I bought this CB550K3 at Auction

[Nurse Julie]

I own a 550 K3. All that's left of my original bike is the frame and rear hub 😁😁😁😁

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[gbjeppm]

Nice looking bike Julie.

You have the front fender stay

[Nurse Julie]

Nice looking bike Julie.

You have the front fender stay

Yep, that's the nice thing about building a Mongrel, you can fit whatever you fancy or whatever you have laying around😊😊😊

[hondarc166]

the factory that made is about one mile from where i live. they also  made cement mixers in the 60-70 factory now gone supermarket on site now . i agree well made british engineering .

[gbjeppm]

the factory that made is about one mile from where i live. they also  made cement mixers in the 60-70 factory now gone supermarket on site now . i agree well made british engineering .

It will likely last another 100 years if looked after. I am just a sucker for old engineering!!!

Whether it is a Ransomes Lawn Mower, a Myford Lathe,  Fobco Drill, Startrite Bandsaw etc etc.

I guess that is also why I am attracted to the older Honda's as they are built beautifully, and need to be cherished.

[woody928]

This looks like a very familiar story, really nice to see it being brought back to life! 

It's amazing how much can be hiding in places, but really impressive what you can do to bring the chrome back up.

Be sure to have a thorough going over of the wiring, its scary what I've found in places and the honest thing would be to just replace the lot now however that'll be waiting as a future project.

What are your plans for the restoration? Just being mechanically sympathetic and getting it back on the road in good order or more serious ideas?

[gbjeppm]

Plan is to keep it as stock as possible, with original paint etc. That may not be totally possible but we shall see.

Noted on the electrics, but so far mine actually seems to be better than i expected.

[Bryanj]

Decent crimper, not the cheapo insulated terminal type, and the special one if you want to do block connectors plus connectors from vehicle wiring products (doublers and treblers elswhere) plus time and you can refurb a loom to a high standard

[gbjeppm]

Quick update:

She is now running very nicely indeed.

New plugs, cleaned and reset the points,  retimed it, cylinders 2 and 3 were well out. Checked and adjusted all of the valves, and reset the cam chain tension.

Changed the oil and oil filter.

My only observation is that the exhaust is venting quite a lot of water from the pin holes. I am putting this down to me only idling the bike. ( I cant ride it until it has new tyres and the paperwork back from DVLA etc). Any thoughts on this? I am hoping it will stop when I can take  it for a proper ride.

I started to dive into the seat today, and discovered that the floor pan is totally rotten on the edges, so will probably source a new one from DSS.

[philward]

Condensation - thats quite normal when weather is cold - the cause of many rotton exhaust back in the day - to many short rides and winter weather caused this though

[robvangulik]

  retimed it, cylinders 3 and 4 were well out.

How do you do that? It would rather be 1 and 4 or 2 and 3.....

[gbjeppm]

  retimed it, cylinders 3 and 4 were well out.

How do you do that? It would rather be 1 and 4 or 2 and 3.....

Oops, well spotted, i meant 2 and 3, now corrected.

[robvangulik]

 

[gbjeppm]

I have managed to make more progress.

First off I needed to sort out the exhaust, as Muffler No 3 had a couple of holes in it. All of the others were fine, and it seemed a shame to junk it.



I managed to find a local welder who after looking at it said that he could weld in polished stainless, and make it structurally sound. As the holes were underneath, that was fine by me.

The result was much better than I imagined.




So now the exhaust was sorted out, my new seat arrived from Vietnam, and it was ready to ride.

[gbjeppm]

First ride was underwhelming to say the least.

In neutral, the bike was running nicely, idling at 1200, and stable.

Under load, the minute I hit 3500 revs it started to stutter and backfire, it felt like fuel starvation.

I read lots of forum posts, that the bike needs to run a bit rich etc, but no amount of playing with the mixture and idle helped much.

I was trying to narrow down the issue.

I had new plugs, all the leads tested good. I had cleaned the carb, I knew I had fuel, the timing was correct, so i was fairly convinced that the condensers were the problem,

Two new condensers this morning, and wow its a different bike. Idle is better, no stumbling or backfiring all through the rev range. Finally I can ride it without thinking about breaking down