Honda-SOHC
SOHC.co.uk Forums => CB350/400 => Topic started by: stevush on September 02, 2015, 02:19:08 PM
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Hi all,
I've made some progress with the 400 project and I've managed to get the head and barrels off. The head had suffered some damage in the past (remains of a broken ring maybe) but I think I've managed to salvage that OK. Unfortunately I think that the barrels are going to need new liners or a rebore and I'm looking for an engine reconditioner in the North East who can do it. I've used Cleasby in Durham many, many moons ago for car engines but I'm looking for recommendations from anyone. Unless of course someone on the forum has suitable replacements for sale ?
I'm also having trouble removing the fork tubes from the stanchions, I've undone the bolt in the bottom of the leg but I cant remove it, its just turning and the tubes just aint moving anywhere, any pointers please ?
Thanks
Steve
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Regarding the stanchions, try spraying with WD40, remove the clamp bolts, prise the clamps open slightly with a screwdriver and tap the top with a large hammer. Don't forger to protect the fork caps with some hardwood.
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I think what steve is trying to say is he can't get the fork tubes (stanchions) out of the fork lowers?? Do the 400f forks have an inner retaining circlip that sits above the fork seals? If so, have you removed these? Apologies, not familiar with 400F legs. Graham, Bryan, Rich, Ash?
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Sorry, I misunderstood. There's an M8 Allen bolt at the bottom of the fork leg in the curved bit where the axle goes. When refitting, don't forget the copper washers. Here's a diagram....
http://www.cmsnl.com/honda-cb400f-england_model14639/partslist/F01-1.html#results
The circlip only secures the seals and doesn't need removing to separate stanchion from fork lower.
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Sorry, I misunderstood. There's an M8 Allen bolt at the bottom of the fork leg in the curved bit where the axle goes. When refitting, don't forget the copper washers. Here's a diagram....
http://www.cmsnl.com/honda-cb400f-england_model14639/partslist/F01-1.html#results
The circlip only secures the seals and doesn't need removing to separate stanchion from fork lower.
I am not sure of 400 forks,but with my 500,to remove the allen bolt at the bottom,some times you need to remove the top cap,and
hold the center damper unit,then hopefully the bolt will unscrew,
hope this helps,sorry if it confuses
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Who ever you use make sure you tell them the piston to bore clearance you want otherwise they will make it too big and you will be burning oil
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Last time I stripped 400/4 forks was in 1986 but from what I remember I had the same thing with the forks. Once you got the allen screw loose it just turned the damper rod probably because there had been some sort of thread-lock on the screw. I think I either put slight compression on the spring again or bunged a broom handle down the bore of the leg to put a bit of friction on the top of the damper rod, , pushing down on the bit of broom handle at the same time as attempting to remove the screw.
Ash
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If the bolt is spinning around in the bottom of the stanchion or is mashed up,just drill the head off then pull apart.when u get it separated just take the remainder or the bolt out with pliers.
Simples
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If the bolt is spinning around in the bottom of the stanchion or is mashed up,just drill the head off then pull apart.when u get it separated just take the remainder or the bolt out with pliers.
Simples
If you do do that I would think you stil lneed to prevent the damper rod from spinning while you drill it.
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Always worked for me ash
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Yes, the M8 bolt seems to be just turning the damper rod, maybe bunging something down to hold the damper as Ash suggested is the way forward. Yes, there's a circlip and I've removed it already. I suspect threadlock is keeping the bolt tight. Its not mashed and it 'cracked' OK and was winding out fine but is stuck firm. I'll revisit later. No recommended reconditioners for the barrels ?
Thanks
Steve
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If that doiesnt work, you could try the 'drilling out' Norniron method and possibly nipping up the screw again may prevent the drilling from trying to turn the damper rod.
Not so sure on the cylinders , there are people a lot more qualified on here to comment than me . People say good things about SEP in Kegworth for rebores. You could try secondhand . Trigger & myself use jap2wheelz (Frank) in Germany.. good honest bloke who speaks perfect English or dare I say it our old buddy 'bikepusher'. Also try calling DK and ask for Pete in spares to see if he has any secondhand and if so do a bit of haggling. ( beware of imports left standing though as bores could be corroded but not worn)
Not saying these are any good but worth asking him for more details...http://www.ebay.de/itm/CB400-Four-Zylinder-Kolben-STD-Mass-cylinder-piston-assy-CB400-4-Supersport-/161652216772
Ash
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I've used Cleasby in Durham three times for work on car engines including one "recondition", most recently 3 years ago just for a head skim. Since I don't know if they do much work on air cooled Hondas I would ask to speak to someone first - show then the bores, check what piston sizes you or they can get hold of and tell them the clearance and tolerances that Honda specify.
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Completely by accident I found this on the damper spinning in the forks:-
http://forums.sohc4.net/index.php?topic=123516.0
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Many thanks, pleased it isn't just me having problems!!!
Will try the broomstick method I think
Thanks Guys
Steve
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I had a rotating bolt with some friction left. I took it to my local garage who had an air gun, he removed it with one burst. Best fiver I spent after several hours of frustration. Hope this helps.
Greg
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When i had access to a compressor an air gun with 3/6 drive long allen key never failed
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Here's what I did with mine when I had the same problem, same sort of thing but with a bit of tension thrown in.
http://forums.sohc4.net/index.php?topic=25963.msg266074#msg266074
Cheers
Dennis
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Re bores, I pass them on to my local motorbike shop who sub the job out to a firm nearby, that way the motorbike shop guy can be sure to source the right piston for the job and he knows they will do the right clearences and do a tidy job as he sends a lot of work to them. I think the actual reboringbis done by a firm called Posterns, in Abermule, what is surprising is the lad running the bike shop is able to get nicasil coated bores re bored etc. The bike shop is mid Wales motoX - he does do road bikes too.
Regards fork disassembly - I am a firm believer in the broom handle method, not failed me yet, though there is always a first time. Failing that a mamoth tool supply so you can put together enough extension bits on a sockett set to reach right down to the damper rod - not sure about 400/4 but most times I have done a set of forks there has been an allen head on the top of the damper rod.
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I got mine out by clamping the leg upside down in a B+D workmate bench and compressing it as much as I could against the floor with two people sitting on the bench, then whacked it with a lump hammer and impact driver. Put a bit of wood underneath to save scuffing the chromed nut.
Dave.
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If you look at the Honda shop manual they tell you to apply thread lock to the screw, which means once slackened there is still a fair amount of friction on the threads, which means that the damper rod turns in preference to the screw. So you just need a way of applying friction to the end of the damper rod. Like the broom handle method. Those Honda manuals are great on some things , sadly lacking on others like how to remove the 'cush drive' bushes from the rear hub as used on CB400/F/CB350F, CB250/350K/360G5 etc.