Author Topic: Re-liner, Rebore  (Read 4764 times)

Offline stevush

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Re-liner, Rebore
« on: September 02, 2015, 02:19:08 PM »
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

Offline mike the bike

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Re: Re-liner, Rebore
« Reply #1 on: September 02, 2015, 06:52:19 PM »
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.
Where's that 10mm socket got to?

Offline JamesH

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Re: Re-liner, Rebore
« Reply #2 on: September 02, 2015, 07:01:43 PM »
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?

Offline mike the bike

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Re: Re-liner, Rebore
« Reply #3 on: September 02, 2015, 07:08:47 PM »
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.
« Last Edit: September 02, 2015, 07:10:28 PM by mike the bike »
Where's that 10mm socket got to?

Online Johnwebley

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Re: Re-liner, Rebore
« Reply #4 on: September 02, 2015, 08:12:33 PM »
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
lifelong motorcycle rider,and fan

Offline bytio

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Re: Re-liner, Rebore
« Reply #5 on: September 02, 2015, 10:04:30 PM »
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

Offline AshimotoK0

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Re: Re-liner, Rebore
« Reply #6 on: September 02, 2015, 10:31:27 PM »
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
“Alright friends, you have seen the heavy groups, now you will see morning maniac music. Believe me, yeah. It’s a new dawn.” Grace Slick, Woodstock '69 .. In the year of the Sandcast.

Offline Norniron

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Re: Re-liner, Rebore
« Reply #7 on: September 02, 2015, 10:37:36 PM »
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
1977 400 cafe
1972 500/4
2013 triumph STR675

Offline AshimotoK0

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Re: Re-liner, Rebore
« Reply #8 on: September 02, 2015, 10:48:39 PM »
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.
“Alright friends, you have seen the heavy groups, now you will see morning maniac music. Believe me, yeah. It’s a new dawn.” Grace Slick, Woodstock '69 .. In the year of the Sandcast.

Offline Norniron

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Re: Re-liner, Rebore
« Reply #9 on: September 02, 2015, 10:55:04 PM »
Always worked for me ash
1977 400 cafe
1972 500/4
2013 triumph STR675

Offline stevush

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Re: Re-liner, Rebore
« Reply #10 on: September 03, 2015, 08:09:40 AM »
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

Offline AshimotoK0

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Re: Re-liner, Rebore
« Reply #11 on: September 03, 2015, 08:33:42 AM »
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
« Last Edit: September 03, 2015, 08:38:33 AM by AshimotoK0 »
“Alright friends, you have seen the heavy groups, now you will see morning maniac music. Believe me, yeah. It’s a new dawn.” Grace Slick, Woodstock '69 .. In the year of the Sandcast.

Offline totty

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Re: Re-liner, Rebore
« Reply #12 on: September 03, 2015, 12:50:12 PM »
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.

Offline AshimotoK0

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Re: Re-liner, Rebore
« Reply #13 on: September 03, 2015, 01:08:12 PM »
Completely by accident I found this on the damper spinning in the forks:-

http://forums.sohc4.net/index.php?topic=123516.0
“Alright friends, you have seen the heavy groups, now you will see morning maniac music. Believe me, yeah. It’s a new dawn.” Grace Slick, Woodstock '69 .. In the year of the Sandcast.

Offline stevush

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Re: Re-liner, Rebore
« Reply #14 on: September 03, 2015, 04:15:59 PM »
Many thanks, pleased it isn't just me having problems!!!
Will try the broomstick method I think

Thanks Guys
Steve

 

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