Topic: 1977 CB550F IDK (first build)

[minimo]

That was a sketchy tow. Make sure to specify motorcycle next time. Glad you made it home safely along with the bike.

Thanks, CB750. I did specify to AAA that it was motorcycle. The rep even asked, "Does the bike have fairings?"
The towing experience was more frightening than the flat! Sheesh.

[minimo]

I just noticed this!
Great chart. Good idea! Thanks for sharing, JMS28411.

My son and I purchased a 1977 CB550F March 2014, we still have a few mods to make, we currently have a stock exhaust with a severely chopped stock muffler and UNI foam filters attached is a spread sheet of our various carb settings which you may find helpful

[SOHC4 Cafe Racer Fan]

That was a sketchy tow. Make sure to specify motorcycle next time. Glad you made it home safely along with the bike.

Thanks, CB750. I did specify to AAA that it was motorcycle. The rep even asked, "Does the bike have fairings?"
The towing experience was more frightening than the flat! Sheesh.

That just plain sucks. I've had to use AAA roadside over the years more times than I'd like.  Sometimes it takes a while but they always arrive with a flatbed.  Somebody between dispatch and the tower screwed up your request.  I bet you were sweating bullets with your bike perched on that towing arm.  At least you got off relatively cheap with the tube only replacement, if that's a silver lining.

[minimo]

So I'm kind of embarrassed to reveal this but I think I imploded my header - at least the gasket, maybe...

I think I choked my engine by stuffing the end of a vinyl tube I ran from the breather to the rear of the bike (under the rear fender) and may have packed the end of it too full and hard with 0000 steel wool. What was I thinking?

[goldarrow]

Hmmm....crap!




Oh well,....degrease it, hose it down, and ride on and see what happen??? Clear the breather hose as that steel wool wasn't part of the deal


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[strynboen]

it need to breath easy in/or aut that bottel... do not kompress the filling..it is just there to hold the oil damp a bitdovn in the bottel..do not fill it in the line...them you Blocks it total.,..it need to breat total freee..or you build pressure up in the engine
just fill a bit loosenly dovn..and use some nylon svamp(..mine idea of steelvoll.vas not good.).nulon dont harm..but i think not it can be suckt in the engine..specily not your steam engine..it blow only


but try to run it..vitaut any steelwoll..then all kompresion are blown aut.....just go for a ride...but thek for oil level..

[calj737]

I would remove the tappet covers, check the valve adjustments, pop the exhaust off, and verify that your steel wool isn't sucked into the head. That motor no longer sounds "good". And double check your cam chain adjustment while you're at it.

[minimo]

Ugh.

Steel wool has been pulled out; it didn't get sucked into the head as I had it packed in the vinyl tubing tight enough to stay at the butt end of the tube. I guess I basically suffocated the engine :-(

I will clean it all up first as there's oil pretty much everywhere. Then I'll check the valve adjustments and make sure the cam chain is fully tensioned and then go from there.

I'm hoping that the cylinder head cover and cylinder head gaskets aren't completely toast as oil appeared to be dribbling out between those parts. We shall see...

Thank y'all!

[minimo]

Removed the tappets and definitely looks like it was drowned in oil - remnants of oil around the valves...


I imagine that the breather was plugged to an extent that like a steam pot, the oil bubbled and boiled to the top, drowning the valves. Yikes.
I'll readjust the valves but should I go in and wipe them down or will the oil just burn off?
Fack!

[seanbarney41]

Dude, that oil is supposed to be there...it's what keeps your  valve train alive.

[minimo]

Ah, so it is!
I'm always in awe with how these engines are built. I forgot that I even rebuilt this thing and admittedly don't know how it all works. How could that even be? I'm such an imbecile. I'll try not to ride like one.

[minimo]

So, this can't be good...

What you're seeing in the bad pic above is a considerable amount of oil collected in my makeshift breather tube runoff, which I have ziptied snugly (not tight to constrict) to the rear, ending behind where the license plate hangs down beyond the rear fender. Yes, it's just the tube with nothing to obstruct the flow like steel wool. Oh dear.


After readjusting the valves I went out for another ride and there was still a slight leak but not dribbling down like b4 - more like drops. There is oil buildup on the left side - seems to be coming from the gasket between header and cylinder on very left. Ugh.


I need to make this right. Help.

[SOHC4 Cafe Racer Fan]

Bad location for the run off, too -- right onto your rear tire!! 

[calj737]

Clean the motor, and use baby powder or talcum powder applied to the seams of the head and jugs. Then run the motor. Locate the wet spot. Once you know "where its leaking", understanding and troubleshooting the cause will be much easier.

The oil running in the breather tube is very troubling to me (not to mention Don's point about draining over your tire!!!!). Please confirm the oil level in your bike via the dipstick. Then smell the oil on your fingers. Does it smell at all like gas?

[minimo]

Thanks, guys.
Noted on the bad location of the breather tube. Will reroute.
Nice trick with the baby powder. I will clean the engine and give that a shot.
Thanks!!!

[minimo]

It appears I went a bit overboard on the motor oil so I drained it a bit. Before that, I took a whiff of the oil (especially the oil that leaked into my breather tube) and there was a faint trace of gas... Not sure 'cos I'm just getting over a cold so my olfactory senses are a bit impaired. In any case, the foggy breather is indicative of fuel leaking into the engine somehow, right? I'm going to lean toward removing my carbs and rechecking the float heights and for any debris that might be clogging the passages. Before anything though, I need to suss out this oil leak.
I cleaned up the engine as best as I could, kicked the engine over and ran it in idle for a couple of minutes to dry it off and then brushed a coat of some baby powder around the seams of the mating layers of the engine. I'll let this sit at least overnight or the next couple of days and periodically check to see if I can source the leak (great trick, calj737). I know that the leak has only occurred when I put a load on the engine so that'll have to be in the next couple of days before I go out for a ride. Keep y'all posted. Thanks!

Oh, and I also readjusted the valves, made sure there was tension on the cam chain, and rerouted my breather hose to align with my exhaust bracket that attaches to the right rear foot peg. There are no kinks in the hose and there are slight dips/valleys for any oil to puddle and not drip out (not drip directly onto the rear tire, sheesh). I think this is a better location...

[martin99]

If you're dripping that much oil out the breather you might want to consider using a catch-bottle that you can tip out periodically. Keeps the oil away from your tyre and safer for everyone else too. We used to use an empty beer can back in the day, zip-tied to the frame. Whatever you use, just make sure the end of your tube cannot become immersed in the collected oil.

[minimo]

Point well made and good idea. I think strynboen also touched on the idea of a catch can. I'll definitely look into craftin' something for this.


I also wanted to point out the position of my overfill fuel tube and and where it drops right down over carb pod #1... I should probably try to extend this out elsewhere, right?

[martin99]

The manual should show you the correct  routing for that. On the '77 750F it runs along the right frame rail, under the seat and exits toward the rear. Don't know about yours though. As long as you avoid the possibility of fuel dripping on to hot engine cases it doesn't really matter where it goes.

[JMS28411 I'm no Spring Chicken]

Oil on your tire means lost traction, if your engine oil is at the correct level there should not be much oil coming out of the breather tube, just oil vapor. I routed my breather tube so that it sits a couple inches above the chain to give the chain a light coat of oil, works good

[firebane]

In your pic of the tube with the liquid sitting in that... how much is oil and how much is water? Don't forget that in low spots like that vapor will collect easily.

Keep the tube tight and with a slight downward angle towards the back and AWAY from the tire.

[minimo]

Thanks, firebane and y'all.

That baby powder trick worked great on finding where exactly the leaks were coming from! Not only did it manage to sop up a lot of the residual oil that was around the engine after wiping, I was able to pin-point the source of what turned out to luckily be a tightening down of some nuts/bolts mainly around the top head cylinder, especially the top bolt holding the chain tensioner - was somehow able to get a full turn out of that bolt, hmmm. Also replaced the crush washers under the cylinder head side cover settings. I'll see if any replacement is necessary on those o-rings. But with a light ride around the neighborhood, I'm pleased to say there are currently no leaks. I will have to travel a greater distance to see if the tightening up is really all that was necessary but seems to be looking and running good now.

I also ran the vinyl breather tube down along the bracket that holds up my muffler - away from my rear tire. I think this should suffice for now and it's hidden from view pretty well. But I picked up another trick from some of the racers at Willow Springs. Seemed like an inside theme among them to catch the breather hose vapor into an empty bear honey bottle that was mounted upright and ziptied to the frame. Seemed kinda cheeseball and cute but functional all at the same time.

[calj737]

Are you saying that many of the cylinder head nuts were loose? If so, I hope you re-torqued them properly and in sequence, and did all of them, not just the few that were loose. Or are you referring to the valve cover screws/nuts? If so, use care here too as the maximum amount of torque for them is 8#.

If it was the valve cover, then I'd attribute it to using a non-OEM seal as the aftermarkets are often smaller in diameter just enough to require some extra "umph" to squeeze the cover shut.

[minimo]

Yes, these were from an aftermarket non-OEM NE Brand complete gasket/o-ring kit. Are Vesrah parts really that good and worthy of the primo cost?

Thanks for the reminder on re-torquing in sequence the cylinder head nuts. The only really loose bolt was the one that holds the cam chain tensioner, the one above the adjuster screw. There was a considerable amount of oil seeping out of that area and I was able to get about a quarter turn on my ratchet. As for the cylinder head nuts, I managed to tighten down only the four corners of the cylinder head since there was oil weeping only slightly from those areas; having to remove two of the spark plugs to get access to two corners. The leak seemed to be gone, according to the nifty baby powder trick. But I'll definitely go around and tighten them all, in sequence, and within spec as you say. Thank you for that reminder.

Do you also think it's possible that the gasket(s) may have swelled a bit from the leaks?

[minimo]

The o-rings here are OEM and I have isolated the remaining slight leaks to come out from both sides of these cylinder head side covers
It's like I need thicker and more robust versions of these o-rings.

I cleaned out the recesses where these o-rings plug and there was some carbon-like debris and schmutz that was easy to scoop out.

Time to reorder 4x O-RING, 6x3 HONDA part # 91319-323-000