Exhaust smoke, tapping noise, compression test

[jsandidge]

The tapping you hear could be from the exhaust leak.

[GS1150Pilot]

Can you helicoil a new stud in?

[Steve]

Can you helicoil a new stud in?

Need to get the broken one out, first.

.

[Joe Garfield]

Yeah I agree that plug 4 looks 'better' than plugs 1-3. Running lean/hot probably exacerbates things like popping and any other symptoms affected by heat. I'll try to tighten up the loose pipe (if I can't get the broken bolt repaired) and get the carbs synced/adjusted, and ride like a bat outta hell in between.

It sounds like I don't have much to worry about regarding piston rings and valve seals, so I'll check that stuff out next time I'm close to valve cover removal.

I still don't understand where all the smoke is coming from (and where all the oil is going) if the rings and seals are OK, but I trust the recommendations to give nature a chance at fixing it first.

Apparently I've finally found a hobby that works in all weather conditions. I've been enjoying some decent riding weather, and also excited for rain predictions so I can get back in the shop

[Dogma]

Speaking of rain in the forecast... Are you wrenching on it tomorrow evening? I might drop by to say hi.

[Joe Garfield]

Most likely - it seems the only thing I want to do these days is ride or wrench, and I've got plenty of projects to work on....

[Dogma]

It looks not like work is going to run late tonight. We'll see if I can get out.

It seems ridiculous to me that we had to go to Indiana to finally meet.

[Joe Garfield]

I tightened the loose exhaust clamp, torqued the engine mounting bolts (had some handlebar vibration), put things together and went for an 'Italian Tuneup' ride. At one point I was at a stop light and the tapping was really loud, to the point where I could basically feel it, and it was sort of cyclic (rapid taps, constant rate, but amplitude varying sinusoidally). I kept up the ride and it seemed to quiet down to where it was before. When I got home, the tapping sound was constant: if I listen near the left side valves, I hear what sounds like normal valve noise. If I listen on the right side, it's a similar kind of noise but much louder - like the valve is hitting as opposed to sealing. It could be a number of things so I don't want to say it actually is some kind of valve interference yet. The first 2 things that I did with this bike was bring the carbs to Steve and have him help me with valve clearance, so it could be something else (cam chain adjustment? although the adjuster was refurbished...)

I didn't get a good look at the exhaust smoke - it needs to be dark with a headlight behind me, and it was late so I didn't take the time to get out my maglite when I got home. It also wasn't a very long ride so I figured it needed more time before reassessing. I will say that this bike is a freakin' animal - at 6,000+ rpm in 2nd and 3rd I had to hold on pretty tight But it was very stable and no sign of vibration until 7000-7500 rpm (I cut back throttle as soon as I felt it, so I don't know what the exact number was).

[Dogma]

Can you post a video featuring the noise so the experts can hear what's going on?

[Joe Garfield]

Sure, I'll do that next chance I get.

I've been doing a little research and am starting to lean toward 'cam walk' as my hypothesis, or at least something related to cam walk. The 'synchronous' sound I heard when I was stopped at a light, and another peculiar noise I started hearing/noticing which I thought sounded like cards in bicycle spokes (but faster and quieter), so maybe the cam chain tensioner needs an adjustment and is allowing cam walk. This all makes me feel a little better - I can live with it as long as I know it's not causing harm (or can be fixed with a cam chain tensioner adjustment).

I'll do the RPM check and see if it goes away at 1200-1500 rpm...and take a video.

[Steve]

Next time you stop by, I'll fire up my wife's bike so you can hear what I KNOW is cam walk, then we can compare that to your noise.

.

[Joe Garfield]

Can you post a video featuring the noise so the experts can hear what's going on?

Here's a video. It's gotten much quieter since the 'Italian Tuneup'. There's a slight tapping which is probably normal valve noise. The phone didn't pick it up very well so I took a couple of videos, and this one I was actually looking more for smoke than sound, but it seemed to pick up the sound the best.

https://youtu.be/JyribgaolnY

[zuzu]

Is that smoke coming out of the breather tube from the breather cover? Which is on top of the valve cover.

[Dogma]

I think that noise is something in addition to the normal valve clatter, but I don't recognise it. Hopefully someone else does.

I'm wondering about the breather tube too. The passage where the breather feeds into the airbox gets clogged with rust, and can cause the crankcase to build positive pressure instead of letting the intake keep it at negative pressure. It's not the tube on the airbox where the hose connects, but the rectangular sheet metal box at the very top of the airbox interior. Anyhow, if this is blocked, blow-by smoke might escape a vent hose, since it isn't very tight.

Something is making the cam cover oily on the left side. If oil is pooling right on top of the head, it might get hot enough to smoke.

[Joe Garfield]

Is that smoke coming out of the breather tube from the breather cover? Which is on top of the valve cover.

I will take a closer look, thanks for the suggestion.

I'm wondering about the breather tube too. The passage where the breather feeds into the airbox gets clogged with rust, and can cause the crankcase to build positive pressure instead of letting the intake keep it at negative pressure.

That makes sense - the way the smoke comes out from under the tank seems like it's from more of a forced convection (fan or induced pressure) as opposed to natural convection (heat). It also has a bit of an exhaust smell, but I'm sure there's some burning oil residue mixed in there.

Something is making the cam cover oily on the left side. If oil is pooling right on top of the head, it might get hot enough to smoke.

I guess I need to take things apart and clean them up to really diagnose everything. Steve and I had the valve cover off when we did the shim adjustment, but I didn't have much time to get things cleaned up. This bike leaked oil profusely, mostly coming from the tach cable seal (which I refurbished). So the tach cable seal and valve cover gasket are new, the rest is still from the PO (breather cover gasket, head and base gaskets, etc).

If it wasn't riding season I'd happily take the bike apart, replace all the gaskets, clean the valves and replace the seals, get the bolt threads repaired, and probably have the engine cleaned (and maybe painted or Cerakoted). But with these long days "summer hours", there's hardly any time during the week to take on big projects, so it would take forever if I tried to do all that now.

I'll clean what I can, replace the breather cover gasket, try to find the breather hose airbox thingamajig, and see what I can find.

I think that noise is something in addition to the normal valve clatter, but I don't recognise it. Hopefully someone else does.

I guess I agree with you. I was trying to be positive and hope it was nothing unusual, but I know what valve clatter sounds like (I've been driving Nissan Frontiers) and this has a bit more of a metallic ring to it. I don't mind doing some work to diagnose and repair it, I just hope I'm not making it worse by riding.