Topic: no wonder it seized up!

[Magpie]

Hey Mick!
It's interesting following your progress as I'm doing the same as you with a late '69/early'70 motor that's been under a workbench for 30+ years. I had to split the cases to get the rods, pistons, and cylinders off as one piece, then press the pistons out. The bores look good but I'll need a pro to tell me that. The pins will have to be pressed out too. Will probably need pistons. Lots of surface rust on bits too.
Keep the reports coming please.
Cheers,
Cliff.

[supersport_CB400F]

I’ve been lucky Mick I managed to use all Honda parts in my engine rebuild most new and some used but perfect (expensive though) I personally will not and have never used anything else in my engine. The only experience I have with pattern parts in the past is problems that came up when other people have used them. If you can’t get Honda parts or you have a budget, go your way Mick I’m probably just stuck in my ways but I’m happy.

Cheers
Dave

[Sam Green Racing]

cheers for your comments fellas , Bryanj your gear will be in the post tomorrow & thanks for the offer

of the cam and carriers but i already have another set,

i managed to split the casings today but not before i had 1 10mm stud snap on me & 1 gudgeon pin

was welded in had to use blow torch and WD40 to shift the bugger , after i got it off i noticed

that i had bent the conrod even though i had supported the piston with wood  ,

so my first question is does anyone know if a k7 conrod will be the same as a f1? as i have a spare

crank with rods out of a k7.

i have also been on to Dave silvers to price up a complete gasket and o ring set also a complete oil

seal set , cam chain, primary chains but he does'nt have all genuine parts?

complete gasket & o ring set pattern £39,

complete oil seal kit pattern £19,

primary chains 2 of oem £39,

cam chain pattern £15

has anyone had experience with the pattern parts mentioned ? Den? Dave? Bryanj? Sam? ,

i will post some pictures tomorrow   ,    mick.

Hi Mick, sorry to hear of your dilemma, I have had a long weekend off and have only just seen the post.
With regard to patern parts for the big fours, I can't help as the motor in the CR is stock and came to us as a runner.
The only parts I put in it was cam and primary chains, all genuine parts.
however, over the years I have used patern parts in the Benlys with no problems.
Best of luck mate, keep us posted.

Sam.

[mcpuffett]

cheers Dave & Sam , i will ring silvers tomorrow ansd see if they can order me some genuine Honda parts , i would rather have the proper stuff in there as i dont want to be doing it again soon ,  mick.

[Jerry Rxman Griffin aka MuthaF'er]

I think if you cross reference part numbers you will find the F & K rods you have to be the same. The K7 is the same engine as the F0/F1 (US model). Make sure you get one with the same weight markings (A, B, C, D, E, F, G, H, J, K) as indicated on one side of the big end of the rod. The shop manual lists A, B, C, D as the same part number; E & F the same number; and G, H, J, K the same number. Even though they have the same part number within a group of letters the weights would be slightly different if the letter designation is different. Ideally you would not only have a rod with the same letter but the weights would be equal. Each rod I just removed from my K8 engine was a D for example unlike my first wife which was a double D. 

[spitfire]

Hi Mick,     
           Just did the top end of my F1, all the parts came from David Silvers, i used a genuine Honda head and base gasket but used the after market gasket set for the rest, it does not contain the "O" rings for the oil passage ways though (11X2.5) they have to be ordered seperately. Several of the dowels were in poor condition so I replaced them as well (head to barrels/barrels to crankcase) one of them was so bad it took me a long time to seperate the barrels from the crankcases (rust). The rest was fine, Honda piston circlips and one set of rings, I don't know wether there is a shortage but the rings sent out to me had a solid oil scraper ring but I had a spare three piece one anyway.

Cheers

Den

[bryanj]

Fit the complete crank and rods assembly OR all 4 rods as they are weight balanced. As to DSS and his pattern parts he has too good a reputation to sell anything that isnt up to spec. I have used the cam chains before with no problem and the gaskets I have used have been OK as long as the gasket surfaces are mirror finish clean and flat. Personally i would try and replace all the rubber parts on the cam chain tensioner and cushion as they are way old and have been very hot.

[mcpuffett]

Thanks for the info Den & Bryan, i have managed to get everything out of the casings today and it all looks ok but plenty of rust and muck about , heres a picture of the crank and all the bits sat in the lower casing

[mcpuffett]

and here's some pics of the bent rod and its numbers

[mcpuffett]

Bryan or anyone , can i not just get another rod with the same numbers and replace like for like ?

any help would be gratefully accepted,     cheers mick.

[Jerry Rxman Griffin aka MuthaF'er]

Mick,

Yes, you can use another rod. You need to match the weights of each of the 4 rods. If you'll notice in your 3rd picture, on the side of the rod where the rod and the cap join, there is a letter on one side (which I can not make out) and a number on the other side. The letter is the weight designation. This MUST be the same on all 4 rods (won't get into exceptions like removing weight to make equal if the letters are different here). If the letters are the same then go for it. The number is for initial fittings of the bearing inserts which is not as important since you will be refitting the bearings anyway. This is another topic that is a necessity but let's keep them seperate for the sake of simplicity. Forget about the letters &/or numbers on the rod shaft and cap bottom. There are a few other issues involved with putting all the pieces back together that you will need to understand too when the time comes.

Now, what Bryan was referring to is a very valid option. Replace the crank and rods as a unit. There are potential issues here to that you would need to address when installing. 

Any of this work at this point is very critical for the longevity of the engine. Take it slow and be sure you understand.

Jerry

[heffay]

You will probably find its the cam that has picked up in the towers with the oil jets blocked

picked up?

[spitfire]

Hi Mick,
           Just looking at the photo of your camshaft, seen quite a few like it in the old days, plus a couple with snapped camshafts, hope you have laid out everything in the order that you stripped the motor, the real key is to make sure that everything is super clean when you rebuild and make sure that all bearings are liberally lubricated, do not put too much oil in the barrels though.
To protect the cam on initial start up I always used to pour some oil into the cambox in the cam bearing area, do not fire up the engine until you have spun the motor up and see oil spraying around the cambox (plugs out kill switch to off), this happens after the oil light has gone out so do not be fooled, the oil light can be off and oil is not reaching yet the cam.
I would go with the transplant of a complete crank and rods rather than try to match a rod, all you have to do then is match the bearing shells for the mains.

Cheers

Den

[mcpuffett]

cleaned the casings inside & out today and ordered ,

gasket set, oil seal set, primary chains , cam chain, gudgeon pin circlips from dave silvers  ,

here's the pictures , mick.

[Hop on a Honda]

That looked almost the same as mine when I disnantled it
The #4 cam tower was nuked and the cam too.
The oil diffuser in the head was blocked with what looked like dead cheap oil filter cartridge.
There was a lot of cam chain tensioner guide & roller in there too.
What a mess.
New cam, rockers and shafts, towers and rearrangeing of the valve springs properly helped the rebuild no end
Dave Australia.

[Terry in Australia]

G'Day Mick, it's a pity you live so far away, I've got a good crank and rods that you could have for say, a bottle of JD? (plus shipping, of course!) Cheers, Terry.

[bryanj]

I still say use the other crank as it will save hours and you know it ran, maybe new shells in the ends BUT you will have to platigauge the mains for clearance. try http://www.agriemach.com for platigauge if you cant get any locally.

Deffinately new rubber bits in the cam chain tensioner and possibly primary tensioner as well.

Have you got access to a compressor? if so give me a ring about top end buiding

Cheers mate
Bryan

[spitfire]

Hi Mick,
         I'll probably be burnt at the stake by the experts for suggesting this but in my previous incarnation as a bush mechanic I would probably have bent the conrod back into shape and re use it, saves a lot of hassle, there's probably enough slop in the piston/rod/gudgeon pin area to cope if it isnt 100% straight. Have you got a friendly engineering shop nearby that could straighten it ?

Cheers

Den (ducking)

[bryanj]

Spitfire, in my last incanation before driving heavies I had to "Bend" several rods for the Students to check out on a special jig and dur to the stresses incured in the metal in bending and straightening i wouldnt do it unless it was one of the last rods in the world and the engine was not going into service for more than a few hours a year--and then at WAY reduced revs/load

[spitfire]

Damn another master plan bites the dust.

Cheers

Den

[supersport_CB400F]

Hi Mick,
         I'll probably be burnt at the stake by the experts for suggesting this but in my previous incarnation as a bush mechanic I would probably have bent the conrod back into shape and re use it, saves a lot of hassle, there's probably enough slop in the piston/rod/gudgeon pin area to cope if it isnt 100% straight. Have you got a friendly engineering shop nearby that could straighten it ?

Cheers

Den (ducking)

The Wirral is the outback/bush isn’t it! 

[spitfire]

Gets a bit wild down the Tap !

[mcpuffett]

Right i will try again friggin computers  , cheers for the comments fellas, i think i will keep my crank and swap the rods as i dont know any thing about the other crank, & i have all the shells to fit both cranks and rod sets

got my parts from DSS today like christmas again & nearly as costly £165 for this little lot  ,

Den i might have tried that when i was younger and i did'nt know any better

i am missing a part out of my engine that i can only guess was never fitted or stopped being fitted?

it is in the haynes manual and called a oil catchment tray, it does'nt show up in the f1 parts list but shows up in the k0/1/2 parts list and its number is 15621-300-000 anyone have an idea ? cheers mick

[techy5025]

The oil catchment tray is used to feed oil through the final drive gear shaft to the auto chain
oiler. If you plug the shaft under the front sprocket and do your own chain oiling, you shouldn't
need the "tray" part. Someone correct me if I'm wrong on this.

Jim

[mcpuffett]

cheers for that jim, it shows up in the haynes manual but not in the f1 parts list, so that would explain why it was'nt there when i took the motor apart , they stopped fitting it  ,  mick.