Neils 1978 CB550 F2 Project - Newbie Let Loose

[Nurse Julie]

If your brass bits are OEM Keihin, thoroughly clean all the brassware, jets, emulsion tubes etc by removing them, then re use. Fit all new Viton O rings (I stock the kits), re use the top gasket.
Carb cleaner is good but make sure you get it in all the hidden passages. Ideally, an ultrasonic cleaner is best (after removing all the internals) then you can get the entire carb body thoroughly clean. But, if all you have is carb cleaner, use that.

[Neilw]

If your brass bits are OEM Keihin, thoroughly clean all the brassware, jets, emulsion tubes etc by removing them, then re use. Fit all new Viton O rings (I stock the kits), re use the top gasket.
Carb cleaner is good but make sure you get it in all the hidden passages. Ideally, an ultrasonic cleaner is best (after removing all the internals) then you can get the entire carb body thoroughly clean. But, if all you have is carb cleaner, use that.

Thank you. Will I be able to tell if the Brass bits are OEM?

[Nurse Julie]

Yes, the jets will have the Keihin logo stamped on them, it's a letter K that almost looks like a star shape.

[taysidedragon]

If your brass bits are OEM Keihin, thoroughly clean all the brassware, jets, emulsion tubes etc by removing them, then re use. Fit all new Viton O rings (I stock the kits), re use the top gasket.
Carb cleaner is good but make sure you get it in all the hidden passages. Ideally, an ultrasonic cleaner is best (after removing all the internals) then you can get the entire carb body thoroughly clean. But, if all you have is carb cleaner, use that.

What Julie said is good advice, but don't mix up the parts from different carbs. Use a pot or tray for all the parts from each carb.

[Oddjob]

Replace the fuel pipe as well, the old one will most likely be going hard and cracking.

Check the needle clips are in the right slot and the jets are the correct size, you never know who's been tampering with them over the years.

[Neilw]

Quick update.

The bike is completely apart now, and I've discovered a few things.

The steering bearings had been upgraded, but the bottom one had failed - see pic. It was fitted with a spacer, but no seal. I've seen videos where its shown that the seal can foul the bearing when torqued down, so it's got me thinking whether I should just go back to ball and cup?

The rear swing arm is rot underneath, so I've ordered a replacement.

The bottom stem yoke, one of the stop posts, has broken off. Do I replace the whole thing or get someone to weld on a new one? Replacement yoke is only £30.

I've been speaking to Hondaman, and with postage being prohibitively expensive from the US I am going to try to make a new fuse box as per his instructions - wish me luck never done anything like that before!

[Oddjob]

Looks like the bottom race that goes inside the frame was hammered into place and it broke apart as it was fitted. They didn’t come with a seal back in the day, they do now. Up to you which system you replace it with, I prefer tapers but some people have had problems with fitting them and have gone back to ball bearings.

[Sesman]

I had lots of trouble with the taper bearing, eventually reverting to the original ball race solution. Regarding the bottom yoke, be cautious. They are made of cheese and can be easily bent (misaligned). It is possible to realign them, but it’s also very easy to over-stress them doing so. In fact some on this forum may not recommend re truing, but I’d say it really depends on the amount of misalignment…I managed it successfully. If the original bottom yoke is in good condition and has good alignment, try welding and grinding a new stop as a first resort.

[Laverda Dave]

As Ken mentions in his reply that lower taper has been hit with a hammer and was probably like that from the day it was installed!
Speaking as a 400/4 owner I have attempted to fit tapers twice and both ended in failure as a result of not having enough thread showing on the top nut, 1.5 turns in my opinion is dangerous. I went back to ball bearings, much better and I haven't noticed any difference in handling at the speeds we are allowed to travel at in this country as a result of camera's but mostly due to potholes etc!

[Neilw]

As Ken mentions in his reply that lower taper has been hit with a hammer and was probably like that from the day it was installed!
Speaking as a 400/4 owner I have attempted to fit tapers twice and both ended in failure as a result of not having enough thread showing on the top nut, 1.5 turns in my opinion is dangerous. I went back to ball bearings, much better and I haven't noticed any difference in handling at the speeds we are allowed to travel at in this country as a result of camera's but mostly due to potholes etc!

I'm not planning on doing lots of miles or speeds, so I'm looking for the most cost-effective and quickest way to go.

[McCabe-Thiele (Ted)]

In defence of taper roller kits I have found there has been an improvement in the last couple of years. I've had a good experience with Pyramid Parts Kits.

That said I would probably stick with original ball bearings if I have a next time project. My 400 NA Superdream project has been on hold since Wendy's stroke last April. I'm planning to work on the SD again in April/May depending on the weather.👍

Like Ken my own  health is only just returning to a point where work on the bike is possible. I've lost a good three and a half stone in weight since last July, My arm muscles have gone in the process so it's a case of the mind is willing but the body less so. Lol

[SumpMagnet]

Had exactly the same experience as Dave fitting a taper roller kit. The beasrings had hte correct internal and external diameters, but the 'stack' was too tall, and barely any thread was poking through to tighten down the castle nuts.
REverted back to a ball bearing kit which had no issues.

Back in the day, I fitted many a taper roller kit, but for whatever reason, the currently available kits do not seem to have the right dimensions in a lot of cases

[Murf]

I like taper head bearings and feel they are the best so I bought a taper bearing kit for my 550, I had problems fitting it, same as others have said ‘to high not enough thread left at the top’  not protected from elements. I decided original setup had been ok for 50 years so got new bearings and went back to that, everything fits as it should no problems. So my advise,  take the easy path.

[McCabe-Thiele (Ted)]

My 500 already had a taper roller set fitted by the PO, due to water ingress and some standing there was rust on them so I replaced them with a Pyramid set that were the same dimensions (including height). As has been mentioned the bearings stack height needs to be the same or less than the original bearings to avoid thread loss.

[Neilw]

Qucick Update 1st April

been a while since i gave an update.

The bike is now completely dismantled. Discovered that the swing arm was rot, so purchased second hand one from ebay, same for the steering yoke which had some damage, so i replaced that.

The cylinders have been returned, bored out with new pistons and rings.

All engine casings have been prepped for paint - just need some warmer weather before I tackle that.

The frame and other bits are with the powder coater, and I should have them back in a few weeks.

I'm now systematically going through the boxes, cleaning and repairing where needed. Finding other bits that will need paint, which I'll do myself.

I'm now tackling the wiring harness. The bike probably had electrical problems, as many connections were poor or corroded, so cleaned and replaced where necessary.

My major achievement has been building a new fuse box, with ATC/ATO fuses. Issues with extortionate postal charges from the states made it a no-go for Hondaman, so with his direction, I have built my own. Parts cost about £10, so worth a try! For the eagle-eyed, the fuses are not the final rated ones, just what came with the unit.