Maraakate
Veteran Member
Got a call yesterday from a younger fellow who wanted me to go over his 78 CB400T1 and basically do the standard tune-up, replace what needs replaced, and rebuild the front forks because the right side is leaking.
It's drivable and he did drive it over to my house and followed his girlfriend in her car. Very nice shape. I really like the headlight fairing, which I believe may be a Hondaline one? Unsure, but fits the aesthetic very well and I really don't like fairings for the most part.


The tune-up is going to be valve clearances, cam chain adjustment, lube and adjust cables, adjust clutch, lube pivots points, grease swingarm, oil change, carb sync and pilot mixture adjustment, drive chain lube and adjustment, nip back spark plug wire and rethread spark plug caps, new spark plugs, and balancer chain adjustment.
After he left, I took it for a test drive, and I noticed the head seemed fairly loud. Not as bad as when one of the tapped adjusters are loose. I set the cam chain tension, and it immediately went away. Required about 3 or 4 full turns until it deployed. At 18,000 miles on this bike, it appears it was never done before. Otherwise, it ran quite well. Front brakes are a bit squeaky, and the tires were replaced before. The tires were also close to being flat (like less than 10psi). I noticed this before he left and mentioned that it may be an issue, but we'll see how much it air it loses over the next week. I filled the tires up and tightened the valve stem cores just in case if they were a bit leaky. With the squeaky front brakes and the front end needs to come off anyways I'll take the brakes apart to clean it up in there and make sure the front brakes aren't completely glazed over. Usually, when I run into that problem some 120 sandpaper and it's good to go.
So, the first thing I noticed and pointed out to him is that the intake clamps are not original. It may not be an issue but could be and just wanted to note this to him. Luckily, it does not seem to be an issue.

Not as much pictures for these builds as I'm kind of repeating myself. I went to do a compression check, which is a lot harder because no electric start! ~155PSI on both sides. Pretty good. As I was pulling the plugs I noticed D7EAs.

The left side had some helicoil done to it in the past.

We already agreed about ordering a new air filter as he was unsure about it. I found two air filter stacked on each other and not oiled.

The bottom one was in decent shape so I oiled it. It's good enough for doing test rides. I also noticed the drain plugs were never serviced before. I pulled those plugs and of course a lot of nasty crap came out.

Drive chain has 4 inches of slack. It's toast. HOWEVER, he did have a brand new DID 530-100L chain from the PO that was never installed so I will be cleaning that up today and installing it. I also checked the swingarm and amazingly it pumped grease. Very lucky on his part. Kickstand was very, very tight. A lot of degreaser, working it back and forth, and finally got some nice action. Then I lubed it a bit and works great. I did the same for all the pivot points like the foot pegs and kickstart lever.
I did the valves, and the intakes were within spec, but on the tight end of it. Reset them. New valve cover gasket, etc. It needed the valve cover gasket as it was leaking quite bad and he originally was wanting a quote for head gasket replacement, but I said it's probably just the valve cover but let's see what we got going on. Another victory for the owner.
So far, so good. A few small quirks, but otherwise a nice tune-up. Fun precursor to the CM400E and was mostly kept in good shape.
It's drivable and he did drive it over to my house and followed his girlfriend in her car. Very nice shape. I really like the headlight fairing, which I believe may be a Hondaline one? Unsure, but fits the aesthetic very well and I really don't like fairings for the most part.


The tune-up is going to be valve clearances, cam chain adjustment, lube and adjust cables, adjust clutch, lube pivots points, grease swingarm, oil change, carb sync and pilot mixture adjustment, drive chain lube and adjustment, nip back spark plug wire and rethread spark plug caps, new spark plugs, and balancer chain adjustment.
After he left, I took it for a test drive, and I noticed the head seemed fairly loud. Not as bad as when one of the tapped adjusters are loose. I set the cam chain tension, and it immediately went away. Required about 3 or 4 full turns until it deployed. At 18,000 miles on this bike, it appears it was never done before. Otherwise, it ran quite well. Front brakes are a bit squeaky, and the tires were replaced before. The tires were also close to being flat (like less than 10psi). I noticed this before he left and mentioned that it may be an issue, but we'll see how much it air it loses over the next week. I filled the tires up and tightened the valve stem cores just in case if they were a bit leaky. With the squeaky front brakes and the front end needs to come off anyways I'll take the brakes apart to clean it up in there and make sure the front brakes aren't completely glazed over. Usually, when I run into that problem some 120 sandpaper and it's good to go.
So, the first thing I noticed and pointed out to him is that the intake clamps are not original. It may not be an issue but could be and just wanted to note this to him. Luckily, it does not seem to be an issue.

Not as much pictures for these builds as I'm kind of repeating myself. I went to do a compression check, which is a lot harder because no electric start! ~155PSI on both sides. Pretty good. As I was pulling the plugs I noticed D7EAs.

The left side had some helicoil done to it in the past.

We already agreed about ordering a new air filter as he was unsure about it. I found two air filter stacked on each other and not oiled.

The bottom one was in decent shape so I oiled it. It's good enough for doing test rides. I also noticed the drain plugs were never serviced before. I pulled those plugs and of course a lot of nasty crap came out.

Drive chain has 4 inches of slack. It's toast. HOWEVER, he did have a brand new DID 530-100L chain from the PO that was never installed so I will be cleaning that up today and installing it. I also checked the swingarm and amazingly it pumped grease. Very lucky on his part. Kickstand was very, very tight. A lot of degreaser, working it back and forth, and finally got some nice action. Then I lubed it a bit and works great. I did the same for all the pivot points like the foot pegs and kickstart lever.
I did the valves, and the intakes were within spec, but on the tight end of it. Reset them. New valve cover gasket, etc. It needed the valve cover gasket as it was leaking quite bad and he originally was wanting a quote for head gasket replacement, but I said it's probably just the valve cover but let's see what we got going on. Another victory for the owner.
So far, so good. A few small quirks, but otherwise a nice tune-up. Fun precursor to the CM400E and was mostly kept in good shape.







































































