Valves got louder then BAM!

[duaneage]

i'd say your situation with a toasted engine sucks, but not totally...

why not take cafe kids offer for parts and rebuild that engine yourself?
parting out the whole bike, advertising, wrapping parts for shipping, trying to sell of those few last bits noone seems to need, etc... is a lot more work than rebuilding the engine and you''ll end up just covering your $ losses and having no bike in the end

while a few extra hundred bucks should see that bike on the road again and a grin on your face for everything you've acomplished :-D
worth it, i think

TCK doesn't have a 16V engine so it's not that easy. But there are others on the GSR that might be able to help

He should post it in the classified section here under parts as a rolling machine in need of engine and see what happens.

As a starving student your clearly not in a position to repair it so your going to be off the road for a bit. But there are plenty of GSes out there.

 

[Guest]

TCK doesn't have a 16V engine

well, he says he does... read his post above

 

[82Shafty]

Bleeble,

My best advice is to source another engine/tranny.

I've seen 1100L engines go for 300 bucks in running condition. I would certainly think you could find a 750 for a reasonable price.

One, you need to spend time studying. At some point in the future you could get yourself 300 scratch to get your bike on the road, but rebuilding the stuff takes the proper equipment, time and materials.


If your valves got louder and a piston locked up, sounds like she either barfed the oil pump or was low on oil as you mentioned she burned oil. When the valves get too hot they will start to hang up causing a louder tick and if there isn't any oil being splashed up onto the cyl walls especially the inner cyl, then you're SOL.

 

[bleeble]

Bleeble,

My best advice is to source another engine/tranny.

I've seen 1100L engines go for 300 bucks in running condition. I would certainly think you could find a 750 for a reasonable price.

One, you need to spend time studying. At some point in the future you could get yourself 300 scratch to get your bike on the road, but rebuilding the stuff takes the proper equipment, time and materials.

If your valves got louder and a piston locked up, sounds like she either barfed the oil pump or was low on oil as you mentioned she burned oil. When the valves get too hot they will start to hang up causing a louder tick and if there isn't any oil being splashed up onto the cyl walls especially the inner cyl, then you're SOL.

Time is not a problem, just money. I don't know if it's cost-effective to do an actual rebuild. Taking a quick look online, it looks like piston rings, bearings, gaskets, etc. would add up fairly quickly. Frankly, if I'm going to do it, I'm going to do it right. I won't replace one thing then put it all back together, ignoring all the things I should have replaced while I had it apart.

I don't know if you read the whole thread, but it appears that the problem is most likely a broken connecting rod. The oil level was actually the first thing I checked after I stopped (it was good). I didn't perform a thorough inspection, but the valves appear to be fine.


Can I get to the crankshaft/rods by dropping the oil pan?

 

[Dave8338]

No good for sure! I agree with Shafty in the fact that is was a lack of oil that caused the situation in the first place. The valve train is the first thing to show oil deficiency and will likely be shot! Also, as the #2 rod (for whatever reason (seized bearing)) parted company with the piston, cylinder and crank damage are all but guaranteed.

Look for a complete engine to swap in and either ride it or sell it as a complete running bike. Point out all the things that you've done in the form of upgrades and the like and get your money back out of it.

An engine run dry (for whatever reason) is seldom worth rebuilding. Scrap that part of the bike. My .02 cents...:?

 

[80GS750]

i say, tear it off the bike and then take it all the way apart... then take some time and do some research and then you will know what will work out best for you, a rebuild or a new engine

 

[bleeble]

Yeah, I'm still not 100% sure what the problem is yet. I'll have to take things apart to know for sure. If it's not too much trouble or too expensive, I'll probably just fix it and ride it.

The good news is that I just got a letter from the IRS letting me know my stimulus payment (and hopefully refund) should be along shortly. Good timing. Gasket sets and engines tend to be expensive.

 

[catbed]

if i were you, i'd pull the engine, take it apart, and fix it. sure it may take a long time with your money situation but you'll learn a lot about motorcycle engines and possibly have fun. i would love to rebuild an engine.

 

[Dave8338]

you'll learn a lot about motorcycle engines and possibly have fun. i would love to rebuild an engine.

Alrighty then, Bleeble...send catbed yours and you'll both come out winners! Problem solved! \\/

 

[TheCafeKid]

TCK doesn't have a 16V engine so it's not that easy. But there are others on the GSR that might be able to help

He should post it in the classified section here under parts as a rolling machine in need of engine and see what happens.

As a starving student your clearly not in a position to repair it so your going to be off the road for a bit. But there are plenty of GSes out there.

I DO have a 16v motor. The top end is toasted. The lower is fine, as are likely the pistons, and maybe even the jugs. ( I would bet so) I have NO USE for the motor, as i dont care for the 16v motors much (there are a couple of the bigger 16v GSs i wouldnt mind owning) So I HAVE THE PARTS.

 

[bleeble]

I DO have a 16v motor. The top end is toasted. The lower is fine, as are likely the pistons, and maybe even the jugs. ( I would bet so) I have NO USE for the motor, as i dont care for the 16v motors much (there are a couple of the bigger 16v GSs i wouldnt mind owning) So I HAVE THE PARTS.

I'm curious: What is it that you don't like about the 16 valve motors?

EDIT: Should I even bother removing the cylinders?

 

[TheCafeKid]

I'm curious: What is it that you don't like about the 16 valve motors?

Hrmmm well let see. You have a dead one in your bike, likely because it wasnt getting oil. I have a dead on on my bench, surely because it wasnt getting oil. They also have plain bearing cranks. And to be frank, i think they are ugly looking. But, thats entirely just me.

 

[Griffin]

Well I like the 16 valve motors better than the 8 valve motors, so there!

Actually, the second generation GS750 ('80-'82) has a pretty good track record of reliability. I think the toughest GS motor ever made is probably the original 8 valve GS550 though.

You should be able to find a decent used 16 valve GS750 motor fairly cheap. For the GS series, it was second only to the 8 valve GS550 as far as numbers imported to the US go.

I can check at Cycle Recycle II here in Indy for you. He's got about 50 old air cooled inline four engines in the back room.

 

[rapidray]

Listen Bleeble, I build & rebuild GS motors ALL the time & if money is the issue just buy another motor. It can EASILY cost you $600.00 to 1000.00 to rebuild your motor CORRECTLY. You can find used 16 valve 750 motors all day long for $300.00 or less. If you have the money & the time, I say BUY ANOTHER motor as the one you have STILL needs too many parts replaced! You can also bolt in a 16 valve 1100 or 1150 motor you know! Good luck whatever you decide, Ray.

 

[bleeble]

The biggest issue I'm going to have with buying another motor is transportation. I doubt my little I30 is going to fit a motor in the trunk. Even if one does fit, I don't know how in the world I'd get it out by myself.

If you have the money & the time, I say BUY ANOTHER motor as the one you have STILL needs too many parts replaced!

This is what confuses me. I haven't even opened the darn thing and everyone keeps saying things like "Oh, X, Y, and Z are toast and need to be replaced. Your valves weren't getting enough oil, that's why your connecting rod broke. etc." :roll: I mean, I really appreciate all the suggestions and advice, but where are you guys getting this information?

Griffin, I may take you up on that offer. If you happen to be out there anytime soon, see if you can spot a good deal on an '80-'82 750 for me.

 

[Dogma]

...
This is what confuses me. I haven't even opened the darn thing and everyone keeps saying things like "Oh, X, Y, and Z are toast and need to be replaced. Your valves weren't getting enough oil, that's why your connecting rod broke. etc." :roll: I mean, I really appreciate all the suggestions and advice, but where are you guys getting this information?...

So, uh, when do you think you'll get to open it up? I'm curious to see which of all these speculations is correct. 50 brownie points to the winner!:-D Still, it's hard to think of something that could stop the engine like that without thrashing it, whatever the cause was. Especially since the stop was preceded by sudden mechanical noise.

 

[bleeble]

So, uh, when do you think you'll get to open it up? I'm curious to see which of all these speculations is correct. 50 brownie points to the winner!:-D Still, it's hard to think of something that could stop the engine like that without thrashing it, whatever the cause was. Especially since the stop was preceded by sudden mechanical noise.

I'll be spending the night doing the studying I neglected today and I have class all day tomorrow. So possibly on Wednesday. Friday at the latest.

 

[TheCafeKid]

The biggest issue I'm going to have with buying another motor is transportation. I doubt my little I30 is going to fit a motor in the trunk. Even if one does fit, I don't know how in the world I'd get it out by myself.


This is what confuses me. I haven't even opened the darn thing and everyone keeps saying things like "Oh, X, Y, and Z are toast and need to be replaced. Your valves weren't getting enough oil, that's why your connecting rod broke. etc." :roll: I mean, I really appreciate all the suggestions and advice, but where are you guys getting this information?

Griffin, I may take you up on that offer. If you happen to be out there anytime soon, see if you can spot a good deal on an '80-'82 750 for me.

Well, I get my information from both experience and sensibility. Just tonight i was working on an 8 valve motor that was only firing on two cylinders. But guess what? It was running. It didnt make a bunch of clatter and then slam to a halt. The only thing that can really do that is lack of oil flow or a spun/seized crank (usually do to lack of oil flow:-D) . The pistons will move up and down all day long as happy as you please, firing or not, untill the unburnt gas dilutes the oil to the point that it no longer lubricates properly, or they cease to get oil. Im personally not even sure its a connecting rod, wrist pin, snapped crank or anything else. The only thing i am pretty sure of is that your motor wasnt getting oil somewhere, likely causing the piston to sieze in the cylinder and break whatever is broken.


Im not proclaiming to be all knowing about these motors or any motors, but I can take a semi educated (only from experience ) guess on whats going on. Tonight however, I am stumped on this particular project, so who do i turn to for advice? You guys...lol Ive successfully learned how to strip and rebuild the top ends on these things by thumbing manuals and mostly by the eons of experience from those on this board, so when they talk, I listen. I may not always agree, or even explain things well enough for THEM to state thier thoughts, but i listen.

 

[bleeble]

Sorry I snapped at you guys before. Frustrating day... anyway, I had my digicam out so I thought I'd snap some pictures. Let me know if you see anything horribly wrong because I have no idea how things are supposed to look. \\/

(pictures in following posts)

 

[bleeble]

Pistons

Cylinders 1 and 2

Cylinders 3 and 4