One head gasket, or both?

[kerryb]

I bought an '83 interstate for $300. The op said it uses oil, and he was not going to be riding anymore due to upcoming ankle surgery. I saw the white smoke as soon as it fired up, so I knew there were head gaskets in my future. I also saw the evidence of going down on the left side while moving, but didn't realize how badly the fairing was broken till I got it home, ...so we're going naked! The speedo said 30k miles, which I was sure was 130k, but decided what the hey, lets go for it. A compression test was in order before any serious work just to get a baseline, and that's where it got really interesting...#1 180psi, #2 132 psi, #3. 180psi, & #4 181psi !!! Maybe it really is only 30k miles, this might be a keeper. So now the questions start. Why is it using oil? The plugs were oily, are the valve stem seals old and perished? With compression that high, the valves must be sealing okay. Should I do both head gaskets? I know one side failed, but attribute it to the crash bar hitting the belt cover and breaking the edge of both the front and rear belt cover. Should I pull the other head just to change the valve stem seals, or try doing it with compressed air and leave the gasket alone. Of course the belts will be changed before running it much, all I know about the belts is I don't recognize the name on them!
It's all part of the adventure...

[pidjones]

Change the belts before riding ANY more. Stem seals can be changed by feeding a ~1/4" rope into a plug hole and jambing it against the valves with that piston. These bikes seldom use oil. Also, try another compression gauge.

[cfairweather]

If you are going to keep it and want to do a good job, consider doing the following:
1. Remove both heads, take the valves out and clean the heads, valves, etc. Also clean the water jacket around the cylinders.
2. Lightly lap the valves and check to see if any have excessive play in the stems and my guess is they are fine.
3. Replace head gaskets and all seals, including the ones at the end of the cams.
4. Replace the water pump. Chances are, this is the original and while you have easy access to the bike it is worth replacing it.
5. Replace the belts and you may need to replace the idler wheels.
6. Rebuild the carbs.
7. Do a complete service of the bike: Change all fluids, flush radiator, grease, and carefully inspect the bike. Replace/repair anything that needs attention. One thing that gets ignored is the triple tree bearings so clean and grease these.

[redglbx]

Myself, I would do the belts immediately as I replaced only the bad head gasket ! I believe why replace a good head gasket that may (it’s all a guess) last the life the bike with one that may be of less quality. There is a lot of opinions and debate on what is right, flip a coin.

So if it were mine I’d replace the single head gasket after thorough cleaning and a light lap of the valves, change the belts and the brake fluid, really all the fluids. Take a look at the brake pads, then if it runs fairly good I’d put fresh gas along (look at the tank for heavy rust) with some carb cleaner and just ride it for a while paying close attention to things for leaks or other problems. These bikes seem to be quite robust so it may not really need much to enjoy it, but as I said pay attention, I always give mine a good inspection every time I clean it, always looking for problems. That’s my .02.

[kerryb]

Change the belts before riding ANY more. Stem seals can be changed by feeding a ~1/4" rope into a plug hole and jambing it against the valves with that piston. These bikes seldom use oil. Also, try another compression gauge.

I have only run the engine for about 3 minutes total so far, and I wont run it again untill the belts are changed. I will see if I can locate another compression tester to try. Mine is fairly new by Sears Craftsman, but I thought stock compression was only about 171psi.
Now, about that oil...there is a small pool of oil in the carb plenum! Been thinking of ways it could get there. The oil sight glass is over-full, as I haven't drained the fluids yet. Could it be possible that the oil got pushed up the crankcase vent? Or, is it more likely the engine was running as the bike laid on it's left side after the crash, and that's when oil went up the vent tube to the airbox? (Oil is very clean) I'm still peeling back the layers to see what I've got, debating weather to tear the forks down to check straightness of the tubes (seams excessive, seals aren't leaking). This is almost as much fun as riding my other wing!

[kerryb]

Here it is...

[gltriker]

At least a year ago, there was a report of oil being discharged out of a running GL1000 engine's crankcase breather fitting.
The complaint was extensively discussed and we never confirmed whether the crankcase was grossly overfilled, but logic seemed to point in that direction.
Although he resisted and blamed it on a restrictive oil filter, I don't remember whether the actual volume of oil in that engine was ever reported when the discussion, abruptly stopped.

I believe whiskerfish had encountered an engine with a significant amount of pistons' to cylinder walls' clearance blow-by into the crankcase that exhibited a similar movement of oil misting from the breather towards to air filter housing.

In either case, it would surely have wetted the air filter element on its way into the air plenum.

I had been surprised at several 180psi compression test results and one cylinder at 130ish; all with oil on the spark plug tips?.

A cylinder leakdown testing session, at least on the lowest compression tested result cylinder might be fruitful. ?

I just noted this GL is an 1100. I have to assume the crankcase breather vents into the air filter housing similar to the GL1000 breather plumbing?

[redglbx]

Kerry, if you indeed have a blown head gasket it is probably allowing coolant into the crankcase which is pretty common. The coolant will sit on the bottom of the crankcase and the oil will float on top and as the coolant goes in, it will overfill the crankcase.

A normal tell on this is the oil will be foamy and may look like a chocolate milkshake, I would drain the oil & if it has water or coolant in it do not run it until the problem is fixed, coolant in the oil will damage the engine bearings so it needs to be fixed if that is occurring. If the oil is foamy or the crankcase is overfilled it will get sucked up the breather and into the air cleaner.

[DUGG]

As a professional auto mechanic I would never do just one head gasket. If one has failed the other is just as old and my fail soon or already be failing. Plus the amount of work it takes to do the second one usually isn’t that much more time vs having to go back in a second time.
An over filled crankcase will force oil out of the seals and breather system. And will cause excessive exhaust smoke. You my want to start with changing the oil first.
Coolant/oil intermix is rare in my experience when a head gasket fails.

[Sidecar Bob]

If one cylinder's compression is that much lower I think I'd start by checking the valve clearances, particularly on that cylinder (valve clearances that are too much below spec can prevent the valves from fully closing).

How much smoke are you seeing and are you sure it is white and not light gray? A bit of light gray oil smoke is common on 4 cylinder 'Wings on cold start, especially on the left side after it was parked on the side stand. See this thread:
https://www.ngwclub.com/forum/viewtopic ... 17#p802017

Oil consumption is often the result of slightly overfilling the crankcase.
I always assumed the oil should be filled to the upper line and topped up when I checked it few hundred Km later and the level was halfway between the lines because that's what had happened on all of the bikes I'd had.
One day I read something about inaccurate dipsticks on some old Hondas and the GL500 I had at that time (in addition to the '83 'Wing with '79 GL1000 engine) had a dipstick so I decided to check it by adding exactly the amount of oil the manual specified at the next oil change. I was surprised to see that the recommended amount did not fill it to the upper mark but halfway between the lines so I decided to try it like that and keep an eye on the level. The oil level still gradually lowered but it was still well above the lower mark when it was time for the next oil change.
So I did the same with the GL1000 engine at its next oil change with exactly the same results.

A few years later I replaced the 1000 engine with an '82 1100 (long story involving overall gearing and the sidecar). Because of the sidecar the bike is always close to upright when parked and it still smokes enough to clear out mosquitoes for half a block the first time I start it after sitting a few days BUT I still don't need to add oil between oil changes.

As for whether to change one or both gaskets, I'm with red on this: Why disturb the other one if it doesn't have a problem?

[kerryb]

Ok, lots of comments while I was away, so here's the plan. While I wait for parts to address known issues I will; collect the fluids I drain for analysis of volume and content. So far, the oil looks good, not milky, and the coolant level is down but looks about right ( there is an inch left in the reservior).
Haven't decided on one or both gaskets yet. I figure the one that failed was due to accident damage/shock, but it sure would be a shame to tear it down again if the other one fails soon,...hmmm.
Right now I'm wasting a little time trying to mount a viper fairing from the stash so I still have a small windbreak and dont have to source a headlight bucket as I'll use the headlight mount from the crashed fairing. Then, choose some turn signals.
Stay "tuned" for progress reports.

[Sidecar Bob]

Do the testing before you worry about whether you need to replace one or both of the head gaskets. A couple of years ago I had no choice but to replace both
https://www.ngwclub.com/forum/viewtopic.php?f=1&t=73408

[Mike-C]

Kerry;
As this is the first teardown, I would do both head gaskets and a the valve stem seals to 'base line' the engine. Lap the valves while you are at it. Then you have a basis to work from.
Mike Coleman
'84 Wing-Lite (ex-Aspencade)
'84 (un-Terstate)
'84 Standard (as yet un-named)
'96 Kawasaki Vulcan 1500 (The Vulcanator)
'03 ST1300 Pan-Tastic

[redglbx]

As several have commented above it is normal for these bikes to smoke on startup. My red 76 has done it since new and was quite a learning experience. Honda has worked to eliminate this but I have seen even new1800’s do it for whatever reason, doesn’t seem to hurt anything (not good for the cats on the new bikes). Now with that said, the only time my red 76 has used oil is when I neglected to reconnect the breather hose back to the air cleaner and then it went through a lot of oil on a 350mi trip where I had it running at 4K plus rpm’s for extended periods, the oil level was below the sight glass. Scared the heck out of me because I figured that something must’ve broke to use all that oil.

During the inspection I found the hose off the air cleaner and after plugging it back in I inspected the oil regularly for the rest of the weekend and ride home, it hasn’t used a measurable drop since. My thoughts are that having the hose plugged in and a good separation can ( have you ever serviced yours ?) provides a small amount of vacuum in the crankcase that’s keeps the rings from “fluttering” that allows oil to get by the rings and burn in the combustion chamber. Having the breather plugged into the air cleaner & functioning is a must have thing imho.

Now I know that the various years have different breathers but they must be working. So if your bike uses oil check to make sure your crankcase has a vacuum on it.

[Rednaxs60]

You mention the head gasket is gone on the one side. Before removing the head and such, I would recommend having a look in the cylinder for any sign of oil/coolant fromt eh side you suspect. You can get a small, inexpensive borescope that syncs to a cell phone to have a look throught the spark plug hole. May answer a question or two. May be able to orient it to see the valves as well. You will definitely be able to see the cylinder and piston.