Author Topic: Starting a rusty '77 CB550K (Read 39398 times)

Tvag · « **Reply #25 on:** December 29, 2006, 04:07:42 pm »

Ok, you asked for it. I'll take this on myself. It's going to be a gruling error plagued event but will your help and support I am confident I'll be able to pull this off.

I've chosen a name for her. I dub thee "Dusty Thunder." Pics to come, if I can find a digital camera to borrow.

csendker · « **Reply #26 on:** December 29, 2006, 04:24:50 pm »

Thread steal: I know my carbs need some work too. I'm pretty sure my idle jets need cleaning and my floats are off, I'm running slightly rich and my gas milage stinks. So, if I pull the carbs, tear them down and clean them to within an inch of their lives, then lovingly reassemble with all new bits of rubber I'm only halfway home. But as I have nothing to synch them with, then what?? I'm guessing a bench synch would probably end up with a worse-running bike than I started with.

It's only a partial thread steal as I'm betting Tvag will be in the same boat unless you have a Carbtune hanging in your garage that I don't. Don't get me wrong, I don't want to deter from the do-it-yourself approach, I'm just wondering what to do when they're squeaky clean but out of synch with no tool? I'm guessing the options are:

1. Buy a synchronizer.
2. Find someone with a synchronizer that will loan/help.
3. Find a shop that can and will do it.

BTW, I've got PDF files of the following:

"Honda Motorcycle Carburetion" 29 pgs, 12 meg. Describes the technical aspects.

"Keihin" 5pgs, 1 meg. Tutorial rebuild filled with lots 'o pictures.

I'll e-mail them if you want a copy.

Tvag · « **Reply #27 on:** December 29, 2006, 04:51:21 pm »

Quote

Thread steal: I know my carbs need some work too.

Sure, steal a thread from a poor knowledgeless nubie. Truth is, I don't know what the heck your talking about... but it sounds like something I want to know about!! Steal on brother.

csendker · « **Reply #28 on:** December 29, 2006, 04:56:23 pm »

Most of a carb rebuild is taking it apart, cleaning it and then putting it back together again. But I should be saying "them" not "it" because "it" is actually 4 individual carbs, not just 1. When done they have to be synchronized to operate together in unison so one cylinder doesn't overpower another. There's a set of ports on the manifold that you hook up a set of manometers to (the infamouus synchronizer, of which the Morgan Carbtune seems to be the most recommended) and adjust the carbs so there's an equal vacuum being pulled on each one. I don't have a synchronizer, so I won't pull my carbs because mine are actually working and the bike runs. I pull them and I'm done for in the riding department.

Tvag · « **Reply #29 on:** December 29, 2006, 05:14:04 pm »

SON OF A B!*^%! I have no such instrument as I'm completely clueless. I remember reading in the Clymers there is a brief section on making your own measuring device for the carbs. I believe they call it a manometer or some such thing. Not very descriptive, but interesting if someone has made one themselves I'd be interested to hear success or failure stories. I am a lone biker. I have no friends who bike, will consider biking, or have ever been on a motorcycle. So... I guess I'd better make friends out of some well to do bikers soon so I can use thier equipment.

csendker · « **Reply #30 on:** December 29, 2006, 06:46:56 pm »

Quote

I am a lone biker. I have no friends who bike, will consider biking, or have ever been on a motorcycle.

Ha! Ha! Ha! I'm in exactly the same boat. They go even further by accusing me of a death-wish for simply riding. But I don't care. Seriously, I have the same Clymers. Yes, it's called a manometer and it simply measures the amount of vacuum being pulled through the carb. No rocket science here, and likely the route I'll take when I get the courage to yank 'em off. Its a tube partially full of fluid, one end open to atmosphere and the other connected to the manifold. Vacuum = sucking, so the fluid is pulled in toward the manifold and away from the open end. You just have to set it up so the fluid isn't pulled all the way out the tube and into your engine.

Vacuum is typically measured in "inches of water" or "inches of mercury" where the "inches" is the amount the fluid moves. Water is cheap & easy & safe for you and the environment, but a strong vacuum will move the water column quite a bit, meaning a tall meter. Mercury is much, much denser (but very nasty for both you & the environment) so the same vacuum will move it much less, meaning a shorter meter. Of course, you could use vacuum gauges too. The trick is to hook up four at the same time and tweak the carbs so they all pull the same vacuum, thus the term "synchronize". You focus on matching the vacuums, not hitting a specific value.

There's a bunch of threads discussing different manometers and synching is a constant issue. Just keep in mind when you make your new friends (there's one waiting here in Buffalo...) to find a bunch that don't have fuel injection and do have four individual carbs feeding four cylinders and a thirst for wrenching. Oh wait, you've already found them here.

750goes · « **Reply #31 on:** December 29, 2006, 10:40:14 pm »

If you are reasonably mechanically minded, then synchronising carbs is not that difficult....you just need a good solid work surface and plenty of patience...

after the carbs are disassembled, cleaned, reassembled, then set all slides to the same level.......it will get you well within tolerances of starting the bike, but I would prefer (not knowing the carbs on your bike) to have the selected gauges handy for a final check and adjustment after the bike is warmed up...

rt · « **Reply #32 on:** December 29, 2006, 11:41:40 pm »

Tvag - unless you got a perfect runner anyway, properly adjusting your carbs after checking ignition, valve clearance, etc. is a MUST. I'm riding SOHCs for some years now and was lucky to get away with "tuning by ear" on my bikes till now. A felt lack of performance has never been on my agenda though I must admit I've got nothing to compare with my neck of the woods. As I'm pretty sure a more precise carb setup would give my bikes the edge, I'm using the Winter break to do that now (as my New Year resolution instead of quitting smoking

).
Exact carb synching doesn't necessarily involve high-tech technology and a date with your bank manager. If you're on a budget, the following links might be helpful:
http://www.powerchutes.com/manometer.asp => DIY carb tuner, made from plywood + pvc tubing + pieces of wire = $ 1.55+VAT
http://www.sohc4.us/forums/index.php?topic=10891.0 => homemade tool by OldSchool_IsCool, that sets you back a fiver....

success
ray

TomC · « **Reply #33 on:** December 30, 2006, 06:30:04 am »

Hi Twag
Here is another link with an inexpensive home made carb balancer.
TomC

http://homepage.ntlworld.com/frank.cooper1/frameset.html

csendker · « **Reply #34 on:** December 30, 2006, 06:35:57 am »

What type of vacuum do these things typically pull? # inches water? # inches mercury?

I'm just thinking ahead to any home-made equipment and trying to decide between a dense liquid, making a smaller unit but inherently more difficult to measure change or a lighter liquid making a larger unit but easier to measure change? I supose potential bouncing of the liquid due to uneven vacuum should be considered. And the amount of safety factor (extra hose...) to prevent potential tube-cleaning vacuums too...

TomC · « **Reply #35 on:** December 30, 2006, 06:50:05 am »

What type of vacuum do these things typically pull? # inches water? # inches mercury?

Hi Csendker
I would like to hear a real number from a stock sohc4 in good condition. I have a number in my head of about 20 inches of mercury for a V-8 at idle.
TomC

OldSchool_IsCool · « **Reply #36 on:** December 30, 2006, 07:49:29 am »

I'm not sure what kind of numbers it will pull, but it stands to reason that, at a maximum, it will pull one quarter of your engine displacement per cylinder. For a 550, that would be about 140 cc's. lets say that the tube you are using is quarter-inch and, for ease of calculation, the inside diameter is about a half centimeter. The circle made by the ID then is (3.14)x(0.5)^2 or .75cm. You would need (140/0.75) or 186 cm of tubing. That's like 53 inches or 6 feet of tubing per cylinder.

(Holy Chit! Mr. Wood was right! I will use math in everyday life!!)

Of course, not all the displacement comes up the tube, a lot of it will come through the carb. I'm in the process of building a home monometer. I'll post pics in a minute.

OldSchool_IsCool · « **Reply #37 on:** December 30, 2006, 08:01:08 am »

Here are pics of my attempt at a manometer.

Most of it is aquarium parts. The hardest part to find was the nipples for the vacuum ports (mmmm nipples!). A fellow member pointed me to California Sport Turing, inc (www.CaSportTuring.com). Their sku number is 24003 for the 5mm barbs. Hold on to your wallet... they are a $1 each!

I haven't tried it yet, but another member built one like it. The tubes were short so his engine sucked liquid into the cylinder. He was using ATF (which is actually good for your engine), so no harm done. Some more tweeking and I'm hopeful this rig will eventually work.

kuyarico · « **Reply #38 on:** December 30, 2006, 08:52:49 am »

Quote from: csendker on December 29, 2006, 06:46:56 pm

Quote
I am a lone biker. I have no friends who bike, will consider biking, or have ever been on a motorcycle.

Ha! Ha! Ha! I'm in exactly the same boat. They go even further by accusing me of a death-wish for simply riding. But I don't care. Seriously, I have the same Clymers. Yes, it's called a manometer and it simply measures the amount of vacuum being pulled through the carb. No rocket science here, and likely the route I'll take when I get the courage to yank 'em off. Its a tube partially full of fluid, one end open to atmosphere and the other connected to the manifold. Vacuum = sucking, so the fluid is pulled in toward the manifold and away from the open end. You just have to set it up so the fluid isn't pulled all the way out the tube and into your engine.

Vacuum is typically measured in "inches of water" or "inches of mercury" where the "inches" is the amount the fluid moves. Water is cheap & easy & safe for you and the environment, but a strong vacuum will move the water column quite a bit, meaning a tall meter. Mercury is much, much denser (but very nasty for both you & the environment) so the same vacuum will move it much less, meaning a shorter meter. Of course, you could use vacuum gauges too. The trick is to hook up four at the same time and tweak the carbs so they all pull the same vacuum, thus the term "synchronize". You focus on matching the vacuums, not hitting a specific value.

There's a bunch of threads discussing different manometers and synching is a constant issue. Just keep in mind when you make your new friends (there's one waiting here in Buffalo...) to find a bunch that don't have fuel injection and do have four individual carbs feeding four cylinders and a thirst for wrenching. Oh wait, you've already found them here.

I just want to go on record saying that the mercury variety(Motion Pro) is a pain in the ass and poorly designed. If I had to do it over, I'd shy away from the mercury.

Also OldSchool, I believe that your manometer will be too short. But let us know how it goes.

Klark Kent · « **Reply #39 on:** December 30, 2006, 09:40:55 am »

he called yer manometer short....

until you get everthing else sorted (including cean bench synced carbs ((mmmmm... clean bench synched carbs)) you wont be able to get a proper synch. carb cleaning and a bench synching, plugs and caps that give you good spark, valve adjustment, timing, cam chain tension have to all be set and done. at this point you will have a running bike that makes more noise with the clutch let out thatn it should (just like me) and then you can stalk ebay for a morgan carb tune or go with any of the options here to get them all perfect. but there is a lot of fun to be had with close enough carbs and it should definately not discourage you from the much needed cleaning of the carbs- any more than it would stop you from adjusting the valves.

-KK

edited for meaningful spelling errors

kuyarico · « **Reply #40 on:** December 30, 2006, 12:55:14 pm »

It's not about the size of your manometer, but how you use it

TomC · « **Reply #41 on:** December 30, 2006, 01:41:00 pm »

Quote from: kuyarico on December 30, 2006, 12:55:14 pm

It's not about the size of your manometer, but how you use it

Hi Kuyarice
How you use it is important. But the 20 inches of mercury converts into 22.5 FEET of water! My guess is that a sohc4 will not pull that much vacuum but 10 inches of mercury converts into 11.25 feet and I think a sohc4 should pull more than that. If you use an open u-tube manometer with water or oil you will need a very big manometer.
Frank Copper used a different type of manometer which will work with water or oil with out needing to be as tall as a house.
http://homepage.ntlworld.com/frank.cooper1/frameset.html
TomC

Killer Canary · « **Reply #42 on:** December 30, 2006, 02:23:24 pm »

Dennis Kirk carries a Motion Pro synchronizer for $57 U.S.I paid $95 CDN for mine and it didn't even hurt.If you only use it once, it's paid for with change coming back.At that price, why piss around building one?

Tvag · « **Reply #43 on:** January 03, 2007, 05:17:30 am »

Quote

Take off the eight 10mm nuts that fasten the intake manifold to the studs, loosen all the clamps that hold the boots to the carb throats then go around to the back of the bike so you can get good leverage, lay over the seat, grab the entire rack of carbs with the manifold still attached and pull it towards you. The rubber boots will give enough so you can clear the manifold of the studs then angle the whole thing down towards the ground. Now slide the carbs to the right a bit so you can easily get at the throttle/choke linkage to remove it. Thats it! Pull em out.

Special thanks to Wykydtron and his post on Dec. 29. This really helped me get these suckers out of my bike. Yep, they are definately out and now I'm in it up to my neck. After I removed them I was surprised to see how clean the mouths were and in the bowls. (I will post pictures soon.)

QUICK OBSERVATIONS:
1) There wasn't that much varnish in the bowls but crust had formed on many of the jets.
2) One of the bowls (#2 i think) has a crack and a chip at the base where the screw for the drain is. Looks like it was screwed in too hard and cracked. (This would explain why when I put gas in it that carb kept leaking AND I wanted to start her so bad to solve it I simply plugged that hose with a pencil and continued on my merry way, DUMBASS!)
3) The float on #3 seems loose, and when upside down drops more than the floats on the other carbs (in other words if filled with gas it would fill higher than the other carbs)

Pictures to come as soon as I figure out how to do it. I don't know for sure but at this point if these look as good as I think they do, I might just do as Wykydtron suggests and clean the bowls, idle screws, jets, floats and needle/seats and see if that will do the trick.

Where can I get another float bowl for #2? Am I going to be S.O.L. on this one? Anyone got a float bowl for sale??

And what about the float on #3 being loose? How do I repair that?

Again thanks for all the help guys. I would have never gotten this far without this forum. The books are of little help when you are as limited in knowledge as I.

kuyarico · « **Reply #44 on:** January 03, 2007, 07:39:52 am »

You should be able to adjust the float height by bending the section that makes contact with the float pin, however you should measure and adjust all of your float heights. This procedure can be found in the Carb FAQs or here: http://www.salocal.com/sohc/tech/carb/carb.htm. There are very specific specs on float heights. I don't have my Clymer handy, but I'm sure someone will chime in here with the proper spec.

Also, www.ohiocycle.com may have the float bowl that you are looking for.

Tvag · « **Reply #45 on:** January 04, 2007, 10:18:25 am »

Some pictures for OPERATION: Dusty Thunder

The full rack off my CB550K.

Carbs 1, 2, and 3 w/ float bowls off.

Carbs 2, 3 and 4 with float bowls off. Not aweful for 20 years I would say. BUT...

HERE'S the crack in #2 float bowl. This carb was spewing gas out of the drain tube when I was trying to get her started. This would explain why. There are 2 pieces that chipped off. I got some DP Weld and hope to fix it for now... It's going to be a tough tough surgery.

Here she is in all her Glory. Lots of scrubbing to do...

I'll be taking lots of pictures throughout this project so I can put her back together. I'll try to keep them posted.

medic09 · « **Reply #46 on:** January 04, 2007, 12:48:00 pm »

It'll be glorious when you're done!

Tvag · « **Reply #47 on:** January 04, 2007, 01:30:35 pm »

I'll try and get some tank pics tonight. From a cursory inspection the tank appears to be in very good shape. A couple tiny spots of rust right under the gas cap from my first inspection. I think most of everything on the insides are pretty good. Externals need all the work. Tires, wheels, brakes, air filter, clutch on and on... these things all need a lot of attention. so.... I'll clean the carbs then fix the brakes. If she starts GREAT! I'll break her down, clean, paint and replace everything that needs it. Over time of course. I'm a poor poor POOR grad student. I'm looking at this puppy as a backup means of transportation... as soon as I can get her up to par.

Quote

Damn dude! Did you pull that out of a lake?

And, NO! I didn't pull it out of a lake! It was in a shed for 20 years untouched. Want to fight about it!!

j/k

750goes · « **Reply #48 on:** January 04, 2007, 01:53:30 pm »

Just for your benefit - put an inlline fuel filter in after you have flushed the fuel tank...just another little safety measure after all the hard work cleaning those cqrbs...good luck....at least it looks complete

jensk · « **Reply #49 on:** January 04, 2007, 02:19:53 pm »

Wow T.
This one looks even worse than mine allthough your CB550 doesn't seem to have been involved i an accident as mine has. My project is also restoring an CB550K. Mine is from '77.
I am allmost through my carb cleaning and restoring. Presently I am waiting for new jets to arrive since i changed it from pod airfilters back to original airfilter setup with the original airfilterbox etc. I have ordered them at the local Honda dealer. They think they can get some original jets from the danish Honda distributor. I hope they arrive soon so I can assemble the rest of the carbs and mount them.
In the meantime i am working on repainting my gauges. The original gauges were broken from the PO's accident. I got some cheap once from a broken german bike. They were cheap because they were painted red. I have disasembled then and painted them black again.
/J

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Author Topic: Starting a rusty '77 CB550K (Read 39398 times)

rt