Author Topic: Honda CB450 K5 Cafe Racer.. ish  (Read 11829 times)

Offline xb33bsa

  • Posts: 7726
Re: Honda CB450 K5 Cafe Racer.. ish
« Reply #70 on: Nov 01, 2016, 12:38:01 »
First of all.. thanks for your help.  I may still need that rod you have, but in the meanwhile i tried something a little different.

I took out that piece of rod i fabbed and cut it short by 8mm.

Then smoothed out the edge

Since i can't get the pushrod from inside the engine (magnet didn't work) and i know it rotates with the clutch since i turned on the engine and looked inside...

..i just put one 8mm ball inside that hole to minimise friction between the two rods.

It works perfectly  :)

Still... i was getting the same issue with revving whenever i pulled the clutch.  Sure enough, it was the damn clutch cable pushing against the throttle actuator.   
It never did that before.  So weird..
I just found a way of getting it away and now it works fine.

Also.. another spark plug died on me.  It's always the right side plug that dies because the mixture on that side is too rich.

hey you are pretty slick,like i said before the rod is not meant to be spinning with the shaft but it does because it can .it has plenty of clearance to not spin and it is not connected to anything
the only problem with the repair is that you dont have much support for the short piece it looks like it barely goes inside it may work fine but may take out the seal in short order
as far as the plug being sooty it could be ignition related dont assume its mixture until you know the ignition is in good tune
the carb could have a stick slide or a holed diaphram choke plate may be sticking as well

Offline revel.motorcycles

  • Posts: 125
    • Revel Motorcycles Chicago
Re: Honda CB450 K5 Cafe Racer.. ish
« Reply #71 on: Jan 09, 2017, 17:38:06 »
Cool build!

Offline bezugo

  • Posts: 53
Re: Honda CB450 K5 Cafe Racer.. ish
« Reply #72 on: Jan 21, 2017, 16:34:15 »
New update

I was still having trouble with the clutch.  Every time i went for a ride the clutch lever was gaining play just after a few miles.  I even got to the point of almost loosing all travel of the lever and almost didn't get home.

I had to adjust it every single time and the only possibility was that the clutch rod was getting shorter.
Sure enough, it was  >:(

So i pulled it all appart and this is what i found

So it was the sphere between the two rod that was eating them away.  Especially the part that was still the stock rod since that part is aluminum.  If i had known that i wouldn't even had tried what i did.

Now i'm going to replace the whole thing with a single stainless steel rod that i will make myself and while i'm at it, replace the clutch disks aswell.

Anything else i should do while i have it appart?
« Last Edit: Mar 07, 2018, 20:19:22 by bezugo »

Offline bezugo

  • Posts: 53
Re: Honda CB450 K5 Cafe Racer.. ish
« Reply #73 on: Feb 12, 2017, 21:48:17 »
Time for a long awaited improvement.  Both wheels are out and are going to get laced with new spokes and rims.  New tires aswell.

And since the bike will be on a stand for a few days i took the chance to refurbish the front forks with new seals and oil.

The oil that was in there had a bad colour.  I can only imagine how long it was there.

There was also something strange that i only noticed after i had assembled one of the forks..

That little (thick) washer on the bottom of the spring was mounted upside down on both forks.
It didn't look right, but i assembled the first one the same way because thats how it has been for decades.  Luckily i was suspicious and looked for the correct way to do it and had to redo the first one.
« Last Edit: Mar 07, 2018, 20:20:06 by bezugo »

Offline bezugo

  • Posts: 53
Re: Honda CB450 K5 Cafe Racer.. ish
« Reply #74 on: Jul 25, 2017, 15:31:58 »
Hello everyone

Only now i've done a compression test.  I borrowed the tester from a car mechanic and went home to do it.

It read 143 psi on both give or take.  Very similar compression on both cylinders!
Only after i gave the tester back did i remember that the throttle had to be fully open  ::)

What difference should it be with throttle wide open?  More i would think, but how much more.

She was hot and the choke open.

Offline bezugo

  • Posts: 53
Re: Honda CB450 K5 Cafe Racer.. ish
« Reply #75 on: Mar 03, 2018, 14:33:32 »
Its been a while since i posted anything here, but several things were done.

The clutch was sticking bad after the bike got hotter.  After disassembly i noticed the culprit was the clutch basket being scored by the discs and plates.
Both the inner and outer basket were ground and sanded smooth and now it is smoother than ever.

I also painted the engine covers black and polished the stator and oil filter cover.  Looks much cleaner now.

I took apart both carbs again and used an Ultrasonic cleaner to really make sure they were clean.  When assembling i used the stock needle and the stock mixture screw because i have always suspected the ones that came with the rebuild kit (from 4into1) were slightly different.  Also changed the main jet from 145 (stock) to 150 which also came with the kit but have been lost and i recently found them.
New UNI foam filters went where there were cheap pods.

Now the mixture screws actually do something!!  Not sure if it is just because the aftermarket ones are not suited for the bike or if it was due to the ultrasonic cleaning.

The bike idled right away with both throttle flaps completely closed. No need to adjust the idle right away. I did it afterwards just for fine tuning, but before she would never hold idle unless i screwed in the idle screws a couple of turns.

I was feeling very confident that the not revving past 5k rpm was solved, but no :(   It is exactly the same as before.
It pops and almost seems to backfire if i apply full throttle but does not revv any higher.

Im lost.  What now.   Advance?  Bigger jets?

I live at sea level.

Offline bezugo

  • Posts: 53
Re: Honda CB450 K5 Cafe Racer.. ish
« Reply #76 on: Mar 03, 2018, 15:39:26 »
Up until that rpm it runs pretty well.  Strong and smooth.

Offline bezugo

  • Posts: 53
Re: Honda CB450 K5 Cafe Racer.. ish
« Reply #77 on: Mar 07, 2018, 21:35:37 »
New update.

Went over the advance mechanism again and while it seemed to move freely i took it apart, cleaned it and oiled it.
Put it back and she now revs to 8k in neutral. Before she didn't go past 5k even in neutral sputtering when at that rpm.

Went for a drive. She still doesn't go past 5k when in gear. She did once in first gear on a downhill.
Still sputters at 5k.

The clutch pushrod was replaced with a stock one that i got from germany. US postage and import tax makes everything twice as expensive  >:(

I'm running exhausts that are very close to the originals and bought UNI filters (very hard to find in Europe).

The brake master cylinder was replaced by a modern one and the brake line replaced by a steel braided one.

Everything is sorted right now.. except for the high rpms part.
Until 5k rpms the motor pulls strong and smooth at any throttle opening.

« Last Edit: Mar 07, 2018, 21:37:52 by bezugo »