendly bunch with lotsa of knowledge here to share,
Best Regards
Nigel