Winter 2025/2026 Project

[Gary in NJ]

Winter time = Project time.

On the bike operating table is a bike I bought 3 years ago, a 1976 CB550F Super Sport. I've been waiting until I retired to do a full restoration on this bike...and I retired on August 1st. Time to get crackin'.







I bought this bike from an 18-year-old after he had put a few thousand miles on it. I know...sounds like a red flag...probably is. The bike wasn't running right for him so he decided to rebuild the carbs...took them a part...and got in over his head. I met both the young man and his father at his father's garage. Dad is in the heavy equipment business. He wasn't happy about his kid getting a motorcycle...and let him get into the project to see how it went. He assured me that the bike is a runner, but it was running too rich (we will come back to that). According to the title, the kid bought the bike in August 2022 with 2,720 miles, and I got it 2 months later with 5,857. Did he really put 3,137 miles on it in two months? Maybe he rode it a while before it was titled.

Overall the bike is in fair condition. It looks like it was largely garage kept. There is some corrosion on the fork caps and shock bolts. The tank is in good condition as are the side panels (the left is a little warped on the top edge due to what appears to be a fried circuit in the fuse box). It looks like the owner at that time moved the fried circuit to the spare to the right. I'll investigate.



I have been giving the bike some thought for a few weeks, deciding how to tackle a non-running project that I want to do a full restoration. My thought process is to first get it running to see what else needs attention. To that end I got the bike up on my stand and gave it a compression test. Since the bike has sat dormant for years, I figured a wet test would be needed. The factory spec for compression is 170 psi, with an acceptable range of 150-170 with no more than 10 psi varriation. The battery is holding a steady 8VDC...so the kick starter (remember those) came in handy.

Round one: With 10 kicks cylinders 1-3 show between 50 and 54psi. Cylinder #4 shows 53psi..I give it an extra kick and the reading jumps to 75psi. Hmm...I wonder of 1-3 will show a similar improvement with a few additional kicks?

Round two: Cylinders 1-3 show between 75 and 78psi. Cylinder #4 now shows 110psi. I like where this is going.

Round three: Cylinders 1-3 show between 120 and 125psi. Cylinder #4 now shows 148psi. Let's do this one more time....

Round four: Cylinders 1-4 show between 152 and 155psi. No need for a wet test. I'm in range with a stone-cold engine.

About the spark plugs I removed for the compression test; I can see why father and son suspected it was running rich...



This bike has an open exhaust...no muffler at all (check the top photo)...so yeah with stock jetting those plugs don't surprise me. The reason it has no muffler - someone decided to modify the exhaust...but they cut the pipes BEFORE the collector. They realized their mistake and tried to fix the problem with muffler wrap. So yeah, that's a cluster *uck. One of the unique things about the 550F is the header pipes...they wrap around beautifully into a 4-into-1 collector. An aftermarket exhaust isn't an option for this project, but luckily I've had three years to check eBay and sometime ago scored a 550F in very good condition for $25.

So the other thing I have to do to get this bike started is to rebuild the carbs. When I got the bike I received an assembled carb bank, and a bag of removed parts. The bag of parts looks complete, but I've ordered a carb kit because I have no idea the condition of the brass and all of the rubber is dry (o-rings and boots/isolators). I now have the carbs completely disassembled and ready to go through my Vapor Blaster and Ultrasonic cleaner.







Stock jetting is Keihin 100 main & 45 pilot jets. The jets that were last installed appear to be from a Keyster rebuild kit...likely what I've ordered. Keyster kits are good...but I may buy Keihin brass and not use the jets in the kits.

Hopefully I have the bike running in a few weeks. I have a new battery on order, and by the time I get the carb rebuild parts I should have everything cleaned and stagged for reassembly. I'm hoping the engine runs well...but if not I'll fix what is needed. I'd rather not rebuild the engine... I do plan on painting the engine...so if I have to rebuild the engine it does make painting a lot easier. We'll see.

 

[Motogiro]

Man! I love these projects!

 

[TownsendsFJR1300]

How bout putting together a 1975 RD 350 , in orange for me??

Seriously...

 

[grcamna7]

Nice CB550F Gary !
I hope you bring it back to original,as it's a wonderful classic.
The original fuse box can be improved by replacing it with a 'much improved' blade-type.
There's a site: sohc4.net that's very good and a guy on there(member name 'HondaMan')who has printed a book which gives Much information on the 550's.
He also has the improved fuse box.

 

[grcamna7]

Winter time = Project time.

On the bike operating table is a bike I bought 3 years ago, a 1976 CB550F Super Sport. I've been waiting until I retired to do a full restoration on this bike...and I retired on August 1st. Time to get crackin'.

View attachment 93745

View attachment 93746

View attachment 93747

I bought this bike from an 18-year-old after he had put a few thousand miles on it. I know...sounds like a red flag...probably is. The bike wasn't running right for him so he decided to rebuild the carbs...took them a part...and got in over his head. I met both the young man and his father at his father's garage. Dad is in the heavy equipment business. He wasn't happy about his kid getting a motorcycle...and let him get into the project to see how it went. He assured me that the bike is a runner, but it was running too rich (we will come back to that). According to the title, the kid bought the bike in August 2022 with 2,720 miles, and I got it 2 months later with 5,857. Did he really put 3,137 miles on it in two months? Maybe he rode it a while before it was titled.

Overall the bike is in fair condition. It looks like it was largely garage kept. There is some corrosion on the fork caps and shock bolts. The tank is in good condition as are the side panels (the left is a little warped on the top edge due to what appears to be a fried circuit in the fuse box). It looks like the owner at that time moved the fried circuit to the spare to the right. I'll investigate.

View attachment 93748

I have been giving the bike some thought for a few weeks, deciding how to tackle a non-running project that I want to do a full restoration. My thought process is to first get it running to see what else needs attention. To that end I got the bike up on my stand and gave it a compression test. Since the bike has sat dormant for years, I figured a wet test would be needed. The factory spec for compression is 170 psi, with an acceptable range of 150-170 with no more than 10 psi varriation. The battery is holding a steady 8VDC...so the kick starter (remember those) came in handy.

Round one: With 10 kicks cylinders 1-3 show between 50 and 54psi. Cylinder #4 shows 53psi..I give it an extra kick and the reading jumps to 75psi. Hmm...I wonder of 1-3 will show a similar improvement with a few additional kicks?

Round two: Cylinders 1-3 show between 75 and 78psi. Cylinder #4 now shows 110psi. I like where this is going.

Round three: Cylinders 1-3 show between 120 and 125psi. Cylinder #4 now shows 148psi. Let's do this one more time....

Round four: Cylinders 1-4 show between 152 and 155psi. No need for a wet test. I'm in range with a stone-cold engine.

About the spark plugs I removed for the compression test; I can see why father and son suspected it was running rich...

View attachment 93749

This bike has an open exhaust...no muffler at all (check the top photo)...so yeah with stock jetting those plugs don't surprise me. The reason it has no muffler - someone decided to modify the exhaust...but they cut the pipes BEFORE the collector. They realized their mistake and tried to fix the problem with muffler wrap. So yeah, that's a cluster *uck. One of the unique things about the 550F is the header pipes...they wrap around beautifully into a 4-into-1 collector. An aftermarket exhaust isn't an option for this project, but luckily I've had three years to check eBay and sometime ago scored a 550F in very good condition for $25.

So the other thing I have to do to get this bike started is to rebuild the carbs. When I got the bike I received an assembled carb bank, and a bag of removed parts. The bag of parts looks complete, but I've ordered a carb kit because I have no idea the condition of the brass and all of the rubber is dry (o-rings and boots/isolators). I now have the carbs completely disassembled and ready to go through my Vapor Blaster and Ultrasonic cleaner.

View attachment 93750

View attachment 93751

View attachment 93752

Stock jetting is Keihin 100 main & 45 pilot jets. The jets that were last installed appear to be from a Keyster rebuild kit...likely what I've ordered. Keyster kits are good...but I may buy Keihin brass and not use the jets in the kits.

Hopefully I have the bike running in a few weeks. I have a new battery on order, and by the time I get the carb rebuild parts I should have everything cleaned and stagged for reassembly. I'm hoping the engine runs well...but if not I'll fix what is needed. I'd rather not rebuild the engine... I do plan on painting the engine...so if I have to rebuild the engine it does make painting a lot easier. We'll see.

I like your idea of original Keihin brass

 

[Gary in NJ]

Boy oh boy do I hate waiting for parts. Especially when it's four little $3 parts. I used a 4into1 carb kit which is very complete and has a good reputation. I used one of their kits on my CB900 and it worked great. While I waited for that to arrive (just 3 days) I vapor blasted the carb bodies and gave them a warm bath in the ultrasonic. Unfortunately, I forgot to remove the little felt dust seals on the carb body where the slide shafts go through the upper body (they looked like grease on carbs 1 & 2), so they were lost to a stream of water and glass beads. I only realized my mistake on carb #3. They needed to be replaced anyway because there was not much left of them. The internet says to make your own from hobby-shop felt...but since I never saw what good seals should look like, I thought it wise to buy new ones. They took 13 days to arrive.

While I waited (for what I thought would be 3-4 days) I figured I'd address an issue the PO pointed out - a leaking shift shaft. When I removed the side cover to gain access to the seal about a pint of oil poured out from behind the cover - not what I was expecting - it should be dry. It wasn't the shift shaft that was leaking - it was the oil pump. If you look at the photo you can see that the oil pump resides in its own chamber. A quick inspection revealed 3 o-rings that turned into plastic allowing oil to leak out.



The shift shaft seal may still need to be replaced...and I'll probably replace that and the main shaft seal since they could be 50 years old.

As I continued to wait for parts I tried to figure out my plan for the restoration. I really want to paint the engine. But painting a fully assembled engine 1) never looks good, and 2) is a pain in the ass because you are wrestling with a 160 pound hunk of metal. My thought for now is; assuming it runs well and doesn't make horrible sounds, I will remove the top end and replace the valve guides, clean up the combustion chambers and lap the valves. This will allow me to replace the base and head gaskets so I won't have to worry about them down the road. This also allows me to paint the head, cylinder bank and lower-end separately - giving it a better (factory) finish. I will vapor blast the generator, points, clutch and left side covers.

I cleaned up those dirty spark plugs and checked the ignition system. I got a nice strong spark from the points-based ignition system. I also decided to go through the box of parts that came with the bike. To my surprise, I have every OEM part that was removed from this bike. Original rear fender/light, seat and some other odds and ends. What I don't have though is the original speedometer. How do I know you ask?

From my first post above I noted that I thought that the mileage shown on the bike is strange. The bike doesn't present as a machine with just 5,800 miles on the odometer (but it does present as garage kept). Well, when I found the OEM seat I decided to open the document compartment. In there I found insurance and registration cards from an owner that had the bike from 2015 to 2020. Also among the aforementioned cards is a receipt from the shop that took care of the registration process...possibly the dealer. Take a look at the top of the document - at the top is written 20,521. Now look at the title...it notes the mileage as 27200. Given that the odometer shows 5,857 I assumed that it was 2,700.0...nope it's 27,200.





Oh well. The bike has somewhere around 30,000 miles...and that makes sense.

I received the 4 felt washers yesterday and did the final assembly and bench sync on the carbs. Before and after photos below:







This morning after I had my coffee I lubed the front of the carb bank with some silicone spray, heated the boots/isolators with a heat gun, and stuck the carbs into place. I drained 3+ year-old gas from the tank (it was clean...and the inside of this tank is pristine) and installed the tank back on the bike.

She fired right up.

 

[grcamna7]

Boy oh boy do I hate waiting for parts. Especially when it's four little $3 parts. I used a 4into1 carb kit which is very complete and has a good reputation. I used one of their kits on my CB900 and it worked great. While I waited for that to arrive (just 3 days) I vapor blasted the carb bodies and gave them a warm bath in the ultrasonic. Unfortunately, I forgot to remove the little felt dust seals on the carb body where the slide shafts go through the upper body (they looked like grease on carbs 1 & 2), so they were lost to a stream of water and glass beads. I only realized my mistake on carb #3. They needed to be replaced anyway because there was not much left of them. The internet says to make your own from hobby-shop felt...but since I never saw what good seals should look like, I thought it wise to buy new ones. They took 13 days to arrive.

While I waited (for what I thought would be 3-4 days) I figured I'd address an issue the PO pointed out - a leaking shift shaft. When I removed the side cover to gain access to the seal about a pint of oil poured out from behind the cover - not what I was expecting - it should be dry. It wasn't the shift shaft that was leaking - it was the oil pump. If you look at the photo you can see that the oil pump resides in its own chamber. A quick inspection revealed 3 o-rings that turned into plastic allowing oil to leak out.

View attachment 93754

The shift shaft seal may still need to be replaced...and I'll probably replace that and the main shaft seal since they could be 50 years old.

As I continued to wait for parts I tried to figure out my plan for the restoration. I really want to paint the engine. But painting a fully assembled engine 1) never looks good, and 2) is a pain in the ass because you are wrestling with a 160 pound hunk of metal. My thought for now is; assuming it runs well and doesn't make horrible sounds, I will remove the top end and replace the valve guides, clean up the combustion chambers and lap the valves. This will allow me to replace the base and head gaskets so I won't have to worry about them down the road. This also allows me to paint the head, cylinder bank and lower-end separately - giving it a better (factory) finish. I will vapor blast the generator, points, clutch and left side covers.

I cleaned up those dirty spark plugs and checked the ignition system. I got a nice strong spark from the points-based ignition system. I also decided to go through the box of parts that came with the bike. To my surprise, I have every OEM part that was removed from this bike. Original rear fender/light, seat and some other odds and ends. What I don't have though is the original speedometer. How do I know you ask?

From my first post above I noted that I thought that the mileage shown on the bike is strange. The bike doesn't present as a machine with just 5,800 miles on the odometer (but it does present as garage kept). Well, when I found the OEM seat I decided to open the document compartment. In there I found insurance and registration cards from an owner that had the bike from 2015 to 2020. Also among the aforementioned cards is a receipt from the shop that took care of the registration process...possibly the dealer. Take a look at the top of the document - at the top is written 20,521. Now look at the title...it notes the mileage as 27200. Given that the odometer shows 5,857 I assumed that it was 2,700.0...nope it's 27,200.

View attachment 93755

View attachment 93756

Oh well. The bike has somewhere around 30,000 miles...and that makes sense.

I received the 4 felt washers yesterday and did the final assembly and bench sync on the carbs. Before and after photos below:

View attachment 93757

View attachment 93758

View attachment 93759

This morning after I had my coffee I lubed the front of the carb bank with some silicone spray, heated the boots/isolators with a heat gun, and stuck the carbs into place. I drained 3+ year-old gas from the tank (it was clean...and the inside of this tank is pristine) and installed the tank back on the bike.

She fired right up.

Very good progress Gary.

I've been looking for an original 'barn find' 1976' CB550K,with the 4 into 4 pipes.

 

[trepetti]

Wow. How I wish I had the time and environment to do work like this. Then all I would need would be the talent. Someone once said that "...two out of three aint bad."

 

[Motogiro]

I'm not familiar with the 4 into 1 carb kit.

 

[Gary in NJ]

4into1 is the supplier

Ultimate Carburetor Repair Kit - Honda CB550F Super Sport

Ultimate carburetor repair or rebuild kit for the Honda CB550F Super Sport. This kit comes with a shaped float bowl gasket made of high quality Viton rubber so it will not swell after coming in contact with fuel.

4into1.com

 

[Motogiro]

I was imagining the carbs mounted to a plenum! LOL!
Nice kit!