Mike's CB550 Project

[Mike_Berkshire]

Thanks all so far with the help in my initial steps with this project: rebuilding the carbs to get the bike running pre-stripdown, removal of the stuck rocker cover, knocking out the shock mounts from the swinging arm, removal of the steering races and identification of mystery parts along the way. The bike is now stripped down apart from the bottom end which Im intending to leave intact and, so far the wheels are still 'bearings in'. The first outside job of repainting the frame, swinging arm and various other brackets etc should start tomorrow.

Whilst Im waiting for the frame painting I am getting on with the head. All valves etc are out, the head is decarboned and Im now decarboning the valves pre to lapping them in. Whilst working on the inlet valve for #2 cyclinder I can see there is damage/an imperfection in the valve face (see picture). Should this valve be replaced with a new one and if so is it OK to replace one valve only? I have checked piston #2 and there is no sign of any impact damage on the piston. Also there is a single valve collet hiding somehwere on the floor of the shed which Im hoping to find but is so far proving elusive. Thanks, Mike

[McCabe-Thiele (Ted)]

I had a similar damaged valve on my 400 exhaust valve - just the one like you.

I found a good used valve that (Steve at 400fourbits) I did not need to have refaced so it was an inexpensive fix.
I was able to do a normal had grind presumably as it was a standard factory cut valve.

[Bryanj]

PM me your address and i will send you a used one

[Mike_Berkshire]

PM me your address and i will send you a used one

Thank you so much Bryan. I have sent you a PM.

[Mike_Berkshire]

So de-carbonising the inlet valves was easy. The exhaust valves less so. The deposits on the valve face & stem are like concrete. I am assuming this is normal (?) Are there recommended ways of removing the deposits from the exhaust valves? As the crust is so hard Im worried about damaging the valves. I have been using a Dremel clone with softish Scotchbrite mini-mops.

[Bryanj]

Steel wire wheel on bench grinder or in drill and yes it does feel like concrete

[McCabe-Thiele (Ted)]

Call me a vandal - I put my valve in an electric drill using an old screwdriver holding it as a cutting tool. I kept away from the vet edges then finished the job with 400 grit Wet & Dry.

[Mike_Berkshire]

Call me a vandal - I put my valve in an electric drill using an old screwdriver holding it as a cutting tool. I kept away from the vet edges then finished the job with 400 grit Wet & Dry.

That’s quite reassuring Ted. I will continue Dremelling for now then. You don’t say if the bike ran or not after you did this though; I assume it did :-)

[McCabe-Thiele (Ted)]

Call me a vandal - I put my valve in an electric drill using an old screwdriver holding it as a cutting tool. I kept away from the very edges then finished the job with 400 grit Wet & Dry.

That’s quite reassuring Ted. I will continue Dremelling for now then. You don’t say if the bike ran or not after you did this though; I assume it did :-)

Yes it ran and still does - I've used this method for decades on mainly on car engines in the days of leaded petrol.

[Laverda Dave]

Same method I've always used Ted. I use an old electricians screwdriver with a slight radius filled into the edges to prevent any digging in. I go very, very gently on the carbon followed by some wire wool and oil.

[davidcumbria]

Dremel with wire brush worked for me.

[Mike_Berkshire]

Thanks to all the tips on decarbing the valves they are all now cleaned up and shortly i will get to grinding them in on the sparkly clean head. I decided to do some work on the forks next. I read the manual (Haynes) and watched a couple of YouTube tutorials and all seemed fairly straightforward. I followed the steps draining the oil, pre-loosening the bottom Allen screw, removing the top 22mm fap and the spring but, I cannot now get the Allen screw out of the bottom of the fork leg to relase leg form top tube. The bolt just spins around; I assume it screws into the bottom of the damper tube which is rotating with the screw. I have tried pulling on the chrome fork tube, pushing on it to create some tension but no joy. Have I approached this incorrectly or is there a knack to this that I havent discovered? Any advice would be very welcome. Mike

[McCabe-Thiele (Ted)]

Iirc a suitable sized brush stale has been used by members in the past to prevent the rotation. I believe it's inserted down the fork leg to jam the inside part. Never had to do it myself so you might find it via the search facility.

I assume you have removed the spring.

[Mike_Berkshire]

Thanks for the suggestion. The spring is out so will look for a suitable piece of wood and have another go.

[McCabe-Thiele (Ted)]

When I removed mine I used a cordless Impact tool to undo the hex bolt. I did not encounter the turning problem if your is turning sounds as if it should undo with a bit of wedging.