Topic: 1977 CB550F Pods replacement

[MLW9110]

This is a subject that has been beat to death on this forum and others but I wanted to ask about problems I'm having with my 1977 CB550F.

I bought the bike a couple of months ago as a running/riding project. It didn't run very well and needed some fiddling to get it to run ok. It had sat for a long time. I thought I had lucked out and wouldn't have to rebuild the carbs. It was hard to start when cold but once it warmed up it wash't bad. I rode it and enjoyed it but it would occasionally run rough and then be ok. The more I rode it, the worse it got. So, I rebuilt the carbs. After the rebuild, it was still hard to start. Once I got it running and warmed I was able to vacuum balance the carbs and the engine ran pretty good above idle. I have not ridden the bike since I balanced the carbs. (It's raining).

Here's what I'm working with.
Bike is rough cosmetically. It sat out in the rain a lot I think.
Has Unifilter cylindrical foam filter pods. Airbox has been removed and previous owner didn't have it.
I've adjusted the valve clearances, changed the oil and filter, replaced points and condensers.
A solid state regulator/rectifier is installed.
4 into 1 headers appear to be original but muffler is not.
At idle, the carbs "pop" fairly regularly. Adjusting the mixture screws doesn't seem to do anything.

My intent was to make it a basic rider. I'm thinking that I want to put a stock airbox in but it's not easy to find the parts.
Nothing I'm finding on eBay is complete and I can't be sure about compatibility of the 1977 air box with the ones I see available.

So, how can I make this bike run better? Is there a recommended set of velocity stacks or pods that will help? From what I'm reading, rejetting without addressing the intake flow is pointless.

Mike
Bremerton, WA USA

[RAFster122s]

Little more information needed to help...
Which model carbs? The number stamped into the side of the carbs will answer this question.
If it has the stock carbs they are an extremely lean burning design and your running issues are likely attributed to this. They are known to foul with deposits easily as well and do not like to sit idle. Overall, too many curse these carbs even when using the stock air box.
Since the air intake manifold spacing was not modified they can be replaced with the earlier carb set if you wish to spend the money finding a set, but let's get some info so we can help sort some of what is there.
Are the filters uni brand or otherwise? A few photos could help.
Lean pops while running aren't surprising to me with the stock carbs.
I don't think I am going to be able to guide you far but others will need the info I am asking for as well

What plugs are you running and whose solid state rectifier & regulator did you put on it?
Presuming you are running regular octane fuel. Is it oxygenated or alcohol free?
Where did you buy your points and condensers? The Chinese Diachi brand are awful and many times the condensers fail quickly or are junk out of the box... Fwiw and extremely difficult to impossible to get to adjust #2&3 points. You don't mention issues with them so you likely sourced them from a good source.
How tight do you have your valves set? What measurement for intake and exhaust?
Are your plug caps replaced? When you remove them from the wires and test their ohms what reading do you get? You should trim about 1/4 off the ends of the wire before you screw them back on.

Welcome to the forums and your cb550 ownership...
David

[jonda500]

David, AFAIK the stock carb set on this model is NOT the dreaded cursed PD's, they are the same on all F models. So any airbox and associated parts will fit except the 77/78 K one! (I am 95% sure, someone will correct me if I am wrong!)
John

[RAFster122s]

Good, then we aren't dealing with the nightmare carbs...

[scottly]

Once I got it running and warmed I was able to vacuum balance the carbs and the engine ran pretty good above idle. I have not ridden the bike since I balanced the carbs. (It's raining).

Mike, you really should ride the bike a bit after the work you've done, and then re-evaluate what needs to be addressed. The Uni foam filters are better than some "pods" that have a 3/4" wide ring of filter area.
When you replaced the points, did you check the ignition timing?

[HondaMan]

Like he said ^^^: ride it for a while. It is very common for those valves which sat open all those years to get a bit of rust on their open faces, which will make it pop back toward the intake. The first cure of that is to ride it for at least 100 miles (or else pull the head to fix the valves directly, but that's a whole big can of worms to open...). In all but the CB650 engine, the valves tend to clean themselves when run. Adding a couple of ounces of oil (any oil) to the gas tank will also help to loosen up the piston rings, which are also likely kind of sticky (like the valve stems).

[bryanj]

You can even use the 500 airbox assembly as the only difference is that the 500 does not have the oil vapour recirc from rockerbox

[MLW9110]

David, thanks for your response. Here's the answers to your questions.

Carbs are 069A.
Plugs are new. NGK D7EA
Regular oxygenated gas. Fresh.
Points and condensors came from 4into1. Mfg unlnown.
Carb kits also from 4into1.  Kit had bowl seals that were shaped to fit the bowls.
Valve clearances were set to spec.
Plug caps were replaced. The old ones were definitely bad.

[MLW9110]

Scottly, thanks for your response.
I have only timed it statically. Next time I work on it I'll check it with a timing light.

[MLW9110]

The new jets and needle are stock and the same as the ones removed.

[HondaMan]

If you still have the old points plate, replace the present condensors from 4into1 with the old ones. The ones from 4into1 are garbage (that's the most polite word I can think of to describe them...). They alone can cause the bike to run poorly, pop & backfire, and not run at all shortly.

[denward17]

Are the old jets and needles the original ones? (Keihin)

If so, you may be better off cleaning and re-using them than whatever you got from 4into1.

[MLW9110]

I don’t know if the removed jets and needles were original. I doubt it.

I'm pretty sure the old condensers were bad. I was getting a lot of sparking on the old points. Is anyone selling decent new condensers?

The solid state regulator rectifier was on the bike when I bought it. Mfg unknown. The charging circuit wasn’t working. I found the regulator rectifier was only connected to the rectifier circuit. The original points type voltage regulator was still hooked up. I removed the old regulator and connected the solid state unit correctly and it charges good now.

[MLW9110]

Went for a ride. Engine missed badly and wasn’t firing all cylinders for a few miles, then it started running pretty good except idle was unstable. Rode about 40 miles. Strobe checked and adjusted timing. It wasn’t off much.

Put some oil in the gas per HondaMan’s suggestion and will go for another ride after dinner.

[MLW9110]

Rode another 40 miles. Bike ran poorly until it warmed up. Ran well for a while but would start missing intermittently. It does seem like something is sticking and then works ok again. By the time I headed home it was running good. When it’s running good it has plenty of power and is fun to ride.

The idle is getting better too.

I no longer think putting a stock air box on will help.

[MLW9110]

Checked plugs. #1 and #4 looked good. #2 and #3 were sooty. Ckecked points with engine running. The 2-3 points set had a loose contact on the arm that is moved by the points cam. I soldered the contact rivet where it was loose. That seems to have fixed it! Going for a test ride.

Points were new from 4into1.

[MLW9110]

I got a complete airbox assembly on eBay. Pretty rare to find one at a decent price. I got a pretty good deal.

[HondaMan]

I got a complete airbox assembly on eBay. Pretty rare to find one at a decent price. I got a pretty good deal.

Bravo, and GREAT move on your part!

The 2-3 points set had a loose contact on the arm that is moved by the points cam. I soldered the contact rivet where it was loose. That seems to have fixed it! Going for a test ride.

Points were new from 4into1.

Yeah, those scare me. I have some brand new (but real old) 2-3 points in boxes: PM me your address and I'll send you a set without a loose rivet...that solder won't hold long.

[MLW9110]

Thanks for the offer of points. I put a Dyna electronic ignition on. Works good.

[MLW9110]

I've installed the proper airbox I got on eBay. Bike starts and idles better now.

I went for a ride yesterday and the engine lost power. Found the sealer a previous owner used in the gas tank had failed. I'm going to start a new thread on it.