1978 CB550K Restomod | GTAMotorcycle.com

1978 CB550K Restomod

thirstforspeed

Well-known member
I picked up a non-running (but complete) 78 CB550 a few years ago. I intend it to be my wifes bike when I finish it. What I want to do is rebuild/refresh it, and maybe do a very mild restomod to it.

The plan is to get it to run, then when I can confirm that it doesn't sound like a bucket of rocks in the motor, I will tear it all down and clean/refresh all the parts. Also, I want to repaint the tank, and get rid of the points. I want to make this bike as robust as possible, so no frame or engine mods will be done. It is a really nice bike, so I want to make sure that I keep all the stock parts and frame untouched. I will plasti-dip the wheels and whatnot, but in case my wife doesn't want it, I want to be able to preserve the value to someone who may want to do a real restoration on it. I also have a BNIB 4 into 1 MAC style exhaust that I am going to use the header from, and make my own muffler. My wife said she wants it to be loud, so I will do what I can.

Here it is when I picked it up.






This is what I want it to look like (except different paint and mufflers).

Source
 

thirstforspeed

Well-known member
CB is getting taken apart and carbs getting examined.





Typical Carb grime





I gave up and sent them out to be cleaned and rebuilt. I didn't have the tools (ultrasonic cleaner) to get this much grime off. 70s Cycles in East York did a great job. Tai is a solid dude.




This is what they looked like when I got them back






I polished my clutch cover with a scuff pad, and smoothed out the inside of my intake runners too while they were all off (for different reasons)






You can get an idea of surface finish on this pic. Smoothed is on the right, stock is on the left.
 

Blackfin

Well-known member
Site Supporter
Nice project. Carbs look great.

Um...what's going on with the handlebars?
 

thirstforspeed

Well-known member
the PO slapped a set of clubman bars on it that don't really fit. I have already replaced with a reasonable set of cheapo tracker bars for mock-up purposes.
additionally, everything is only fingertight (also courtesy of the PO) and the levers arent even on correctly. it isnt rideable in this state.
 

Jimsun

Well-known member
I hope you reconsider taking apart the engine. If you cant even do the carbs, which are a lot easier, then don't bother tearing the top end. Itll cost you about $4-500 to redo with stock oem parts. Do a compression test on it and see if the results are within 5% and over 100 psi. If so dont bother touching it. If it however does not turn over then go for it.

Btw how much did the carb cleaning cost and what did it come with
 

thirstforspeed

Well-known member
the engine kicks over fine. totally smooth and whatnot. i want to run it with the fresh carbs just to be sure it doesnt have an issue. if it doesnt, i am not going to take it apart, just clean the outside.
if it does, i will cross that bridge when i get there. thats what winter is for

the rebuild was 160 for parts, and 250 for ultrasonic cleaning and rebuild from 70s Cycles.
 

Jimsun

Well-known member
Ahh thats good that it turns over. Just do the 3k tune up and youll be set. Did tai end up bench syncing the carbs at the very least?
 

Old Suzy

Well-known member
Site Supporter
I could be wrong but I'm betting this bike is still running a points ignition. One of the best updates I did on my old 77 Suzuki was to replace the points with an electronic ignition. I think the cost was well under a $100.00 but completely fixes the pain in the *** adjustment of the points. Also finding good quality points these days is not always that easy.
I agree if you can get away from a complete engine rebuild its the way to go. Would still consider taking the top off to ensure valve clearances are up to spec. and to throw on a new valve cover gasket.
 

Jimsun

Well-known member
^ id go for the points over the dyna-s. They arent hard to do. Matter of fact it takes about 5-10 tops for adjustments.

Valve gap clearance is part of the 3k tune up and doesnt require you to open the whole head cover. There are these tappet covers that takes 17mm and sits right above it for easy valve adjustment access.

To each their own tho.
 

thirstforspeed

Well-known member
yeah, tai bench synced them. and yeah, its still running points. i plan to go with a dyna/hondaman/whatever electronic ignition. i would prefer something like that, but i will see how it runs on the points. if im gonna go thru any effort to get the points up and running, i might as well just put electronic ignition in there.

whatever happens i will do a pressure test and the 3K service. hopefully thats all it needs. i have a feeling it will be. its pretty smooth when i kick it over.

hopefully this weekend i can run it and see.
 

Old Suzy

Well-known member
Site Supporter
^ id go for the points over the dyna-s. They arent hard to do. Matter of fact it takes about 5-10 tops for adjustments.

Valve gap clearance is part of the 3k tune up and doesnt require you to open the whole head cover. There are these tappet covers that takes 17mm and sits right above it for easy valve adjustment access.

To each their own tho.
Agreed points are not that hard to do but in my experience when buying points for these old bikes the quality of the points is questionable. My limited experience is the ratio to of good to bad is like 1 out of 3.
 

Baggsy

Well-known member
Site Supporter
A friend took a couple of years and some cash to get his hands on a decent stock four into four, after he'd converted his into a four into one, on a 750k. It was so loud with the four into one, that I wouldn't ride behind him. If your planning on selling it for a restore, I'd suggest keeping the stock if it's any good.

Nice to see an old bike getting some tlc.
 

TwistedKestrel

King of GTAM
Site Supporter
That 4-into-4 looks to be in pretty good shape. Of course you wouldn't just throw it out, but maybe it'll grow on your wife - old exhausts aren't *that* quiet and MAC exhausts usually look like crap
 

Old Suzy

Well-known member
Site Supporter
A friend took a couple of years and some cash to get his hands on a decent stock four into four, after he'd converted his into a four into one, on a 750k. It was so loud with the four into one, that I wouldn't ride behind him. If your planning on selling it for a restore, I'd suggest keeping the stock if it's any good.

Nice to see an old bike getting some tlc.
Put a 4 into1 set of Vance and Hines pipes on my old GS. Loader than stock but not obnoxious. Love the deep throated growling sound. Looks great too.
 

thirstforspeed

Well-known member
oh yeah, im not going to throw out the 4 into 4s. they are passable, but had been repaired in the past so the lowest pipes on each side have some brazing boogers on them. They still work though.

My plan is to take all of the chrome off the bike (pipes, fenders, covers, headlight doodads, etc) and just store it so that if/when i sell, it will be sold as a complete package unless the buyer doesn't want them. The chrome is in really good shape so I don't want to junk anything.

My wife said that she wants it to be loud, so my plan is to use a 4 into 1 and then build a stainless steel GP style muffler. I have a design that I want to try, and I think it will look good on it, so why not right? If that fails, I will throw the 4 into 4s back on.
 

GateKeeper

Well-known member
the engine kicks over fine. totally smooth and whatnot. i want to run it with the fresh carbs just to be sure it doesnt have an issue. if it doesnt, i am not going to take it apart, just clean the outside.
if it does, i will cross that bridge when i get there. thats what winter is for

the rebuild was 160 for parts, and 250 for ultrasonic cleaning and rebuild from 70s Cycles.
What parts cost 160 bucks ? And 250 for ultrasonic cleaning, I use pine sol and or berryman's and and I get the same result but costs me me about 10 bucks
 

thirstforspeed

Well-known member
the varnish was epic on these things. every single passage was plugged solid. the bike was stored for 3-ish years with an open petcock and 1/4 tank of gas.

I soaked them in pinesol and scrubbed, then in gasoline with another scrub, then gave up and sent them to Tai. 160 was for a full rebuild kit for each carb. i needed new o rings, and new float needles everywhere.
 

Top Bottom