Rebuild Time? Need input..

[Diskman01]

My 78 1100E has always burned a bit of oil.

Compression test tonight. Warm. Dry cylinders. Open throttle:

1 - 179PSI
2 - 179PSI
3 - 165PSI
4 - 179PSI

Cyl #3 seems to foul the spark plug quickly and I assume that is where my oil burning is coming from.. I tossed a tablespoon of 5w30 oil into #3 and the compression shot up to 200PSI.

What are the chances I can just hone the bores and toss in some new rings? I heard that oversized pistons are impossible to find.

Any ideas on how far I need to go down this rabbit hole??

[natemoen]

They are within tolerance, leave but alone.

That is my input. Plus I do not think that is your oil burning problem, those numbers are higher than the factory specs.

How much oil does it burn? Does it smoke? If so, when does it smoke?

[CaptonZap]

Burning oil can be caused by a number of things, and one of them is the oil return holes in the oil ring grooves get plugged with carbon.
You might try a shot of Marvel Mystery Oil in the crank case for an oil change. Be sure to use 50 wt oil, and add MMO according to the directions on the can. It has solvent properties, and can work minor miracles. Such as freeing sticking valve lifters, which we don't have, but does show some of it's abilities.
Do not flog the engine too hard during that period, and use a lot of engine slowing, (backing off the throttle), to hopefully help the caked carbon get dislodged. If that isn't the problem, the MMO will provide you with upper cylinder and valve stem lube.
CZ

[3Phase]

What are the chances I can just hone the bores and toss in some new rings? I heard that oversized pistons are impossible to find.

There's a pretty good chance, actually, unless something messed up a piston or a cylinder bore.

Any ideas on how far I need to go down this rabbit hole??

How deep you go down the hole sort of depends on how much you really like rabbit.

The miles on the engine, how it's been ridden and maintained along with a pot of luck tossed in for good measure will get you to the table on time for tea but there's no way to even begin to guess until you at least pull the cylinder head and look at the pistons and bores.

You'd have to split the case to check the crankshaft main and rod bearings --take the blue pill.

.

[Diskman01]

They are within tolerance, leave but alone.

That is my input. Plus I do not think that is your oil burning problem, those numbers are higher than the factory specs.

How much oil does it burn? Does it smoke? If so, when does it smoke?

I went on a 1000 mile trip last fall (2013) and usually used 1 quart every 2 fillups or 1 qt per 220 miles or so. Interstate (75MPH) driving seems to make the bike thirsty for oil. Even with an 850FD swap to keep my RPMs down.

Can't really see smoke. Can REALLY smell it if I put the fairing on. It DID cover the saddlebags with thick oily exhaust during that trip tho.

Planning on some head work also.

I was surprised at the high compression numbers also. They DID go up from 165 each since I bought the bike in 2011. Except for #3.

Would adding some oil in #3 with good rings really make it shoot up to 200?

Is it normal for a cylinder to gain 35PSI when oiled?

Lots of questions... lol

[Diskman01]

There's a pretty good chance, actually, unless something messed up a piston or a cylinder bore.



How deep you go down the hole sort of depends on how much you really like rabbit.

The miles on the engine, how it's been ridden and maintained along with a pot of luck tossed in for good measure will get you to the table on time for tea but there's no way to even begin to guess until you at least pull the cylinder head and look at the pistons and bores.

You'd have to split the case to check the crankshaft main and rod bearings --take the blue pill.

.

Engine just turned 40K miles. Not sure on POs.. At some point, someone threw some $$ at her. New voltage regulator and some wiring at the original (now replaced) fuse block.. Some other things were done wrong tho.

Not too keen on splitting the case. Bike runs great. No knocking or other oddness. Just using more oil than I like to see.

Ill probably pull the head this weekend and see whats up..

[MPittma100]

Rebuild?

If you suspect #3 cylinder has a problem, you should leak test it to see where/if the leak is. You do not want more than 15% leakage. If there is
more than 15%, or if it is a good amount more than the other cylinders, you need to determine what exactly is causing the leak - rings, valves, head gasket. Once you know what is causing a leak, you will know what you need to fix. This is a much better procedure than guessing.

With that (165) number, the cylinder appears to be ok even though not necessarily in line with the others. These bikes use oil normally and do not smoke. The amount you will use is determined by how hard you ride. If you are producing oil smoke, that may be a different rabbit.

If the plug is oil fouling with good compression, that would tend to indicate worn valve stem guides and/or oil seals. Plug fouling may be caused by fuel instead of oil?

Determine how much oil you are actually consuming before you decide how much of a problem (if any) that you have.

Mike

[Eveready1100]

Hi Diskman,
You haven't given us a vital piece of information yet, mate. What oil are you running in the motor?
Mine was going through a lot using 15-40 weight, but since I switched to the 20-50, oil consumption has reduced quite a bit (if I'm behaving myself)

BTW, Ringsets are normally readily available on the bay. Just do a search.

[ViperRon]

The issue is burning oil and normally there are two things that cause oil usage. One is rings but you have good compression numbers so since rings usually wear even or compression wears at least more than Oil rings the chance that your oil issue is rings is slim to none. More than likely the issue is valve guides or oil seals. You could take carbs off and look into intake and exhaust off to look into exhaust valve ports. I would bet you have a lot of build up in one cylinders valves. Just because you see build up on exhaust does not mean it is the exhaust it could be the intake. All it would take is a worn, loose or crooked installed seal or a worn guide. One other issue could be a slightly bent valve that wears the seal and guide abnormal. It may seat ok not loosing compression but wobble enough to like I said wear the seal and or guide.

Now there is another issue where your carbs are allowing gas to leak into the crankcase. The gas causes oil to foam and it is sucked back into air box threw carbs and burnt there. Make a close check on your oil and check the air filter for oil film. If you have pods then it still can pressurize and force the lighter foam out the breather vent and if you have a hose leading it down to ground you will never see it.

Another common issue with these bikes is the crankshaft oil seal. I know the one under the timing advance can go bad and it will leak badly when up to temp and running and you will not see it dripping when running down the road. So a good thing to do is run it till it is warm then park it on side stand and let it idle there for several minutes. You can either take the cover off looking for oil or set it on the center stand and watch for a puddle.

These issues can also cause performance tuning issues that make you think the bike has compression problems. I would look anywhere but into cylinders and rings.

[Diskman01]

Hi Diskman,
You haven't given us a vital piece of information yet, mate. What oil are you running in the motor?
Mine was going through a lot using 15-40 weight, but since I switched to the 20-50, oil consumption has reduced quite a bit (if I'm behaving myself)

BTW, Ringsets are normally readily available on the bay. Just do a search.

I use Valvoline Motorcycle oil 20w50. Non synthetic.

[Diskman01]

Wow. Thanks for all the info guys! I think a head refresh is in my near future at this point.

Any suggestions on who to look for to do the work? I had an automotive shop years ago that did head work on my Jeep. Is this something I need to find a specialist to do? I can install the seals, but pressing in guides and seats is beyond me.

[MPittma100]

Head

Wow. Thanks for all the info guys! I think a head refresh is in my near future at this point.

Any suggestions on who to look for to do the work? I had an automotive shop years ago that did head work on my Jeep. Is this something I need to find a specialist to do? I can install the seals, but pressing in guides and seats is beyond me.

The (automotive) machine shop that I use will: 1) Glass bead the casting and valves 2) Grind valves and seats 3) Assemble head with new seals and adjust valve lash. He adjusts lash by slightly grinding the valve tips. The head is ready to reinstall and no further adjustments are required.

You will need to take the cams and caps to the shop along with the head.

I suggest calling around to get the right shop.

Mike

[Diskman01]

Wow! Its been 2 years already. Let's dig up this old thread just for kicks this fine afternoon!


November 2014 I pulled the head after ordering new valve seals. The original seals were cracked and VERY hard. Ordered new viton seals off flea-bay.

The carbon buildup on the head and valves was IMPRESSIVE. Took a few days of B12 Chemtool, carb cleaner, scotch-brites, laquer thinner and a can of old Permatex Gasket Remover to remove all the carbon. It was NASTY.

Anyway, replaced the seals, re-shimmed some buckets that needed it and re-assembled. Ran like a champ! No more smoking.

Well worth the time to replace the seals.