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Discussion Starter · #1 ·
Hey guys,

So my bike is slowly but surely coming along. I decided that I'm gonna dive into the engine rebuild. (I need to turn more wrenches and spend less time grinding)...

I've read the Clymer manual and the real Honda manuals several times and this is not my first engine (but it is my first honda) so I'm not too worried.

Now, I could've sworn that I already had the answers to these questions but I couldn't find them.

What special tools will I need?

Where can I buy the replacement engine "consumables" (bearings, seals, etc.)? I saw the thread on "parts sources" so if that's what works that's where I'll look first.

The engine number is: CB450E-7012***. This makes it a K7 right?

What else should I know or get before I dive in?

Thanks guys. Once I start I'll keep everyone posted as the progress goes on...

Andrea
 

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Re: Gonna dive into the engine...

Yeah, you have a K7.

You'll need an alternator tool and an oil filter tool, both at Motion Pro for less than $10 each.
If you remove the top end, you'll need a cam chain riveter tool - it's easy to break with just a Dremel and punch, but to rivet the cam chain back together you really need a tool.
Other than that, no special stuff.

Get seals and gaskets where you can afford to, for the most part - it's a crap shoot. Many gasket kits don't include valve guide seals or even all the o-rings you need.

Everything you need to know about 450's (almost) is right here on this site......
Fortunately, all 5-speed 450 engines are basically the same critter, that makes it a bit easier.

http://www.motionpro.com/motorcycle/partno/08-0015/


http://www.motionpro.com/motorcycle/partno/08-0027/
 

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Discussion Starter · #4 ·
Re: Gonna dive into the engine...

Thanks TBP. That's exactly what I needed.

Thanks guys.

Andrea
 

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Discussion Starter · #5 ·
Hey guys,

The disassembly has begun... And stopped (more on that later). I figured I'd keep the build progress on here so that if you guys see anything in the pictures that should be looked at or looks broken you can point it out. It's my first Honda twin engine and I received it partially disassembled so having a bunch of extra eyes looking at it will help point out if anything is wrong...

I'm also going to post my questions as I go...

This is the engine as I received it. Everything else was in boxes.



These are the internal parts that were already removed from the engine and head.



The head was pretty much completely disassembled but with all the parts inside.





so I pulled off the head







I finished taking apart the heads and sorting the pieces that were floating around inside.



The sealing surface of the head has a bit of a nasty knick on it. I'm not sure if you can see it in the pictures but it's there. I didn't spend too much time investigating in-depth but I'm hoping it can be fixed with a lapping stone.





First question:

I was able to get the screw off of the top pulley pin but I wasn't able to pull the actual pin. I didn't want to pry it off to avoid damage. Any tricks?



The pistons were already out so the cylinders came off easily. The cylinders walls look good but there's a ring of crust at the top of the cylinder. Also even though the bores look good, there's a pretty big ding on the lip of the cylinder. I was planning on a rebore anyways and even before measuring, with that scratch it looks very necessary.





Opinions?

Next came the oil filter and clutch.

I couldn't get the snap ring that holds the filter cap with my snap ring pliers so I had to get new ones.

I came back with the new pliers and kept going at it.

After getting the very stubborn clip out (it was very very stuck) I tried to get the cap of. After trying to just pull it with the bolt and even pulling straight out with pliers, I realized that the cap was also completely stuck. I made a very simple puller to try and get the cap off.

After I tightened the puller, I felt something breaking loose. Or just breaking.

The cap never even budged. The screw trashed the threads in the cap and I think cracked it. I'm not sure if you can see it in the pictures but one of the four "columns” has two small cracks at the base (where the screw would screw in).





So now what do I do with this cap? Any ideas on how I can remove it? I was thinking of a small slide hammer with some kind of attachment but I also don't want to bash at the end of the crank with a slide hammer...

My other idea was to re-drill and re-tap one size larger and try again.

What do you guys think? Any of you had a very stubborn one of these?

Sorry for the massive post but I want to be somewhat thorough.

Thanks

Andrea
 

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Sensei
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To pull the oil spinner (cap) once you have removed the circlip, you simply screw a bolt in...don't pull the bolt, screw it in and it lifts the spinner out.....
 

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Re: Gonna dive into the engine...

I'm not sure but I think you should have gotten one of the tools Bill suggested a few posts ago and removed that 4 eared nut you're looking at. Then the filter would have come right off.

tbpmusic said:
If that is indeed the case I have the parts you need to fix it from a 73 350G. I'll have to check to make sure it will fit but if it will you can have it for cheap.

Search the forum and you can find the repair manual in pdf format or sources to get the Clymer manual. It can save you a lot of grief and maybe even a few bucks.

Edit: Oops, I misinterpreted the pictures and see you've already got the manuals. What Steve said.
 

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Discussion Starter · #8 ·
Thanks guys,

I have the special tool. I'm stuck one step before I need it.

My screwup was not using the screw to simply pull the cap out. I looked at the parts manual and I thought that using the screww against the part behind it would damage it. Hence my homemade puller.

My puller did essentially the same thing as just the screw except it pulled instead of pushed.

But now the hole is stripped... Since you mention that the screw alone was enough, I'm thinking that drilling and re-tapping might be the best choice here...

Andrea
 

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I'm fairly certain I have a spare 450 oil filter spinner and cup, so just do what you have to, and send me your snail-mail address...... I will expect to be reimbursed for postage....LOL...
BTW, the 350 cup is different...... Steve
 

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newdude said:
First question:

I was able to get the screw off of the top pulley pin but I wasn't able to pull the actual pin. I didn't want to pry it off to avoid damage. Any tricks?
Leave it in there - they hardly ever go bad.
You can easily check it's condition while it's in place - if it spins freely and doesn't feel like it has excess chain wear, leave it.

Yeah, you'll need a bore job, probably valve work too.
You'll also need to get all the rust and crud out of the inside of those knock pins that the cylinder/head studs go through.
Those studs are used as oil passages - the two far right (rider's right) top nuts use copper washers, don't get them mixed up.

I only see one cam in the photos ???
 

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Discussion Starter · #11 ·
Steve, PM sent!

TBP, I do have the other cam it just isn't in the pictures I posted.

About those copper washers... The head hardware was in a baggie. I'll have to go through it and separate them.


Andrea
 

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newdude said:
Steve, PM sent!

TBP, I do have the other cam it just isn't in the pictures I posted.

About those copper washers... The head hardware was in a baggie. I'll have to go through it and separate them.


Andrea
Just a couple of pointers,

First, Get on the web and get a parts book. The manual may tell you what to do, but often does not show you where the bits go. I had this problem with a recently rebuilt engine that i acquired dissembled. Small bits were lost or damaged beyond recognition. This way when you go to assemble the engine you can cross reference the parts break down list with the parts you have. :) It will also tell you the size and length of the bolts requires, wether they are chrome or zinc and if any special washers are fitted etc.

Second, Those copper washers cold work harden (tightening the head nuts against a washer 'works' the metal) so need to be annealed to soften them before fitting, heat them till they're dull red and then let them cool, you can quench them in water, but quenching isn't strictly necessary, the rate of cooling makes no difference to the resulting softness.
 

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Discussion Starter · #13 ·
Hey guys, here's the last couple of days progress...

I went and bought the appropriately sized drill bit to re tap the oil filter cap in order to remove it.



After several failed attempts, the cap was still not moving. So I made a puller using a long tube vise as a slide hammer. I welded up a bolt with some scrap metal to make a small attachment to the cap. I forgot to take pictures of it but it's a simple triangle that "hooked" onto the inside of the cap. I then used the sliding part of the vise to provide the impact.

Again, After several impacts, the cap did not budge. So out came the dremel...





You can't see it in the picture but the rim of the cap has marks from where it was stuck to the filter with corrosion.

After that, everything went smoothly.





When I pulled the oil pump I found a bunch of ground up metal underneath. This picture is AFTER i wiped it with my finger.



Removed the shift spindle.



And then I started started on the main case bolts. Again, check out the corrosion.







Split the cases and here's what I found.













Of course I dropped a bunch of the bearings from the crank and spent a while looking for them. The don't look worn but I'll get to measuring stuff soon enough.

Tomorrow I scrub!!

Andrea
 

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Watch out for those middle bearings when you're carrying around that crankshaft. If/when one of those two races fall off you'll be picking up needles everywhere and they're harder to get together than the end ones.
 

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Hey Mike, what was the tip or technique people were using to keep those center bearings from falling apart on you? I'm sure I remember reading about someone coming up with something clever to shim between the bearings while taking it apart and removing the crank...?


GB :mrgreen:
 

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Anything stuck in between the two races to keep either one of them from moving to far to the center would work. Maybe a piece of of foam on the top and bottom of that gear then taped together would work. Nothing fancy.
 

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Andrea,
Finally dug my way into the shop today (but it's snowing AGAIN)....
I found two examples of the internal spinner, but NO outer cups...
IF the internal part ( the one that is broken in your pix) will suffice, I can send it out tomorrow.... Steve
 

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Discussion Starter · #19 ·
Hey Steve,

The part i trashed is the "cap". I think we are talking about the same thing...

no. 8?






I took apart the tranny today but I have to go get a screw extractor to finish taking off the shift mechanism... Doh.

I'm also fairly certain that this engine was rebuilt at some point in its life and not very well. The sealing surfaces all had enough sealant to clog all the oil passages in the engine. Twice. excess "squeeze-out" everywhere. I also found writing on several pieces.

About the oil splash plate, I read the annotation in TBP's manual about drilling out the plate and using bolts. Anyone ever do this first hand? There is some very serious buildup of crud underneath mine and I'm considering it but I figured I'd check with you guys first.

I'm looking to see if I can find a place nearby to soda blast my cases and stuff but I haven't been lucky. Similarly, does anyone have a recommendation for a machine shop to do the cylinder and head work on this baby in NYC? There's a very big bike shop near me that does alot of vintage stuff so I'm going to go ask them aswell but if anyone has any good experiences I'd love to hear them...

Andrea
 

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I started to drill the plate off mine but stopped just as the bit hit the rivet. What I did instead is to get a coffee pot cleaning brush and bend it in an "L" shape. I then used that along with some solvent to clean under there.
 
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