'81 GL1100 - Smoking left side, starts clear then gets worse

[sacruickshank]

A follow on question on the GL1100 resurrection. 19k miles, but has been sitting for probably 20 years.

Before manually turning any cranks, I soaked the cylinders first with PB Blaster and then with diesel. Hopefully that unstuck things, but I haven't yet peered inside with a scope

I have cleaned the carbs clean, set valves, etc. so she starts right up idles fine. The exhaust is clear to start, but the left exhaust gradually gets greyish over several minutes. The right side is fine. I recently replaced the valve seals as a first attempt at fixing it, but the smoking still occurs. I also see some light smoking from the engine/cylinders/exhaust headers.
I checked the carb plenum about 15 minutes after the most recent test and it was fine, so I don't think the valves are causing an overflow. I'll look again immediately after shutting down the engine.

Any suggestions on what to check next? I've read some options might be oil ring on the pistons, but also heard that requires major effort, splitting the cases, etc. do I'd rather try something simpler first. Could the head gasket be the source?

Any other ideas?

Thanks

[2003Cobra]

I think the next thing I would do is a compression test and see what each cylinder is doing. That would tell you the overall health of the engine. If you have a cylinder down then Borascope it and see how it looks inside. Be sure to read your plugs when you pull them.

[sacruickshank]

Already did the compression test, 165-170 for all four. Should have mentioned that.

Pulled the LH plugs today, #2 was normal but #4 looked a little dark. It wasn't wet/oily, but it wasn't whitish either.

Haven't scoped the cylinders yet, but got a peek through the intake manifolds. Walls "look" ok, although there is (or at least was) some brownish residue just beyond what I assume to be the top of the piston stroke.

Next check is the engine bolts, make sure they're fully torqued.

[Maz]

Could also just be some residual PB blaster/diesel etc in the exhaust system. As the exhaust warms up after a few minutes, it's burning off. Might be worth letting it run til it's fully warmed up and seeing if it clears.
Maz

[sacruickshank]

At this point, I doubt it's residual PB/diesel. It's been thru 3-4 test starts so far, with one of them lasting until the cooling fan kicked in. I could be wrong as I've done other bikes that definitely took a long time to blow out all the crud. I've also pulled off the exhaust and knocked any loose crud out. I thought that me the cause since the exhausts were a critter food pantry.

Next test is to re-torque the cylinder bolts and test start again.

[virgilmobile]

Don't discount what Maz mentioned.
When I restored my 88 from the flood I had diesel in the exhaust.I fogged up the shop for a week everyday and 3 more 5 mile runs before it started to diminish.It finally quit after a week of running it 10-15 miles every day.
That diesel soaked into the rust inside the exhaust and started smoking when they got hot.Seemed to take forever to get it burned out.

[sacruickshank]

Good data/point. I previously had a '79 cx500 that took multiple 15 minutes sessions with billowing smoke before it finally cleared. I'll run several more sessions before taking the cylinder heads off. Unfortunately, she's not road worthy due to ancient tires and no headlight (still in the Vetter fairing that came on the bike as shown in the profile pic), so I can't ride it out until I invest in some new rubber and get the lights sorted.

Interesting you mention the diesel flooding. On a previous project I saw your story and used the idea on a stuck starter sprag clutch by flooding with diesel and kerosene. Didn't work, but made for an interesting garage pics as I had the 'wing in a permanent wheelie by putting the front wheel on my lift in order to get the diesel down to the sprag.

[virgilmobile]

My 88 was submerged under 4 feet of flood water for 2 days.I drained the oil/water and filled the entire engine cavity and carbs with 7 gallons of diesel to protect it just days after I got it out of the shed.I started the restore 3 months later.
3 years later the bike still runs great.
I'd still suggest that you fog up your shop several more times.Get the exhaust hot to burn off the residual oil.
I did mine at night so the fire department wouldn't be called so often.
I told them it was my mosquito abatement program.

[sacruickshank]

Great news. Smokie ran for about an hour last night, with consistent billowing smoke.

At today's start up she ran clear for 10 solid minutes, then started a faint smoke some time before the 15 minute mark. Still smoking at 20 minutes, but light enough that you could ride without the smoke being noticeable when moving.

Smart money says it'll run clean soon. I'm psyched and thanks for the guidance to let her burn it off. Saved me tearing into the engine again and potentially mucking things up.

[virgilmobile]

Ride it like u stole it.