70 psi on cylinder. #2, missing, fouling plugs

[beachbum3478]

i found a guy near me that has a 82 gs1100gl parts bike that he is selling for 100 bucks with a clean title. im mostly interested in the engine because most the parts are missing (seat, tank, gauges). but he said the engine would run that it just misses real bad and fouls the plugs in cylinder #2. and that cylinder 2 has 70 psi compression. what kind of problem does this sound like? i mean i know i should get it no matter what because engine parts alone would make more the 100 dollar asking price. i just want to know what im up against if i want to have extra running engine. thanks.

[bwringer]

Fouling #2 is the classic sign of a dying petcock. (After 20 years of aging, the vacuum diaphragm develops microscopic holes, which allows #2 where the petcock vacuum line is attached to slurp in extra bits of gas.)

It's conceivable that this cylinder is simply carboned up to the point where the valves don't close properly.

It's also conceivable that there was enough extra gas in this cylinder that it washed the oil film off the cylinder walls and caused the ring seal to fail.


Can you repeat the compression test with a bit of oil dumped into the cylinder to see if it's the rings?

[SqDancerLynn1]

If it's anywhere in So Ca ? I would buy it sight unseen

[beachbum3478]

no i wouldnt be able to do another compression test unless i bought it. the guy whos selling it did one at one point in time. but he just wants to get rid of it quick and doesnt want to fool with it anymore.

[TheCafeKid]

Snatch it up! at worst if you have to rebuild it, you still have a running motor to keep you on the road, so if it takes some time and money, you wont be pressed to get it done quickly.

[beachbum3478]

ok iv decided to get the bike, but i have one problem. i have no truck to it up, just my good old chrysler lebaron haha. the guy said its cool if i wanted to strip it down at his house. my question is, whats involved in removing the engine?, with the driveshaft still attached. thanks.

[beachbum3478]

is it just a matter of unbolting the engine mount bolts? i went out to my gs1100 and i think i found 8 that are holding the engine in. are there anymore that are hiding anywhere?

[Dave8338]

:?

is it just a matter of unbolting the engine mount bolts? i went out to my gs1100 and i think i found 8 that are holding the engine in. are there anymore that are hiding anywhere?

Go to your local "rent it" shop and rent a truck. If you strip the thing at his house, I can all but promise you that lost pieces / parts will be the result. Shock and swing arm bolts are all that is holding the rear end in the bike...an easy removal. Up to you...

[BassCliff]

Go for it

Mr. beachbum3478,

I concur with everyone's thoughts here. For a hundred bucks, grab it! Rent a truck or rent a trailer, and get it home. Congratulations on a nice find. Can't go wrong at that price, even with the rental.

Thank you for your indulgence,

BassCliff

[nabrams]

I'm guessing from your lack of knowledge of what might cause low compression that you are a novice bike mechanic at best.
Now, I don't mean to discourage you from buying the bike, but be under no illusions about the amount of effort and time (and some money for parts and tools) that it will take to get the bike road-worthy (or even just to get the engine running reliably). You're looking at 30 to 60 hours of time and $200 to $400 for tools alone (besides any parts you may need).
As someone on one of these forums said about my "reality check" comments: "You're a real ray o' sunshine aren't ya - but, of course, you're dead right!"

[TheCafeKid]

This may indeed, depending on the final diagnosis, be very true! However, there is NO better way to learn than to just get in there and do it. Ask me how i know...lol At any rate. Yeah its gonna cost some bucks here and there, but you have a running motor now, no? So there's no hurry to get this one running. And it will be a tremendous learning experience for you. The money spent on tools is an investment as well, as at some point, even if you DONT purchase this motor, you may end up needing them for your CURRENT one. (knock on wood ya dont, but yanno how that goes) I still say go for it. Buy a few tools at a time, parts too, as money permits. Work on it over the winter or winters or what have you. Just my opinion.

[beachbum3478]

new to bikes, yes, but not to cars. i ended up just getting a u hual van and picked the bike up. after talking to the guy i found out a few things. he said when he used to drive it around, that once he got it up to about 6000 rpm, that he could feel the #2 cylinder start to fire and bike would rocket off. he didnt say how long he drove it like that, so i dont know if it was long enough for a ring seal to go bad. i dont plan on restoring the bike at all, way to many parts are needed. but the motor looks very nice. i just plan on fooling around with the motor this winter, maybe to get it running, then just sell it on ebay.

[bwringer]

You also have to disconnect the driveshaft to remove the engine... but that's moot at the moment.

Sounds like a very worthwhile find!