Honda-SOHC
SOHC.co.uk Forums => CB350/400 => Topic started by: hondatri on October 20, 2014, 07:53:34 PM
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Hi guys I am putting my 77 400/4 on Bench for winter and need some info I want to replace Cam Chain its Tensioners and adjusters, Anyone who has done have any tips. I will be stripping Top end anyway and Barells plus and I am going to clean Carbs, I have a Haynes Manual but its not clear enough, Any tips appreciated
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You're going to have to split the crankcases to replace the camchain properly, they are endkless. There are some available with a spring link, but if they were any good I'm sure Honda would have used them :o
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Agree with hairygit if you're gonna do it do it right
Cheers
Bitsa
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If you take it to a Honda dealer they would use a DID split link chain. That is why DID do split chains.
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Never did in my day as a mechanic Trig unless it already had one and if I recall right cd and cb175s did.All the step throughs did not if I remember right.
Cheers
Bitsa
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Bitsa, Not the type you use on the old CD's.
This type will require a chain rivet link tool.
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Yep got yer now its come back now.God do I hate memory blanks.
Cheers
Bitsa
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I would suggest to look online for another manual and cross reference what you do, it will save you time and trouble, don't ask how I know it.
Also, splitting the engine is easier than you might think.
Best of luck
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I like getting the motor steam cleaned (not pressure washed) before stripping as it makes sense to get any crap off it before starting, also if you loosen any awkward bolts after cleaning when it's still hot you can avoid some problems with old bolts that have been in there for a long time.
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You need to split the cases to make sure the tensioner horseshoe is ok and normally change the plunger springs. I have paerts book and manual on CD for cost of a beer plus postage
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Plunger springs ?
I thought new ones were N/A ...
but can the old ones be heat treated in some way to restore their original stiffness?
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Thanks Guys for Suggestions I really dont want to drop the engine to split cranks. I am coming up to 80 and still active to ride and maintain. Will re think when bike up on Bench.
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Plunger springs ?
I thought new ones were N/A ...
but can the old ones be heat treated in some way to restore their original stiffness?
Does it matter? The plunger is locked except during tensioning and that can always be aided with the screwdriver-down-the-hole technique.
What happens to the horseshoe thing? Does it wear out at all?
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The chain cuts into the horse shoe near the pivot and burs over the edges. These burrs stop the pivot from moving. There is an article in this months VJMC magazine on the subject.
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I found this book useful.
http://www.amazon.co.uk/Honda-Performance-Portfolio-1972-1978-Brooklands/dp/1855204150/ref=sr_1_24?s=books&ie=UTF8&qid=1413914198&sr=1-24&keywords=Honda+CB400
It has a couple of rebuilds described by different people.
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Hi I am back again I checked compression and got between 80 and 100psi Manual says 170psi so its more work than I thought. I am going to have engine rebored I was thinking of just replacing rings but I think I will go the whole Hog. Bike has done 30K miles. I would like to thank Andrew for the very informative Manual he Emailed me. I have rebuilt a few Triumph engines in the past and would appreciate any Tips people have picked up in the past doing a 400 engine.
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The only real thing you must watch out for on the 400's is the cam chain tensioner. 30K seems a bit low for a compression problem but, you will not know until you get inside.
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Did you try a squirt of oil down the bores to check if the pressure 'recovers' on the compression test? If so, indeed likely the bores / rings, if it doesn't recover may be indicative of valve problems....
Simon
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Did you have the throttles wide open when you did the compression test? It makes a big difference if they are shut, as the cylinder has difficulty gulping enough air to actually compress.
Also, my spare 350/4 engine - which I'm using in the bike at the moment - had less than normal compression and I glaze busted the bores and used the original rings. It doesn't use oil and now has a healthy compression. This was a stop gap measure until I get the original unit back in but it is absolutely fine - I was out on it yesterday.
As some of the others say, the cam chain tensioner is the part to rectify - but they are easily repairable as outlined in my article in the VJMC magazine. Also many folk don't remove the rotor from the crank, saying it's OK to lift out the crank with it attached. I never do it that way as you cannot then renew the crank seal on that end - having spent all of that time and money on gaskets alone, you could be spoiling the ship.
I am writing an article as we speak for the VJMC mag on the rebuild with pics of my original engine, and it will appear in full form on my web site too.
Hope you get sorted with your winter work,
Ian
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Keep it coming Ian (Orcadian) Sounds like you have got some good stuff to share with us there. Never joined the VJMC. Is it worthwhile doing so?
Anyone else got experience of being a member?
Cheers .. AshD
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Hi Ash,
I've been a member of the VJMC for a good number of years and met quite a few good friends along the way. It's a matter of personal choice. Writing an odd article also brings the benefit of a couple of months free membership and allows others to have the info - just the same as this excellent forum. As you might glean from a quick look at my own site, I'm also into other bikes and cars and as a time served Aircraft Engineer with a well equipped workshop, I tackle most jobs deemed impossible (read too expensive) by the dealers and other 'experts' and usually try to engineer out some of the known weaknesses in designs by accountants when doing a rebuild. Now retired and living in Orkney, I have more time to play!
Ian
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Hi Ash,
I've been a VJMC member since buying the 400 project bike a couple of years ago. I find the club magazine pretty boring, but you do get discount on bike insurance, some good stuff on the web site and details of local meets. Most regions meet once a month. However I'm in the The West Midlands who's VJMC club meet has folded up :(. Is was in central Birmingham which wasn't ideal.
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I went to a couple of vjmc meets, not really my cup of tea, i did not have a lot in common with any of them, i felt every one was old before their time, my problem is i still behave like i am in my 30's
pete
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In reply to Orcadian No I did not open throttles when checking compression just fitted gauge and turned over motor nor did try oil in Barrels. I have the Rocker cover off at the moment and wont get near bike for a week But I will temporarily replace it and carry out test as suggested and will post results, Thanks for info.
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Hi me again I had low compression on test around 75psi as suggested I put oil in cyl and compression improved conciderably. I have removed head and barrels The pistons have no marking on top so are they standard (They are Honda pistons) The Dia of pistons is 51'04 mm. I removed adjuster nut on front of engine and using a screw driver I checked the Horse Shoe for movement and it was very stiff to move I used a screw driver on the front and another at the back and rocked the horseshoe and it was stiff but moving . Should I rebore or would I get away with deglazing and new rings. I dont do much milelage, Thanks for help and suggestions so far.
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I recently put new rings in my 500-4
only £15 a bore,and de-glazed the bores using a long slitpin emery strips and electric drill,
the cylinders and rings bedded well
http://tcmlink.com/fiddefault.aspx?cgroup=MATTITUCK&cpagename=BREAKIN
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I'd just fit new rings and deglaze.
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Thanks Guys seeing that there are no marks on Piston Crown can I assume they are standard
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Crap Pete I have your problem except the bonce is 19 and the body 80
Crapper eh?
Cheers
Bitsa
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I thought the Haynes book was ok, personally.
Be prepared to repair (helicoil) some of the tapped holes in the top of the head.
Last time I lifted the lid to check/torque the head bolts a few more threads let go when
I replaced the cam cover.
Using a genuine Honda head gasket is a good idea too.
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Deglazed barrels using borrowed Rotary deglazing tool. Lapped in valves found a broken outer spring on No.1 Exhaust also when I pulled off the Barrels top ring on No 4 Broken( May be my Fault) Bike had been running very rich as all pistons were black carbon I still need to know for sure if pistons are standard as there are no marking on crown. I still dont know if I should split engine to change Cam Chain horse shoe I can rock it with 2 screwdrivers 1 on adjuster and 1 pushing down on horseshoe at rear of engine it moves but not very freely as some resistance felt.
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Pistons were not always sized, look at the ends of the rings closest to the gap for any markings
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Can you get hold of a Vernier Caliper to measure one?
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Go with Bryan here,If they are standard normally a N mark if oversize marked 0.25 etc to 1.00.You may need to use a magnifing glass depending on how good your eyes are.
Cheers
Bitsa
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I have a jewelers eye glass I looked at a couple of rings no marks Whatsoever the piston dia is 50.80 MM. hope this info can help.
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Can you get hold of a Vernier Caliper to measure one?
Bitsa used to have a Vernier, his last relevant post said that if he ever found it, he would nail it to the floor. Did you ever findi it Bitsa? ;D ;D
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Julie
No I bloody well havent.Looks like I will have to buy another one damn shame it was a good un.It probably is now in the local tip in a box of rubbish
Cheers
Ralph
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Hi,
Standard bore is 51mm, best to measure that, but with a piston at 50.8mm, it looks like standard sizes.
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I brought Piston and Rib=ngs to my Friendly Motorcycle Guru Who confirmed it as Standard he said no marks standard only marked when oversize, Order has now been sent off (Christmas fund empty) Does anyone know where I can get a Standard Camchain screw The previous owner just put in an ordinary 6mm bolt with no lock nut.. Thanks Guys for all the help and info as a guy once said I WILL BE BACK. I will keep forum posted on progress
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Hi,
If you are not too bothered about originality try
http://www.ebay.co.uk/itm/HONDA-CB400-FOUR-STAINLESS-STEEL-CAM-CHAIN-ADJUSTMENT-BOLT-LOCKNUT-/281486100722?pt=UK_Motorcycle_Parts_13&hash=item4189e108f2
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Ka Ja
If thats the bit he is after I go along with that looks good.
Cheers
Bitsa
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Hi Bitsa,
I presumed that's the one, it is the only cam bolt I can think of with a locknut
cheers---ken
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Yeah me too mate but been wrong b4
Cheers
Bitsa
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Bitsa, wrong before and saying that repro parts are OK. All in one week. What is the world coming too.
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Trig
Some you win some you lose but some thimes you have to use whatever you can
Cheers
Bitsa
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Hi again Guys enjoy the banter thanks for suggestion.
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Ok guys got the engine back together New piston Rings,Cylinders Honed Valves Ground in New cam chain and a Guide and Tensioner all new Gaskets and seals I want to ensure valve timing is ok I have looked at Manual and not happy with it. The bike has Boyer electronic ign. Got pistons at TDC and with the marks on Cam sprocket lined up the ign marks seem to be off a bit,Any Suggestions
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Sure i went through this with Drew. So here we go again: page 16 and 17 >>> http://manuals.sohc4.net/CB350_CB400/CB400_CB350_SM_1.pdf
Steve, why do we not have a tech page or manual search?
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What did you have in mind?
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They will be off, the "t" mark is for valve timing, the ignition timing marks are "f":))
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They will be off, the "t" mark is for valve timing, the ignition timing marks are "f":))
hondatri does ask: I want to ensure valve timing is ok I have looked at Manual and not happy with it. So it is the T mark at 1.4
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Thanks Trigger that makes more sense than the Haynes Manual. Next Job is to strip and Clean Carbs I see a 4 carb Kit on Ebay has anyone used one of these.
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Hi its me againset up the valves ok On moving the bike stand I found what looks like a spacer Round 2.5" diawith a center hole of1.3" dia wit 2 holes kike for mounting, I cannot see anything similar in Parts Manual Is it off the 400/4
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Oh dear. That's supposed to go under the cam sprocket bolts .
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I thoght as much I dont mind stripping top to fit it I know honda fitted it for a reason But would it matter if I left it off I mounted Cam sprocket and used Locktite on Bolts. I dont see that bit on my Parts book.
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I'm sure as long as they are locktighted they'll be fine.
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Hi,
My 400/4 did not have that piece fitted when I first stripped my motor in 1984, maybe different on some years/models? anyone any thought?
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Hi,
My 400/4 did not have that piece fitted when I first stripped my motor in 1984, maybe different on some years/models? anyone any thought?
Yep !
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The last one I restored DID NOT HAVE THAT.
So me personally would not worry about it providing the bolts do up to speck and have never loctited any off the cam bolts across the range
Cheers
Bitsa
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Thanks for all replies. I have decided to leave well enough alone and hang that bit on garage wall. So its on to Valve adjustments
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Had a rethink after discussing with local motorcycle shop a very experienced man who used prepare racing engines. Ths spacer was fitted to alleviate end float of camshaft, So into workshop
(shed) Heat on and replaced spacer reset timing and valve clearances. Now for carb overhaul Is there any info available on overhaul of the Keihin Carbs.
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Hi,
A bit of a weird one,have checked different parts drawings, but cannot find it in 350-400/4 parts catalogs, except early cam-wheels appear to be solid, so maybe it was a part of the cam-chain wheel pre 1975?
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Forgive me if I am sounding thick how the hell does that stop camshaft end float someone explain?
Cheers
Bitsa
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Forgive me if I am sounding thick how the hell does that stop camshaft end float someone explain?
Cheers
Bitsa
It is too rusty to be any kind of end float.
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Trig
Stumped and out WTH
Cheers
Bitsa
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You luck people. It just so happens here I have for sale one CB400F cam sprocket washer!
[attach=1]
Very rare, sort after genuine Honda part in excellent condition.
Essential for keeping you cam sprocket bolts tight.
Yours for a mere tenner including P&P! Offering here at mates rates before it goes on eBay.
;)
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Lynx
Will have to say never seen one afore so they exist bloody hell well done mate but still think if its not there no disaster
Cheers
Bitsa
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I'm sure it will be fine without. The strange thing is, I've stripped 3 of these engines in the past two years and they all had this part. One was a 1976 bike. Not sure of the others. I think they just get left out.
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Hi Bitsa,
agree with you 100%, no loose cam-wheel screws found on mine despite high revs and heavy handed throttle, will Lynx's bit be the new must have item worth tens of pounds on fleabay.
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KA jA
Christ your right they will rocket now convinced sellars watch this site to find out what us people want
Cheers
Bitsa
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Better buy mine while you still can! Haha.
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I would but aint got a 400 four no more
Cheers
Bitsa
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I have only come across 2 of those in all my years and both were the 1976 engines.
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Trig
Apart from what you said is there any other differences for that year?
Cheers
Bitsa
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Thanks guys for the banter. I will give it a rest until New Year. I am still looking for info on Carb overhaul I remember seeing something on another forum but cannot remember where.HAPPY CHRISTMAS TO YOU ALL AND SAFE RIDING IN THE FUTURE.
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Trig
Apart from what you said is there any other differences for that year?
Cheers
Bitsa
In the engine ? No. The cam washer has never been on any microfiche for the 400 that i can find. Can't even find a part number for it but, if i have found one on a re-build i put it back.
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I was getting my Exhaust ready for fitting and discovered that the Lip on tthe Engine end (Pushes on gasket) was missing found it on garage floor going to get a mate to mig weld it back on fingers crossed. Dont want to buy a pipe
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I dealt with Dennis at noxandrattles who supplies Stainless Parts for 400/4 He told me he had stripped lots of 400/4 engines and never came across a washer on the camshaft, Today he contacted meto let me know he was doing the Topend of a 400/4 and lo and behold there was a a washer on the camshaft.
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I dealt with Dennis at noxandrattles who supplies Stainless Parts for 400/4 He told me he had stripped lots of 400/4 engines and never came across a washer on the camshaft, Today he contacted meto let me know he was doing the Topend of a 400/4 and lo and behold there was a a washer on the camshaft.
Could it be a spacer shim, so only there if needed?
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What do you mean by a washer on the cam? The two bolts that hold the gear onto the camshaft don't have washers, if they're there then somebody non-Japanese has put them there
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Mike
It is not washers on the 2 bolts its like a second shim almost the same size as the cam sprocket
Cheers
Bitsa
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Its all in the terminology guys. Washer/Shim it appears on very few engines apparently. Why I dont know
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Same here wierd
Cheers
Bitsa
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Its all in the terminology guys. Washer/Shim it appears on very few engines apparently. Why I dont know
Because someone set the machine wrong, so a shim was needed to correct the mistake ;)
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Nice thought and probably right there mate ;)
Cheers
Bitsa
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Nice thought and probably right there mate ;)
Cheers
Bitsa
You will find it on a run of engine numbers ;)
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Yeah believe that too
Cheers
Bitsa
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Getting there with the Old Girl. Got the Carbs on today with help from my Son. Two heads and four hands are best.