Author Topic: Starting a rusty '77 CB550K (Read 41079 times)

nomadwarmachine · « **Reply #100 on:** January 19, 2007, 01:39:59 PM »

+1 TwoTired. Start with a compression check -- everything else can be brought into line relatively inexpensively, but a blown gasket, worn rings or scored cylinders may put this project in an entirely different perspective.

I've brought several old Hondas back to life and I've learned that you always try to set a baseline of known quantities (compression, valve s, timing) before trying to track down more specific trouble. Bad running is not a problem, but a symptom of a problem that can have multiple causes. Once you set your baseline, you can begin to narrow down the possibilities (bad coil/wire/plug/idle circuit/filter/fuel delivery) until the symptom goes away. In the long run, you will be more familiar with your machine and more confident that you can fix it should problems arise in the future!

WJL75 · « **Reply #101 on:** January 19, 2007, 02:07:26 PM »

I am almost a little envious of you taking a bike from nothing and getting it to run. It is a complete motivator for me to keep workiing on my project. I fullly understand how many here become hooked on these bikes. I am taking a running 76 550K that needs some love and working on it this winter. I get a grin from ear to ear when a fix the smallest of things on it. I can only imagin the joy you felt the first time you got the carbs back on and the bike running. Keep up the good work and keep the updates coming!

Tvag · « **Reply #102 on:** January 22, 2007, 05:00:39 AM »

Well, I'm going to take a break from the engine and carbs. I got it to start and run which was my original goal. So that project is done... just for now. I've turned my attention to the brakes.

I removed the front brakes this weekend. They have siezed up and have been locked on since I've gotten possesion of the bike. I pulled on them once and that was it. Front brake locked up. So... this weekend I tried to free them up. I got some brake fluid and flushed the old brown grainy brake fluid out. The brakes obviously still wouldn't work because the piston is stuck. So I took the front brakes off. I was able to get the pads out but I can't get the piston out. It's stuck. I tried to push it out while it was still attached to the brake system but it wouldn't pop out. I don't have an air compressor or else I wouldn've used that. Any suggestions?? Thanks all.

csendker · « **Reply #103 on:** January 22, 2007, 08:20:53 AM »

use a hand-held grease gun. unscrew the fitting at the end of the gun and it should gently screw into the brake line connection for only a couple of threads at best. They're different thread pitches, so be careful, you just want it to hold on with a minimal seat. Then pump the grease into the caliper and it will force the piston out.

TwoTired · « **Reply #104 on:** January 22, 2007, 10:39:05 AM »

What I do is clean or rebuild (as required) the master cylinder first. Then use it to pump out the caliper piston while it's dangling from the hose. The lines get flushed in the process, too. I usually bleed the system from the master end anyway. Bubbles rise.

I wrote a caliper rebuild walkthough some years ago that used to be on the SOHC4.net site. But, I can't find it anymore. I guess Glenn threw it away.

Oh well.

Tvag · « **Reply #105 on:** January 22, 2007, 11:47:00 AM »

I did successfully bleed the old fluid out of the system and replaced it with fresh DOT 3. I cleaned the crustly sludge from the master cylinder, put in new DOT 3, attached a hose to the bleeder and got all the nasty fluid and air bubbles out. When I closed the bleeder and filled the master cylinder back up I didn't see any improvement in the functioning of the brake. I then tried to pump the brake to get the piston out but it wouldn't pop out nor would it retract. It stayed just where it was, jammed. It doesn't feel like there is any real force behind the hand brake. Am I not getting enough pressure? Maybe I didn't bleed the brakes correctly?

750goes · « **Reply #106 on:** January 22, 2007, 12:19:22 PM »

Is the brake lever spongy or hard - does it "pump up" or become harder after a few uses of the brake lever - that should tell you if there is something not right

A squelchy noise up in the master cylinder area could mean you need to rebuild that as well.....is there fluid coming from around the lever pivot area as welll?? - you may have to gently lift the rubber cover to see this..

hcritz · « **Reply #107 on:** January 22, 2007, 12:35:01 PM »

Tvag...
You may be able use a C-clamp and slowly push the piston back into the caliper...this will at least break it loose...then pump the piston out with the mastercylinder...
Loosen the cap on the mastercylinder when you do this. This may also help bleed any air still in the system by pushing it out the top.
Does sound like you still have air in the system.
Also make sure that the brake lever springs back all the way...if the piston in the MC sticks it may not be allowing fluid back into the system. I've seen a lot of them that have corrosion built up at the end of the MC and not return properly.

TwoTired · « **Reply #108 on:** January 22, 2007, 02:02:46 PM »

Quote

It doesn't feel like there is any real force behind the hand brake. Am I not getting enough pressure? Maybe I didn't bleed the brakes correctly?

No, it doesn't sound like it. There are two holes in h bottom of the master, one of them very tiny. This is where air bubbles come out when they rise to the top of the liquid reservior (the braking system). Check that the tiny hole is clear. Then, with MC filled, move the lever slowly and you should see bubbles rise with each stroke of the lever. When enough bubbles escape (air being replaced with fluid) you will begin to feel resistance at the lever. High internal pressures make very tiny bubbles that take forever (okay overnight) to rise to that bleed hole. So keep the pressures low until you get a firm hard lever. Then simply pump the caliper piston out into a bucket or pan. It is possible to bleed the entire brake system on single caliper brakes in this way. Just position the bike so that the MC bleed hole is the highest part of the system.

Cheers,

Tvag · « **Reply #109 on:** January 23, 2007, 05:30:03 AM »

Well, I'm going to take apart the master cylinder and thouroghly clean it this week. I got the caliper off the handle bars and cleaned all the exterior. Any suggestions on how to get that hard to remove crud off the walls of the Master? Sandpaper? Anyhow, I've been reading a lot about this evil 'snap ring'. Last night I couldn't see it. In my manual it appears to go on after the rubberboot. But I see no evidance of it when I look down into the caliper to find it. I had a pretty good light too. From what I can tell it's all the rubber boot down there. Wait, I just figured it out. It's assembled AFTER the boot but goes UNDER the boot doesn't it? Probably down at the base of the piston huh? Well, glad the forum is hear so I can work the problem out by putting it to words. Thanks for listening...

So if I have mentally mapped this correctly, I just need to get some special pliers between the boot and the piston and pinch the two ends of the clip together, in effect shortening it's circumference enough to slide it out from around the piston and under the boot? A 'bingo' might be in order here. Can I get a 'BINGO'?

nomadwarmachine · « **Reply #110 on:** January 23, 2007, 09:40:18 AM »

Bingo!

Get the longest-nosed set of snap ring pliers you can find. Getting that thing out can be a paing, but you are on the right track.

BobbyR · « **Reply #111 on:** January 23, 2007, 09:49:12 AM »

Denatured Alchohol will dissolve the crud.

jensk · « **Reply #112 on:** January 23, 2007, 02:23:36 PM »

Hi Tvag.
I have given your plug picture a couple of thoughts. The plug picture you get might come from swapping ignition caps between cyl #3 and cyl #4 sparkplugs. If they are swappet you will have spark on cyl #3 when #4 is in its compression stroke and should have the spark and vice versa. Are you sure that you have got them right when you put the spark caps back on the spark plugs?

Tvag · « **Reply #113 on:** January 24, 2007, 04:58:09 AM »

Jensk, I'll double check when I get back home. I've been pretty careful though. Friends who are more knowledgable than I think it might just be a sych problem. I'm keeping my fingers crossed.

I removed the circlip last night from the master cylinder. It was great fun. I probably spent 40 minutes overall fiddling with a pair of small pliers. Upon removal I noticed the boot on the piston had a small tear in it. This would explain the mess I found outside of the caliper. Apparently it had been seeping ever so slowly. I was hoping I didn't need to get one but it looks like I'll need a rebuild kit, unless anyone here has an extra boot they'd like to send me. The rest of the parts are in good shape (even the circlip), nasty maybe but in good shape. Suggestions on kits??? I'll do a search on the forum but welcome suggestions or boot donations!!

dagersh · « **Reply #114 on:** January 24, 2007, 11:13:09 AM »

Tvag,

If the ter is samll enough, try mending with "Shoe Goo" - sort of a flexible, very strong glue meant for fixing sneakers.

Soak all those nasty parts in Denatured Alcohol (NOT SCOTCH!!!!!). You should also think about flushing the rest of the system with the alcohol as well. This would allow you to switch to DOT 5 (IMHO - not trying to start a war....) and have a nice water resistant brake system.

Keep up the great work.

BTW - which pliers sis you end using to get the circlip out?

Gersh

Tvag · « **Reply #115 on:** January 24, 2007, 11:34:19 AM »

Gersh,

Denatured alcohol? Do you mean rubbing alcohol??

The tear is a pretty good size, and the ring at the bottom of the boot is exposed... I really just need a new one... but I'll keep Shoe Goo in mind for the future. Good tip. I've got nothing against mending parts that I can.

Stupid boot. $31 plus shipping for a rebuild kit? I'm having a hard time rationalizing that purchase for one little rubber part. Grrrr.

Tvag

TwoTired · « **Reply #116 on:** January 24, 2007, 12:28:27 PM »

Quote from: Tvag on January 24, 2007, 11:34:19 AM

Stupid boot. $31 plus shipping for a rebuild kit? I'm having a hard time rationalizing that purchase for one little rubber part. Grrrr.

Is it worth $31 plus shipping to stop your bike quickly and safely? What's your deductible on Hospitalization?

Mankind is NOT a rational animal. Mankind is a rationalizing animal. Or, so I've heard.

Cheers,

P.S. If you found brake fluid goo behind that outer rubber boot, that means the seals farther in the MC aren't doing their job. The outer boot is to keep dust out, not fluid in. I'm thinkin' you might just need the whole MC rebuild kit. But, I'm not see'n things first hand.

Tvag · « **Reply #117 on:** January 24, 2007, 12:51:23 PM »

Quote

P.S. If you found brake fluid goo behind that outer rubber boot, that means the seals farther in the MC aren't doing their job. The outer boot is to keep dust out, not fluid in. I'm thinkin' you might just need the whole MC rebuild kit. But, I'm not see'n things first hand.

This does make me feel better about the purchase. I have to keep it in mind that I'm investing in an education, not a bike.

dagersh · « **Reply #118 on:** January 24, 2007, 12:56:22 PM »

Quote from: dagersh on January 24, 2007, 11:13:09 AM

BTW - which pliers sis you end using to get the circlip out?

Uhhhhh, that should have read "did"!!!!

medic09 · « **Reply #119 on:** January 24, 2007, 01:14:18 PM »

http://www.newton.dep.anl.gov/askasci/chem00/chem00102.htm

I would stick to actual denatured alcohol, to ensure that you're not introducing water molecules into your system.

Tvag · « **Reply #120 on:** January 24, 2007, 01:17:10 PM »

Quote from: dagersh on January 24, 2007, 12:56:22 PM

Quote from: dagersh on January 24, 2007, 11:13:09 AM
BTW - which pliers sis you end using to get the circlip out?

Uhhhhh, that should have read "did"!!!!

Sorry!! And old set of small needle nose pliers from my grandfather... ancient devices and they were made of soft metal so I had to keep prying the nose back into shape after every attempt at the circlip.They were small enough to fit into the little eyes. I'll take a pic and post if you want... Good thing I had them... or my investment in the master cylinder rebuild would be more like $50

Tvag · « **Reply #121 on:** January 25, 2007, 05:00:33 AM »

Quote

Sorry!! And old set of small needle nose pliers from my grandfather... ancient devices and they were made of soft metal so I had to keep prying the nose back into shape after every attempt at the circlip.

Spoke too soon. Last night after cleaning the master cylinder I was experimenting with the reinstallation and that blasted circlip broke the nose off my pliers!!

I'm thankful though that at least they broke after the circlip was out. Guess I'm in the market for some new snap ring pliers afterall.

OldSchool_IsCool · « **Reply #122 on:** January 25, 2007, 08:58:55 AM »

Tvag,

I came across these the other day. I've never used them, but I bet they are just what you need. Sad that you may only use them 2 or three times hen not again for years!

http://www.motionpro.com/motorcycle/tools/master_cylinder_snap-ring_pliers/

If you do order them, you may as well get a tappet feeler gauges too and save a little on shipping

http://www.motionpro.com/motorcycle/tools/tappet_feeler_gauges/

You will want the .002 - .003 in gauges for your 550.

Tvag · « **Reply #123 on:** January 25, 2007, 09:15:50 AM »

Thanks OldSchool,

Those look like they'll do the trick. But your right!! 2 or 3 uses MAX!

Oldschool, did you rebuild your Master Cylinder? I can't find a kit for the '77 cb550's. It's almost like they have every other year but '77. If so, do you remember where you got it? (OEM# 45530-404-305).

OldSchool_IsCool · « **Reply #124 on:** January 25, 2007, 09:26:33 AM »

hehehe, actually, I was waiting for you to find a source! <GRIN> Front brake work is my next project after I regasket the top of my motor.

I'd give Western Hills Honda a try. (513-662-7759) and ask for "Vintage Parts".

Tip 'o the hat to Jonsey for giving me the leads on Western Hills and on the tappet gauges. Can't imagine trying to adjust tappets without 'em!

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Author Topic: Starting a rusty '77 CB550K (Read 41079 times)