Honda CB450 K5 Cafe Racer.. ish

bezugo

Active Member
First of all let me say i've never owned a proper bike but i am very comfortable with mechanics as i've always worked on my cars and previous bikes.

This bike has been in my garage for the last 34 years. It was my father's.
I remember riding it with him when i was really young. Last time we rode on it i remember my dad saying it was only running on one cylinder. After that it stood there besides his cars for many years. It was then "sold" to a friend of his. The guy never payed my dad so it remained his possession. Three years later his friend died, so his wife called and asked us to go get the bike. That was about four years ago and that's when it became my bike even though it still stood in the garage.
Those were the only three years it was left on a shed. Corrosion came in.

This year i decided i was going to do something about it. 8)

This is how it was

 
I then started to take a few things apart to see if there was any quick fix i could do to get it running.







I soon found out there was a problem with one carburetor and fixed it easily. It was only a broken spring.
Lowered the front headlamp a bit to see how it would look, and yes, that rear tyre was put there by my dad's friend, but i think he never rode it. I'm sure in fact, but we'll see why later on.

Removed the battery as i was sure it needed replacing.
There are also a bunch of parts that are not original, like the rear shocks, the mounts for the headlamp and the handlebars wich were replaced when, 20 plus years ago, a technician at the local Honda shop broke them while moving the bike.
 
After fiddling around for a few days i decided not to do the job on my own as i work as a flight attendant and spend most of my time away.
So i made a few calls and talked to some friends who have modified bikes to find a shop that would do it for me.
The prices and time frames i was given were ridiculous. Sooo expensive!
Even when i only asked them to get it running properly they got greedy.

The decision was made. I would do all of it on my own 8)

Little did i know what was to come :-[
 
It was by finding this forum that i got more confident and got most of my ideas.

This is my biggest inspiration for the build. I'm sure you've seen it before.




How does a bike with that rear wheel clearance ride? It must be really hard :eek:


I was gonna do all sorts of things to it, but them remembered all the work involved and that it would be all up to me.
I also made a decision on the budget for it. I planned on spending around 2/3k euros on it wich would not be a lot since i got the bike for free, but them decided to cut it short by half.
So this will be a budget build. A least for now. Next winter i may take it all apart for proper engine rebuild and powder coating.

At least the tank needs some new color..





It took me so long to get this far :mad:
 
How all of you guys get those classic honda's for free or even bargain prices, I don't know.
But I envy you all.

Love your base for a cafe racer, good luck 8)

CB450 is my personal favorite for brat bike conversion.
 
This is the only thing i haven't done on my own so far.






I also used the apple cider vinegar technique to derust the inside (before it was sent to the painter)

Before any more taking apart and while i waited for several parts to arrive, we (my brother helped) got the bike to run.
It didn't idle properly and was very high in rpms. It had no mufflers or air filters on. Any thoughts on this?
 
After removing the rear section it started to look like the bike i want





And then without mufflers





Looks good 8)
 
After an oil change we started looking for signs of life on the electrics.
The battery was drained and filled with new acid. Tricle charger for a couple of days and it works.
All electrics work properly aside for one dash light and there was no spark from the right spark plug.

Ordered new coils and condenser from DavidSilver and got the engine to run.
That's how I know the other guy never rode it. Dead coil.

I'm not going for an engine rebuild at this point.

Any recommendations?
 
What would cause the engine to rev higher on it's own while idling?

It usually just doesn't idle at all or idles in very low rpms. If i rotate the throttle it revs nicely and sometimes maintains a high engine speed.
It's not the cables. I've checked.

The choke lever doesn't seem to be doing a lot of anything either.
When it revs higher I usually use the choke (open it) and the reaction is slow.
 
Nice bike to start with.

The idle rising could be a vacuum leak, caused between air entering the system between the carbs and inlet rubbers, or between the inlet rubbers and the head.

With the bike running, spray some WD-40 around it and see if the idle rises. If it does, you have a leak.
 
Thanks
I'll check into that. Could it be from the carbs themselves?

Also, just last night I finished installing new front pads.
Is it just me or that support/bracket that tilts side to side is just poorly engineered?
It doesn't allow the pads to make full contact with the disk
 
So... i've rebuilt the carbs again and this time noticed that the spring float valve on the right carb was stuck in open position.
I got it unstuck, cleaned and made sure nothing was clogged, and reassembled both carbs.
This time i used silicone sealant to make sure no air was going in.

I noticed one of the floats had some liquid inside. Not a lot and it did not come out no matter what i did with it.

After putting the carbs back on the bike it started easily. This time i was able to keep it idling at a normal speed.

Took it for a ride and after about 2k or 3k revs it starts misfiring and almost doesn't rev any higher independent of how much throttle i appy.
Even before the ride it was leaking fuel continuously from the right drain. That only stops when i close the petcock.

What could it be this time? Is it the float adjustment? Do i absolutely need rebuild kits for the carbs?
 
Ok.. I adjusted the floats on both carbs and now they don't leak.

It still doesn't rev any higher.

I'm going for a valve adjustment and new points.
Wish me luck
 
This is where I'm at
 

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It bogs. I can make it rev higher if I really give it time to develop.
In neutral it seems like there's nothing wrong. It revs nicely but I never pushed it to redline yet. She's taking her first steps. Don't wanna break anything by reving it like crazy
 
Yea fine tuning the carbs is supposed to be done under load so that's probably why you weren't experiencing anything in neutral. Does it have pods or an aftermarket exhaust?

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