Topic: 77 cb550k

[Kurosh215]

I can probably find my answers if I dig a little deeper, but throw me a bone here. New guy on the block.

Picked up my first bike back in March. I replaced a few things like the oil filter and bolt, brake lines and master cylinder, gas tank, plugs, and within the week I'll put on a new horn and headlight. Ordering a new caliper and pads, not sure what else should be changed, safety wise.
After I changed the plugs, sprayed some carb cleaner in the tops of each one, and finally got the new tank, she fired up nicely after sitting for 30yrs (last registration sticker exp '87). I'm no expert but I could tell only 2 cylinders were firing. I reluctantly took off the carbs and tried my hand at cleaning them. I had some improvements but ultimately had to call in reinforcements.
I finally have her back and got to ride for the first time since buying it almost 7 months ago. Not quite like a dirtbike but damn it feels great!

To my point....
Ever since the first time I got her fired up, I noticed the left side of the base gasket leaks, as well as whatever is under the side cap near the trans (with wires running out the back). There's no way in hell I'm going to tear open the motor just yet. I'd like to know if anyone has used stop leak, I'm looking for facts, so please spare me your biased opinions. I was hoping an ounce or 2 might help thicken things up just enough but I don't want to hurt the clutch or clog any pathways. My other thought was putting a little gasket maker or something similar around the outside of the motor.
The neutral light also seems unresponsive when the bike gets hot, not necessarily overheating. Once the light starts acting up I have to shut the bike off to put it back in neutral. This also disables the electric start.
Last but not least (for now), I have to keep playing with the idle screw as the bike warms up. Not sure if I just need finer tuning on the carbs or what. I can get it to idle nicely around 2000rpm, if I try to bring it closer to 1000 it wants to shut off. Not sure the factory idle speed.

Any input would be helpful and much appreciated. Thanks.

[Bankerdanny]

The '77 has a fast idle cam built into the choke setup, you set the idle when fully warmed up and then should not need to mess with it again.

You also should only need the choke for a few minutes accept during the coldest weather.  In summer I could often start my 77 without any choke.

After sitting a long time the clutch could be sticking. It could also just need adjusting. Difficulty getting neutral is a common symptom of an out of adjustment clutch.

DO NOT USE STOP LEAK UNDER ANY CIRCUMSTANCES.

A minor oil leak is nothing to worry about. The oil passages are tiny and you do not want to clog them.

The neutral light should not be affected by engine temp. It's  a simple mechanical connection that can get out of adjustment.  The switch is located under the sprocket cover just above and in front of the front drive sprocket.

[Bankerdanny]

Make sure your oil is motorcycle oil not car oil and that it is rated for wet clutches (clutches that run in n an oil bath). Auto oil has extra additives that can have a negative impact on how well it works.

[BomberMann650]

Taking off that left case cover is harmless to the motor.  There are a few things under there which frequently leak.  O-rings and rubber seals that shrink up.  Common and simple items to replace. 
Most of which are the oil pump seals.

[Kurosh215]

Thanks a ton for the input! I wasn't sure if oil would drain out if I popped the cover off since it looks like it's leaking there too but I guess that wouldn't matter anyway since I need to flush out the car oil I used.

[Scott S]

 The chrome cover in your pic is the starter cover. There's no oil in there. There IS a seal where the starter slips into the engine. It's unusual to see oil coming from that cover. Have you taken it off to see what it looks like in there?

 If there's oil coming from the sprocket cover, it's most likely the shift shaft seal. Cheap and pretty easy to replace.

 The base gasket.... You may get by with retorquing the head, but that means removing the rocker cover and replacing the rubber pucks when you're done. Truthfully, the real fix for that is new head gasket, base gasket and pucks. There's no "quick fix" for that.

 Please, DO NOT use stop leak and DO NOT smear silicone all over the engine. Do it right or not at all.

[uksparky]

Idle speed hot is around 12,000 rpm if it stalls out more than likely you have blocked jets in the carbs....pilot and main jet.....been through this myself, also the oil leaks head  and base gasket them O rings get hard....when the oil starts dripping on your boots when riding then its time to 

[Deltarider]

If a CB500/550 sits for a long period of time, it's not unusual it will show the leakages you describe when it's started again. If I ride my bike regularly, oil leakage is much and much less. Not to start an oil thread, but the oil I run (Castrol GTX 15W-40 High Mileage) is better against leaking than other oils. I guess I'm one of the very few that still has the original shifter O-ring in place. I remember when I ran the full synthetic Mobil 1, I had to renew the oilpump O-rings within the first 1000 kilometers. 

[Bandit18]

My shifter seal was leaking on my 78 550k. Very easy to change..hit up youtube.

[jamesk]

  The base gasket.... You may get by with retorquing the head, but that means removing the rocker cover and replacing the rubber pucks when you're done. Truthfully, the real fix for that is new head gasket, base gasket and pucks. There's no "quick fix" for that.

 Please, DO NOT use stop leak and DO NOT smear silicone all over the engine. Do it right or not at all.

^^this x1,000.  Take that advice. 

[BomberMann650]

If the oil pump seals went bad, there could be a good bit of oil inside that cover's cavity. 

[Kurosh215]

I'm assuming the sprocket cover is the rectangle one over the trans? I haven't opened either cover yet, sounds like I'll be doing that and getting some better oil in there this weekend. Thanks again for all the feedback

[BomberMann650]

Negative.  "Sprocket cover" IS the big left crankcase cover.  Chrome cap is the starter cover. 

Remove in this order.
1) starter cover.
2) shift lever.
3) crankcase cover

[Kurosh215]

Will be sure to pop those open whenever this rain passes. I tackled the headlight and horn today, got them both working now. While I was in the headlight housing, aside from being a cluster #$%*, I noticed I have a green and brown wire leading nowhere. Someone was in there before and replaced a couple wires so maybe they've been bypassed. Doesn't seem like an issue so far. I had to change some fuses, I guess there's 2 main fuses? There was a 7A main blown and to the right of it was a 15A on its way out that appeared to be a main too? Everything except the headlight worked before replacing the fuses though.

[Deltarider]

I noticed I have a green and brown wire leading nowhere.

This is normal. See the wiring scheme. Has to do with an extra Ba9s bulb that is fitted in the reflector in models destined for other markets

[TwoTired]

...I noticed I have a green and brown wire leading nowhere...

Some markets had a front parking bulb.
Brown is run light power, Green is Batt negative return.
The diagram in the shop manual shows this.

I had to change some fuses, I guess there's 2 main fuses? There was a 7A main blown and to the right of it was a 15A on its way out that appeared to be a main too? Everything except the headlight worked before replacing the fuses though.

The stock bike had one main fuse (15A), and also a 7A headlight fuse, and 7A tail fuse.  The stock fuse block also had spare fuse clip positions for both a 7A and 15A storage.

If your bike has stock wiring, color code definitions/asignments are in the FAQ/electrics, reply #9.

Cheers,

[Kurosh215]

Thanks again, I'm terrible at reading wire diagrams but good to know I'm not missing anything

[Bankerdanny]

The position of the stickers for the fuses make it hard to see which position is which fuse.