750 TSCC Rebuild or Replace?

[storm 64]

Oh boy, I have to clean the garage/shop, I have company coming over tomorrow! The engine doesn't look to bad. I sprayed it with grease before I put it into storage. Downside of that, it's a greasy mess. I should have it ready to just remove a couple of bolts and heav it out of the frame tomorrow.
Also, this engine is out of a 1980 750E 4 valve. It should be the same engine as Rich's 82 750T shouldn't it?

 

[Nessism]

Also, this engine is out of a 1980 750E 4 valve. It should be the same engine as Rich's 82 750T shouldn't it?

As far as I know it's the same.

Those engines have oiling issues. One of the few GS engine's that are not bulletproof. There is a fix that involves shimming the oil pressure relief valve. Details available in the archives. That said, don't think that's the cause of this engine failure.

 

[Rich82GS750TZ]

Checking parts fiches on partsoutlaw, the crankcase has the same part #. That tells that the frame mount holes are in the same place. That at least ensures me that I shouldn’t have any issues bolting it to the frame, and that I can use my case covers. Norm sent me some pics that show cross head screws on the case covers, I have bolts.

Cylinders are the same, as are base and head gaskets.

There are differences in the valve cover, and gasket, and head and head internals, cam shafts and whatnot. I don’t plan on swapping any internals from my 82 to the 80.

And Norm, you certainly don’t halve to clean on my account. I’m just happy to be getting a replacement engine so quickly and within driving distance.

 

[93Bandit]

So, if all 4 intake rockers broke, how on earth were you able to limp it home??? I would think if the rockers are broke, the intake valves wouldn't open and it wouldn't run?

 

[Rich82GS750TZ]

I didn’t limp it home. I wrote about 1/2 mile. Probably wasn’t quite that far. Didn’t measure it.

 

[zuluwiz]

You should put crime scene tape around that engine. Ok, the valve rockers appear to have stayed in the cam cover, but that adjustment screw went someplace after it ate the chain guide. You will need to find it and examine all the damage it did during it's tour of the engine. Hopefully not too bad. As I said earlier, a total teardown is probably a Good Idea, but it can wait until youve got the new engine installed and running. I think we know what youre going to be doing next winter.

 

[Rich82GS750TZ]

Yeah, that valve adjuster nut must have gone down the cam chain tunnel. I haven’t found it yet. You’re right, put Norm’s engine in so I have a bike to ride. Then totally tear down the original engine his winter.

 

[93Bandit]

I didn’t limp it home. I wrote about 1/2 mile. Probably wasn’t quite that far. Didn’t measure it.

Ah, gotcha. I must have misunderstood.

 

[TeamDar]

When the engine is over-revved the valve train floats. The rocker arms are not following the cam lobes smoothly anymore but are being hammered open and slammed closed. All of this causes wild harmonic vibrations which can loosen the valve adjusters and even cause the screws or nuts to back out. When an adjuster screw separates from the rocker, especially the ones closest to the cam chain tunnel, they frequently get drug down with the timing chain. When the screw gets jammed between the crankshaft sprocket and the chain the sprocket teeth jump the chain links throwing camshaft timing out of synchronization. The results can be bent valves or in this case the valve to piston interference was significant enough to break the rocker arms. I have personally found valve adjuster screws backed out on engines that the owners admitted to missing a gear and severely over-revving the motor. In one instance several screws/nuts had fallen out of the rocker arms. All but one screw was still laying in the head. The last screw was still in the crankshaft sprocket area and had cause the cam timing to jump time. All 8 of the intake valves were bent and required replacement. Dar

 

[GSXR7ED]

This is going to be intersting...an 8V/750E engine (1976-78) into a 1982 16V/750T.

I'm not saying it isn't going to work...I'm just amazed how these bikes can be interchangeable.

Spyder put an 1100E engine into his "T" but it was from the same year...1982.

Watching this thread with interest Rich!

Ed

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[Big T]

TL/DR??

See post #21

 

[GSXR7ED]

I see I researched the earlier year 750...1976-78...thinking it was a "78 model. My apologies.

It's still an 8V engine...16V first came out in 1982 if history serves me right.

Ed

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[Rob S.]

This is going to be intersting...an 8V/750E engine (1976-78) into a 1982 16V/750T.

I'm sorry, I can't condone this.

You broke my heart, (Fredo), when you decided against an 1100 16 valve. But then I thought you were going with a 16 valve 750.

I wish you luck, I'm sure you'll do very well, especially since your interests don't conflict with my interests.

(And yes, the nurse was just here with my 'medicine.' )

 

[Rich82GS750TZ]

You guys are all confused. I just left Norm’s with a 1980 16V 750E engine. The only real difference I see is in the head design. It is a 16v. Promise.

sorry Rob. No 1100 this time.

thank you Norm

 

[rphillips]

Hey Rob, did the nurse take your temp.? Was it the same on both ends? Don't let her use the same thermometer. Oh, sorry, that's too personal. If a 16V 1100 eng. works great in a 8V GS1000, wouldn't an 8V 750 eng. work just as well in a 16V GS750, if that were the case.

 

[TeamDar]

You guys are all confused. I just left Norm’s with a 1980 16V 750E engine. The only real difference I see is in the head design. It is a 16v. Promise.

sorry Rob. No 1100 this time.

thank you Norm

The only difference should be the number of valve cover bolts. Dar

 

[storm 64]

It was nice meeting Rich today, a very nice guy. Well, last night when I was removing the exhaust header pipes, yep you guessed it, three broken exhaust bolts... I got up early this morning, pulled the head. I then took it to the shop to drill out the busted bolts. When Rich got there I had a good jump on the job. I didn't want to keep him any longer than necessary. Then we went back to my house to finish pulling the engine. All in all it went pretty smooth. I hope everything works out for Rich.

 

[GSXR7ED]

You guys are all confused. I just left Norm’s with a 1980 16V 750E engine. The only real difference I see is in the head design. It is a 16v. Promise.

sorry Rob. No 1100 this time.

thank you Norm

Well, I guess that’s putting it nicely...confused...appreciate the lower level degradation. lol (I’m sincere when I say that so please don’t be offended)

Good job, Norm...you going out of your way to clean up prior to Rich’s arrival...and then expediting the bolt issue so as not to keep Rich waiting too long.

Glad it all worked out!

Ed

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[Rich82GS750TZ]

Yep, Norm certainly went above and beyond to help me. He’s the first GSR member I’ve had the pleasure to meet in person. Maybe someday I’ll get to a rally, if I can stop sabotaging my own bike.:miserable:

Thank you again Norm. With a little help from you and the rest of the great folks here, I’ll have my bike up and running before too long. I return to work tomorrow, so it’ll take some time working a little every evening and weekends.

Also want to thank the person ahead of me in the Dunkin’ drive through for paying for my coffee. That was so nice. :applouse: And unexpected.

 

[GSXR7ED]

That’s so cool!

Posting pic of some GSR brethren...meeting for a good cause...helping a member out!

Ed

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