Jdub goes there 1981 650e rebuild

[jdub6092]

https://www.facebook.com/share/v/14Z6fMgwuf/?mibextid=qi2Omg

I'm not an active facebook user, but wanted to share a video to see if anyone can recognize this sound.

[jdub6092]

I haven't put the rubber dampers on the engine. Wondering if that might help.

[melchiro]

I clicked your Facebook link. It didn't go anywhere. It says, " This content isn't available right now".

I am a Facebook user.

[Rich82GS750TZ]

Took me to a clip from the old Carol Burnett Show. Harvey Korman and Tim Conway were so funny together.

[jdub6092]

I clicked your Facebook link. It didn't go anywhere. It says, " This content isn't available right now".

I am a Facebook user.

Sorry, I forgot to make it public. Should work now.

[Big Block]

Yikes, that sounds terrible. I hope all the valves didn't kiss all the pistons.

[jdub6092]

I think for sure it is something to do with the cams. I can now hear a slower click-click while it's cranking.

[jdub6092]

Turns out that the cam chain goes from extremely taught to jumping a tooth or just loose. That's the click sound. I measured the links and it is well within specs. That had to be an incredible amount of force on the chain at higher revs.

It didn't do this when I rotated manually many times.
I deployed the tensioner and it did what it should. Backed the screw off 3/8 of a turn and tightened the lock nut.

Ed, I think you called it.
I do recall the guide was kind of sticky as well, but when it was closer to the head wall.

[jdub6092]

I untightened the tensioner lock nut and the slack went away.
I can see that the shaft screw tightened right along with the nut. DOH! Should have been intuitive.
Timing is still good, so no tooth jumping ocurred.
Very little room to work, so will need to dance with screw and nut, until the correct screw backoff is reached.
Maybe this should go on the list of newbie mistakes.

Since I had the cams exposed again, I decided to check shim spacing again. All still in spec, but a few got tighter.

[Nessism]

In case you didn't realize...
Routine goes...loosen the nut on the setscrew, wind the tensioner up as the pushrod is pushed inside the body. Tighten the setscrew, to hold the plunger inside. Install the tensioner onto the cylinder. After the cams are installed, and everything timed correctly, before rotating the engine, loosen the setscrew, allowing the tensioner pushrod to shoot out, removing slack in the cam chain. Back off the setscrew a full turn or so, then set the lock nut again.

[jdub6092]

In case you didn't realize...
Routine goes...loosen the nut on the setscrew, wind the tensioner up as the pushrod is pushed inside the body. Tighten the setscrew, to hold the plunger inside. Install the tensioner onto the cylinder. After the cams are installed, and everything timed correctly, before rotating the engine, loosen the setscrew, allowing the tensioner pushrod to shoot out, removing slack in the cam chain. Back off the setscrew a full turn or so, then set the lock nut again.

Thankfully didn't have to remove it.
One note to add: After backing off the setscrew, hold it in place while tightenening the lock nut.

[jdub6092]

What do you think?

https://www.facebook.com/share/v/15nnAmLcQb/?mibextid=oFDknk

[Nessism]

What do you think?

https://www.facebook.com/share/v/15n...ibextid=oFDknk

It sounds amazing. Good job!

[Griffin]

What do you think?

https://www.facebook.com/share/v/15n...ibextid=oFDknk

That sounds great. The 550 and 650 are the quietest GS engines when finely tuned.

My 650E engine is super quit. It literally sounds like a sewing machine at idle. Had an ‘80 550L that was really quiet too.

[jdub6092]

After a few more newbie blunders I won't even mention, I got the rest of the parts installed and torqued everything down. The Mighty MAX YB14L-A2 battery seems too tall and wide as I can't fit the side cover over it.
It's hard to start when cold, and the choke really only had an effect the first time. The 1-1/2 year old battery also won't hold a charge and doesn't give many cranks before it bogs down.
The exhaust smelled terrible (clearly rich) so I backed the mixture screws from 2 to 1.5 turns and it got much better. I don't have the tools to sync the carbs so I will likely take it to a shop to have it dialed in.
Anyway, I tooknit out for a 10 minute drive around the neighborhood. Kept it under 40mph and 3500 RPM.
It responded well, but not great. When I was finished there was some light almost clear smoke coming from the engine for about 5 minutes. It was pretty hot.
20250110_163715.jpg

I've been putting off painting of the fender and fairings until I know what I have mechanically.