74 Honda CB550 Four - Newbie enters the arena...

[mcenz25]

The subject line says it all, I've gotten my hands on a 74 CB550, and I am as new at this as I can be. The only thing I bring to this project is passion and a plan. The passion is self explanatory given the company kept on this forum, but the plan is where I will likely need some guidance. Here is what I know; start small, complete a single task before moving on to another, and be humble enough to ask for help where needed.

I’m attempting to document as much of the tear-down and build as possible. I have a few pictures of the bike as delivered. They’re not great images as I’m a newbie to photography as well.

I knew up front that there was the possibility of low compression across all four cylinders. To date I haven’t run a compression test. I really wanted to see if I could just get the machine to breath again before running any tests. New gas, cleaned petcock screen, drained carbs and I was off to the rodeo. It runs! Well, sort of, it was (as reported) low on power. I used a IR temperature gauge to see how much difference there was between cylinders. One & four were much cooler than two & three. Points? Checked ‘em. Condensers? They both fell into range. Turns out a solenoid ground pulled out of the harness. I hooked that up and excitedly hit the starter. Did I mention that the bike would idle (sort of) before finding the solenoid ground unplugged and while firing on only two cylinders? Now with all four firing I can’t keep the engine running more than thirty-seconds or so.

This is all part of the learning curve for me and while I’m certain that some of the veteran’s in the community are getting a chuckle over my fumbling, I couldn’t be happier!

I hope to share the project with the community, ask questions now and again, and maybe learn a little along the way.


Maybe one question or two...

Most of the chokes I have experience with have been operated by pulling a knob to close the butterfly. This bike has a lever with the word Open and a curved arrow pointing down. Here’s my assumption, pull the lever up to horizontal to start and then push down to vertical for normal operation? Have I got that correct? Any idea why the bike would run better on a closed choke than an open one?

Greg

 

[Tim]

Greg - welcome to the site, and let's see some pics!

The choke lever operates the bank of 4 butterfly plates simultaneously. If it runs better on a closed choke I'd think it was running lean when the choke is open.

If you use the Search function, you'll find a nice PDF scan of the original Honda Service manual for the bike. My first ride was a 1973 CB500K and then I had a 1976 CB550F. I've rebuilt the engine a couple of times so I remember most of it.

 

[DoubleClutch]

Yes Tim is correct!! If it runs better when the chock is on then you need to do a carb cleaning on all the carbs. Pull the jets and make sure all passage's are clean and not plugged. It would be best to get new rebuild kits instead of trying to get buy with old gaskets, jets and such. Also synce the carbs when you go and put them back on.

 

[mcenz25]

Here it is...not clean and some miscellaneous parts removed.

 

[mcenz25]

Two images...just for fun.

 

[mcenz25]

Thanks for the explanation on the choke. I'll get the carbs off, clean and rebuild. One step at a time!

 

[DSmoke]

You have a great attitude! I am no master mechanic myself, but I am getting by and learning as I go. I think most here learned the same way as your about to. Just give it a try, might not get it the first time, but the second time is always easier than the first. I am slowly becoming the carb guy among everyone I know. Why? Because I'm not afraid to take them apart to figure out how they work, and I'm not afraid to reject them. It's all fun for me. Worse case, I read something or post a question to a forum to get some help.

Good luck! And great looking bike!

 

[VTNick7]

Great looking bike! Looks just like mine.. I'm in the same boat as you. Learning as I go along, but it's been a lot of fun. Good luck!

 

[carnivorous chicken]

Here’s my assumption, pull the lever up to horizontal to start and then push down to vertical for normal operation? Have I got that correct? Any idea why the bike would run better on a closed choke than an open one?

Just because nobody's answered this directly, yes, that's right.

And aside from seeing if it's running lean, check your float height.

 

[mcenz25]

I managed to get the air box and carbs out this afternoon. I didn't have an abundance of time to go further than that but the goal was rather simple anyway, get the carbs out...maybe do some poking around. I was able to remove one bowl, float, and needle to see what condition everything was in. I was afraid that there would be some residual gumming up of the old fuel, even though I removed the drain plugs and let fresh gasoline pass through until it looked clean. I'll tackle the other three tomorrow. Any advise on types of cleaners, procedures, or general guidelines to follow.

Greg

 

[DSmoke]

There are two options, ultrasonic cleaner, or chem dip. I spent the money on the ultrasonic cleaner and use it all the time. I have used many different things from soap to cleaners, all seem to give pretty good results. The chem dip is nice, but takes time. You should also have a compressor to blow out the passages.

Take one apart at a time. Do a google search or search here for a post with pictures of someone cleaning a carb. Or, get yourself a service manual. This will give you a good idea. Take everything apart, and I mean everything. If you don't you will probably be cleaning them again. If the rubber parts are old and hard buy new ones.

 

[edukaycheon]

To get your standard grime out you can usually take a cloth and solvent to it, but yeah for harder stuff you'll need to have a clean baseline to start out with, which means the ultrasonic or chem dip. Also x2 on taking everything apart, you will have to pull them off again to do jetting and tuning but making sure they're clean and functional will save you some headaches down the road