Jdub goes there 1981 650e rebuild

[jdub6092]

More delays and learning experiences.
Was able to get the cylinder installed on the pistons after trying several methods, forgetting to install the dowels, trashing a base gasket and lots of choice language.

Eventually, I found that it was actually a lot easier to use the DIY piston holder blocks and compress the rings by hand enough to insert them into the cylinder walls. The tapered entry really helps with this.

20240810_083027.jpg

[jdub6092]

Got the valves installed in the head and had some difficulty installing the buckets over the springs. Again learning that patience is the key, found that rocking them back and forth while very slowly pushing down at first is the key. Once they are squared up, they slide down easily with assistance from assembly oil.


20240810_083147.jpg

[jdub6092]

Next step was to measure the cam lobe heights. All of them are below service limits by 0.2 - 0.4 mm/.01"-.02" Is this a deal breaker for continuing or would I just expect less than optimal performance?
I've found a used set of camshafts that reportedly came off a bike with < 13k and waiting for measurements. If that doesn't work out, I see that I can still purchase new ones, albeit adding to my already blown up budget.

[jdub6092]

When waiting for parts or other engine building delays, I'm trying to keep busy polishing parts, touching up emblems, etc.
Not sure I like the chromish appearance of the case covers. Any tips for making them look more stock in appearance? 20240810_083304.jpg

[Nessism]

As long as the journal diameter is in spec, and the lobs don't look all scored up, I'd run the cams you have. A tiny bit less lift won't even be noticeable.

[rphillips]

This cam thing got me wondering, so looked it up. It says the hardened surface of the cam should be min. of 2.54mm. So, like he ^^^^ said, your 0.4mm should be of no concern.

[jdub6092]

Trying to get Cams installed.
I noticed that the initial positions with arrows aligned per manual do not allow the journals to seat. There is a cam lobe that is just contacting a shim enough to raise the journal from the bearing surface. Appears to be the case on both cams. Is this normal?

[rphillips]

There won't be a place where a lobe is not on a bucket or rocker, depending on the bike. Check the manual, you check half the valves with cams in one position and the other half with cams in opposite position. If there was a place where no lobe was contacting, you'd set the cams at that point and check all at the valves without needing moving the cams.

[jdub6092]

Thanks rphillips. I cranked down the holders at the synced position.
Now I'm counting cam chain links and my manual says 19 link pins between the vertical arrows on the sprockets (link pin 1 lines up on the exhaust side and link pin 19 on the intake so actually only 18 links between as I read it).
Well, this causes the intake arrow to rotate toward the exhaust side and I have not replaced the cam chain. If I adjust by one link (1-20), both arrows are vertical and the chain is quite taut.

I've watched a few GS550 videos and see that they indeed use 1-20 links. From what I understand, the GS650E is just a bored out version of the 550, so is it possible that the manual is not very precise and possibly means 19 links between alignment arrows?

[jdub6092]

I think I answered my own question. The manual is not correct as it is listed as links 1-20 on the GS650G manual as well as several other models.
The manual also doesn't seem to match the timing marks. It shows text that doesn't match the timing plate and then shows two different sides of the T to line up.

I'll just ask if this is the correct alignment of the timing mark for TDC?

20240817_073317.jpg

[jdub6092]

Went with the above. Doesn't matter. Can't turn the crank with camshaft holders torqued down. It rotates when the holders are backed off a couple of turns.
I knew there would be days like this.

[rphillips]

How tight is the cam chain? you did loosen it didn't you? thinking that may make a difference

[jdub6092]

I followed the manual except i counted out 20 link pins instead of 19. Bolted the holders down evenly, exhaust side first. Then intake cam allowing some slack. Then I installed the tensioner.
Rotated the crank one turn until slack between cams was removed, but it isn't overly tight.
Then I torqued down the camshaft holders and couldn't turn the crank anymore. I lubed the journals and bearings generously.

20240817_200004.jpg

[jdub6092]

I pulled out the valves and wanted to see how the camshafts turned without resistance.
Well, turns out that the journals on both are binding. I cant budge them when the holders are snuggled down. 1/4 turn back on holder bolts and they do rotate, but the exhaust side is still a little sticky.
Could bead blasting have contributed to this?

[jdub6092]

I now think I know why I have binding on the camshafts.
The machine guy I had repair the damaged valve cover bolt threads, said he decked the top of the head also because of scratches resulting from attempts to remove the broken bolts.
I cleaned up the journal bearings and cap surfaces with wd40 and 5000 grit sandpaper. I can finger tight the bolts and the camshafts still move with a small amount of resistance. As soon as I tighten them up further, the camshaft wont budge.
So close to the finish line.

20240823_200258.jpg