Help with a diagnosis

[niclpnut]

Went to take a look at a 1982 1100E that a friend of mine is considering putting up for sale.

He's having a few issues with the bike and asked my help.

A little background. Base gasket leak initiated top end freshen up. Replaced rings, honed cylinders, new valves seals, and valves lapped. The bike only had about 20k when it was opened up. He has put around 1k miles on it since. Changed the oil (used conventional, not synthetic around 25-50 miles after putting in the new rings, then ran another 500


Cold Compression: 135, 120, 110, 120

Wet test showed a notable increase across all cylinders.


He says he didn't really baby the bike after the rings were installed, but did try to keep it below 4k for the first 500 miles or so. After the 500~ miles he changed oil with synthetic, and adjusted valves.

It idles well when cold, but after heating up, it gets a bit irratic, with an rpm drop. Plugs looked pretty good and were not oily. 4 was running a bit lean. (think it just needs a sync)

Just started to notice a hint of white smoke, from exhaust with a hard pull on the throttle.

Also, when warm, there is an audible irregular metallic taping/rattling that is more distinct from around the left side around the level of the jugs. Doesn't sound like healthy valve taping

http://s1100.photobucket.com/albums/g418/niclpnut/?action=view&current=VIDEO0012.mp4

*My thoughts were that the rings haven't seated fully, and now with the synthetic, oil is getting by the rings and burning off some.


*As for the rattle, all I can think is that one of the bores is out of spec and things are getting loose as everything is heating up, and or one of the rings got damaged during install and is popping out of its slot?

Probably going to pull the jugs to take a look at the bores and rings this weekend, just wanted to get some opinions~!


Nic

[Nessism]

Those compression numbers don't seem too bad for a cold engine. Why not repeat the test using a hot engine so you can properly judge? There could well be something mechanical going on but I don't think this has anything to do with using synthetic oil. The smoke on start up sounds like leaking valve stem seals. Do you know if they were replaced when the engine was apart before?

[tkent02]

Went to take a look at a 1982 1100E that a friend of mine is considering putting up for sale.

What does he want for the bike, as is? I can use another 1100, I have engine bits sitting here ready to go into it.
Once the engine is opened up, I can't take it, as I would need to ride it to Colorado.

[niclpnut]

Valve stem seals were replaced.

Reason I had mentioned the synthetic oil is that it's recommended not to use synth oil for the break in/seating period, so I thought that might be an issue with the rings not having seated yet. I figured they would have seated by now. Guess I was really hoping for greener pastures than telling him he botched the ring job : / I want around when he did the work, so I can't confirm measurements.


I'll try to get back by his house later today and do a warm test.

[niclpnut]

What does he want for the bike, as is? I can use another 1100, I have engine bits sitting here ready to go into it.
Once the engine is opened up, I can't take it, as I would need to ride it to Colorado.

I might be the one to grab this one if he really will sell it after we've looked it over. He hasn't gotten a price figured out yet, but wanted to know if the issues it's having would kill a deal or not.

His father just passed, and he's having to clear out some stuff to pay bills and whatnot.

[tkent02]

Most likely the problem stems from not running it hard the first few miles after the rings were replaced. Read this before it happens again...

http://www.mototuneusa.com/break_in_secrets.htm

[niclpnut]

Thats possible, but I heard him a few times out when he first got the rings done, and he wasn't gentle

[Nessism]

Valve stem seals were replaced.

Reason I had mentioned the synthetic oil is that it's recommended not to use synth oil for the break in/seating period, so I thought that might be an issue with the rings not having seated yet. I figured they would have seated by now. Guess I was really hoping for greener pastures than telling him he botched the ring job : / I want around when he did the work, so I can't confirm measurements.


I'll try to get back by his house later today and do a warm test.

Maybe a bad hone job? Some guys use those hokey spring bar hones instead of a proper dingo ball hone. Not sure but I'm fairly certain that synthetic oil has nothing to do with the problem. It's an urban legend that synthetic oil is lower friction and keeps rings from breaking in properly. Lots of engines come with synthetic oil from the factory so that should tell you something right there.

[niclpnut]

Finally got enough time to look at the bike some more.

White smoke when warm, no smoke at start up.

Warm compression:

1. 150
2. 135
3. 130
4. 150

Wet, 2 & 3 go up to 150.


Probably going to help him pull the top end off this weekend if work schedule allows, measure everything, rehone the bores at a minimum and make sure no rings were damaged.


Nic

[Nessism]

Maybe the valve stem seals came loose or were damaged during valve install?

[niclpnut]

Got into the bike a bit today.

Pulled the top end and started to look over everything.

head is good. Valves seated well and no leaks. The stem seals are also doing their job. Stems are all dry.

Pulled the cylinders and found some scoring on the walls. More so on 2 and 3 confirming compression test leak:

Tried to see if I could hone them out but thinking it's a lost cause and an over bore or used cylinders are in order. This is after I gave them a hone:



Vertical score lines.

The rings all look good, and measure in spec loose. They appeared to be installed correctly on the pistons. Pistons show some scoring also:



I pulled a few rings to check end gap installed in the bores and for the most part they are on the tail end of the service limit.

I don't have an inside bore gauge but my guess is that the previous hone went wrong, and the cylinders are either out of round or out of spec.

I'll see if I can swing by a shop for them to mic them to be sure.

What else would cause the vertical scoring? Fuel mixtures off? Rings only have about 1k miles on them since the last installation.

Nic

[Nessism]

Scoring could be dirt ingestion, or dirt during installation. Not sure. You running pod filters?

Only thing left to do is measure the bores and piston to cylinder clearance and go from there.

[niclpnut]

Yeah, pod filters.

Trying to get down to a machinist I know with a bore gauge and we'll see.

Nic

[niclpnut]

bores all mic'd out to around 2.838" (72.085), and cylinder 1 being slightly more out of round than the others.


This appears to be the service limit, so I'm assuming a used low mileage jug or over bore is in order.

Nic

[chef1366]

Do an 1166 kit
He'll like it