1972 Honda CB450 Cafe/Brat inspired build

Couldn't help it and had to take the top of the engine off so I could finally see the piston damage. Sure enough theres a pretty good hole in the left piston. Took some close up pictures of the valves. Y'all think they are salvageable?

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Left Cylinder Values:

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Right Cylinder Values:

2012-12-09205317.jpg
 
Alright, so I've found a little more time to attach the process of finding out what size my pistons and cylinder sleeves are and what the process of rebuilding is going to entail for my specific motor. Upon further inspection is seems that the left cylinder sleeve has a good bit of gouging in it caused by the piston head that has a hole in it. After borrowing a friends calipers I was able to take a good couple measures of each cylinder.

It is my understanding that the CB450 comes stock with 70mm cylinder sleeves. Mine both measured at ~70.25mm so I'm thinking its safe to say that these have already been bored once. Now a question I have is, should I try to find a set of pistons at .50mm and have the cylinders bored out to 70.50mm? Or should I just go to the 1mm OS pistons and boring? Done a little bit of searching and it seems a little hard to find a pair of pistons in any specific size for my motor. Hopefully it could be easier to find a set in Japan.

Anybody have any input on what size I should try to go to? or where to buy the new pistons/rings.

Photos of gouging.

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I suppose it depends on the depth of the gouges but isn't it possible to hone the cylinders and put a slightly larger set of rings in?
 
johnd900 said:
I suppose it depends on the depth of the gouges but isn't it possible to hone the cylinders and put a slightly larger set of rings in?
Click to expand...

Honestly I don't know the answer to that question. Kinda looking for information still. But the gouges are some good little slivers and it doesn't seem like simply honing would take care of it.
 
Yea, your best bet at this point is to take the cylinders to a machine shop or engine shop (sometimes they're one in the same).
They will take some measurements, and maybe some machine work, and they should be able to let you know how oversize you will have to go.
 
teddpage said:
Yea, your best bet at this point is to take the cylinders to a machine shop or engine shop (sometimes they're one in the same).
They will take some measurements, and maybe some machine work, and they should be able to let you know how oversize you will have to go.
Click to expand...

Damn, I was hoping I would be able to try and pick up a set of pistons and rings while away on vacation. But that does sound like the best idea in any light. I guess next step is to look for a machine shop in town when I get back. Y'all have any good recommendations for where I could find a set of pistons? I've found pretty well all sizes of piston rings on bikebandit but cant seem to get any solid luck on pistons.
 
I ran a set of pistons that looked like those in my KZ1000 a while back.
That was until an ignition problem took out a ring land.
They were stock bore for the 1000, does 70 mm bore with a 17 mm wrist pin sound right.
If that's the case look into Wiseco big bore pistons for the ''73 - '80 KZ900/1000.
 
Okay, I'm reviving my thread from the dead. Finally back home and able to get hands on on the bike. Bought myself an angle grinder and went to town clearing my frame of all the tabs. For some reason I am slightly apprehensive towards cutting the seat hump off, but I'll get to that next.

As far as the pistons are concerned I am going to wait till I get the opinion and work done by a local machinist to see what direction I should be trying to go.

Also looking towards getting an order into dime city so I can start building the motor back up.

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Little bit more work today. There was a lot of metal left where the seat lock was located so I finished grinding it off along with smoothing out some of the factory welds. I also got around to stripping the tank. I was planning on running a bare tank, and may be able to still, but I found I believe three different layers of paint and a little bit of bondo thrown in there. I still need to put quite a bit of love into it but so far I ran through 4 stages of stripping to get all the layers of paint off.

Also, does anyone know if there is a place that I can get a new seal for my existing gas tank cap? An all new cap is $50 on dcc and I'd rather not pay that since all I need is a new rubber seal and latch.

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reesea17 said:
Little bit more work today. There was a lot of metal left where the seat lock was located so I finished grinding it off along with smoothing out some of the factory welds. I also got around to stripping the tank. I was planning on running a bare tank, and may be able to still, but I found I believe three different layers of paint and a little bit of bondo thrown in there. I still need to put quite a bit of love into it but so far I ran through 4 stages of stripping to get all the layers of paint off.

Also, does anyone know if there is a place that I can get a new seal for my existing gas tank cap? An all new cap is $50 on dcc and I'd rather not pay that since all I need is a new rubber seal and latch.
Click to expand...

Part no. 23 on the fiche:

http://www.bikebandit.com/houseofmotorcycles/1972-honda-cb450k5/o/m9199#sch397239

Should be able to walk into a Honda dealer and order it.
 
johnd900 said:
The tank cleaned up nicely.
Click to expand...

Thanks, still needs a good bit of work on it to get the rest of the paint off.

I've got a question about batteries. I'm a little confused at what size battery I will need. I'd like to get as physically small a battery as I can, but I have no idea what to look for past that it needs to be 12V's.

I want to run the following:
Electric starter
Horn
Headlight (Possibly an HID retrofit)
Two bullet size LED taillights
LED license plate lamps

Thats all I can think of right now.. Kinda want to go bare bones on this build.
 
Rich Ard said:
Part no. 23 on the fiche:

http://www.bikebandit.com/houseofmotorcycles/1972-honda-cb450k5/o/m9199#sch397239

Should be able to walk into a Honda dealer and order it.
Click to expand...

Thank you! I hadn't even thought of checking bike bandit yet.
 
Got lots of stuff ordered today, so hopefully I'll be able to start tearing into this motor and making some real progress.

Ingredients:
Carb stainless fasteners
Engine stainless fasteners
Carb rebuild kits
Engine gasket kit
Engine oil seal kit
11" rear shocks
 
Well I started work on the carbs today. Tore them down as much as I could, some of the screws are ceased up so I got them apart as much as possible and have them marinating in pinesol right now.

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Also gave a little go at polishing the points cover. While looking around through peoples builds I have seen that most really like to get a mirror like finish on their polished items, however, I've kinda been toying around with the idea of going for more of a brushed look. Went from 60 grit up to 220 and then finished off with 00 steel wool, theres probably an easier way then using sanding blocks but it worked for me. I like the way it turned out, now if only I could get the rest of the covers off and work on them as well. Gotta take the cylinder sleeves into the machine shop some time this coming week.

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I like brushed too. Everything on my bike was either brushed or black (except for the exhaust).

DSC00238.JPG


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I even brushed my chrome headlight trim
headlight01.jpg
 
Flugtechnik said:
I like brushed too. Everything on my bike was either brushed or black (except for the exhaust).
Click to expand...

How did you go about getting the brushed look on all of your parts?
 
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