Topic: Re: CB550 Cafe Racer "Four Claws" Build (Re-jetting Progress, a few questions)

[Elniniomuchachos]

I've got the 77 46A PD's on my 550.  One thing to check on these is the air hole that supplies atmospheric air pressue to the float bowls.  There is one on each carb.  They are not filtered, and if these get partially blocked it will cause jetting issues.  It is a poor design, and Honda changed it with the 46C's to a single air line, and joined the others together.

Yeah I'm running the 46C's. The 77 bike I got came with these. I've cleaned the carbs 4 times already, with cleaners, guitar strings, compressed air, gasoline. I've triple checked the float height, and they're all set to 14mm (though I've read that the 46C's are supposed to be at 12mm???. But I've also read that some people never noticed a difference between the two float heights.) I'm going to work on getting the leaks taken care of, along with getting the timing dead on and the front brakes finished up before I move on with the jetting.

Another thing I noticed when I did my ride around was that it would backfire every so often, and it was extremely loud. It didn't sound like it was coming from the carb, but more like the exhaust.

On the next oil change I am going to be adding a oil pressure gauge, (maybe a temp gauge as well, if I can find a two in one.) Since I'm not running the idiot lights.

Any good clues on what is causing this damn petcock leak? It's a "new" to me petcock that I picked up at the local graveyard, not sure which bike it's off of, but it looks just like the 76 550 petcock except the spigots go out sideways instead of pointing down. It's a Keihin, and is leaking out of the front faceplate.

[Tintop]

I'm not sure there are rebuild kits for that style petcock.  I got a new one off eBay for my build, similar style with a single horizontal outlet.

[bonhomechristopher]

Nice!!  I got my bike up and running but only put about 130 miles on it before I had to leave it behind to go to school.  I will try to pick it up over fall break.  I have done the no license, no insurance, no tag thing, but I made sure I had a front brake because I don't want to die!!

[RAWNOG]

 Nice bike, I have a 75 cb550k that Im still working on. I cant figure out why my carb valves wont stay in synch when i pull the throttle, so Im also about to rebuild the carbs... again.
 Hey, I have a basic question about the starter switch on a 76 right hand control. Will it work on my 75 wiring harness? it seems all the wires from the switch match up in the headlight bucket except theres a blk/red that i cant find. looking at the diagram, it seems the brwn/red(coming from fuse box) is the harness wire i should connect to.?

[Elniniomuchachos]

Nice bike, I have a 75 cb550k that Im still working on. I cant figure out why my carb valves wont stay in synch when i pull the throttle, so Im also about to rebuild the carbs... again.
 Hey, I have a basic question about the starter switch on a 76 right hand control. Will it work on my 75 wiring harness? it seems all the wires from the switch match up in the headlight bucket except theres a blk/red that i cant find. looking at the diagram, it seems the brwn/red(coming from fuse box) is the harness wire i should connect to.?

it sounds like the nut that locks down the throttle slide to the throttle linkage may be loose? But don't take my word for it... I'm still fiddling with carb problems my self. I'm not really sure about the wiring harness interchangeability. I built my own simplified wiring harness, and don't have any bar switches. Have you looked up the differences between the wiring harnesses? I know the manual has the full diagram of them. Maybe that would be a good place to start? 

[Elniniomuchachos]

Just an update : Tonight I finally picked up a timing light. Just the default 40 dollar Auto-zone one. Went to check everything - points gap is good. start it up... sounds completely different. Why? Because it was only running on 2-3. Check the wiring to the coils, it's all good. I figured the coils are good because it was running alright the other day. So I check the points and condensers. Take a 12v lightbulb with a wire grounded to the engine and another going to the 1-4 points. Move the crank to 1-4 Fire mark. Nothing... Do the same with the 2-3, the bulb lights up. Just out of curiosity I take a condenser off another engine I have laying around, mount it all up, and check spark. Good. Start it up and sounds great. so I got that taken care of. Used a Dwell/Tach meter to check the correct setting points timing. It was right on 40 for both.
I still need to actually check the timing with the light, but my grandfather is going to show me how to do it perfect tomorrow maybe. He used to have a 77 CB750, and has worked on cars his whole life.
Once I get the timing perfect, I'm going to sync the carburetors.

In a previous post I mentioned what I have been doing for the Carbs with the pod filters. Right now I have the 97.5 mains in. The Needle in the top notch (leanest).

I took it around the block this evening and the thing hauls now.That old 1-4 condenser was holding back engine power. After a run at full throttle in 3rd gear I came home and took out the plugs. They look pretty good to my knowledge. A nice tan/brown on the tips, but with a little black. I think the black is some old stuff from when I had it running extremely rich.

Here's a pic of the plugs.

http://www.flickr.com/photos/58837550@N02/6129671762/#


I will do more runs after I get the timing perfect and the carbs totally synced. But I think I have the Main jets set.

[RAWNOG]

 Nice Im loving this thread, and you were right about the carbs.

slide to the throttle linkage may be loose?

-The hex that holds it together with the weird washer was a little loose.

[Elniniomuchachos]

I also finished up the front brakes the other day. But my master cylinder is leaking from the piston where the lever is. I also think that the stock master cylinder is too weak to power the dual discs. There is a lot of play and at speed the brakes just do not feel adequate. I'm thinking I'll use it for a while, but will keep my eye out for a good deal on either a modern or a decent goldwing MC.

[Elniniomuchachos]

So I finally finished the bike and have been riding it to school and what not. And what happens? On the way home from school last night the engine starts making this strange tapping like I've never heard before, and then BOOM! My number 4 piston blows up... Looks like something happened with the intake valve and it penetrated the piston.
I'm pretty much over this... I have a spare engine that I hope will work. If the spare works and runs well with no obnoxious leaks, I will run it, if not I don't know what the hell I am going to do.
While using the spare I may have the ruined engine professionally rebuilt. Maybe with some mods.
This is pretty pathetic in my opinion. I rode the bike for about a week, just within 15 miles of my house along with a couple short highway rides.

Is this bike cursed or am I?

[Tews19]

the engine was recently rebuilt by professions? Um if so, bring it to them and ask WTF

[Elniniomuchachos]

the engine was recently rebuilt by professions? Um if so, bring it to them and ask WTF

No, I did all of the work on the engine. All I did was new gaskets. I'm not sure what the hell went wrong, but something caused that intake valve to get screwed. I took out the spark plug for number 4 and I can see the intake valve moving way far down.