OK, some updates.
Long post warning again!

First of all my homework: I remembered to verify these again with the bike running 2M.
Blocking the pilot ports at idle will stall the bike.
Blocking the pilot ports at 3000-3500 rpm’s causes dramatic rpm drop.
Blocking the main port has no effect as that circuit only comes into play at full throttle.

I figure this proves the pilot circuit is clear and operating properly.

On proboards.com com 5twins said re: Advance rod;
“It wasn't easy to measure, but near as I could tell, I had about .015" end play. I shimmed it down to about .005". You can't go too tight or the advance rod won't advance - it will bind up when you tighten the disc down. Check it by rotating it by hand."

I checked mine and I have a good 0.5mm or better than .020” end play. Gonna need a bunch of shims.

When I started the bike this time it wasn't running on the left side. Huh. Pulled the plug wire and it started firing if I rested the cap on the plug, Was this in essence increasing the gap? Switched the plugs side to side, problem followed.

Plugs looked glossy wet, not sooty. Thought maybe they were still rich. Put in a new plug, all good. This has happened to me before, and I thought it was from rich carbs. Didn't know enough then to understand what this might mean.

Used Paul Sutton's piece of cardboard throttle stop screw shim idea to hold the rpm’s @ 3000 - 3500.

Wanted to check the timing before doing anything else.
My timing on both cylinders at idle is jumping around a lot worse than seen in 2M’s video.

Right side: Will sit on the full advance line then will advance about 3°, then will drop 4° - 5° and “bounces” around back up to the line. This continues to happen back and forth. I would say the total range of movement back and forth across the full advance mark is about 8°, maybe a little more.

Left side: Sits on the full advance line with some definite “bounce” past the full advance line.

So at this point I think I'm done.


Not done as in throwing in the towel, but done with this stock ignition. Looks like an upgrade is imminent.

Just had to test carbs again to rule them out. Figured it would only take a couple minutes to swap them to my other bike, the 78 Black. 4:11.6 actually. Idled really smooth, so I knew carbs had to be good, and my timing and other problems on the 77 Blue are ignition related.
Mix screws now set right 1 ¾, left 1 ¼. And that was done in a few seconds. I’m sure I can get them closer.

After Black Betty (the 78), warmed up it started backfiring through the exhaust on the right side, so I suspected an exhaust leak.
I guess this is a pretty good tell on that.

78E Exhaust Leak.jpg


Even with that leak, it still idled well, and pressure on the pipes felt good so sync is close. A little hard to tell with that backfire but close.
Rule out carbs (I hope)

But…....................man I hate that word these days.
Looks like I'm receiving a baptism by fire on this old girl. I’m getting beaten ‘Black’ and ‘Blue’.

When I had the Blue revved up and holding at 3000 - 3500 to check full advance timing, I saw a lot of smoke from the exhaust. Hadn’t noticed a lot of this before and when I did I passed it off to burning off carbon on the pistons then to rich carbs.
Thought maybe still rich, but looked more white/gray than black. So I put the carbs back on Ol’ Blue to see if that little smoke problem might have just cleared itself up……...lol.

Once it warmed up, at 3000-3500 rpm it would blow white/gray smoke, more on the left side than the right. I knew this wasn’t a good sign and probably meant bad rings, valves, seals?

Checked oil level, definitely down, so it’s been burning oil since the last oil change 04/23/17.
No fuel smell in the oil though.
Mileage 33844 Kms, 21029 miles.

These look oil fouled to me.

plugs.jpg


Checked compression when warm:
Left 155 / 160 /160
Right 150 / 150 / 150
So I guess my rings are OK?

Was going to build a leak down tester out of some odds and sods but haven't been able to find a Schrader/check valve yet. Figured after reading some comments by gggGary, seeing if and where it is leaking air is more important than how much pressure it's losing.
So I just used this in the plug holes, cylinders TDC, carbs off, exhaust still on.

IMG_20170721_165919.jpg


Air leaks out both carb manifolds and with my hand blocking the carb manifold inlet, can hear it out each muffler.
Looked at intake valves, they look pretty carboned up I think.
Right
77D Right Valve.jpg


Left
77D Left Valve.jpg


Haven't pulled the exhausts yet to inspect exhaust valves. Guess I should do that as both sides are leaking out of mufflers as well. Looks like the biggest challenge doing that is separating the cross over pipe. I like Fred's idea of pushing it apart with a bolt/all thread rig. Any other tips on removing the exhausts?

I have read gggGary’s meatball mechanic valve carbon clean up thread and I have looked at Farrell's instructions on changing valve seals while the engine is in the bike.

Other than visual inspection, is there a way I can tell if it’s carbon build up versus bad valve seals?
Any other tests I should be doing?

Hoping to avoid pulling the engine and doing the top end, should I:
  1. Try gggGary’s meatball mechanic carbon clean up fix, then test?

  2. If no joy, replace valve seals with engine in bike, then test? (Although I see this isn't an easy thing to do even for an experienced mechanic.)

  3. If all good, then install new Pamco / E-advance?
  4. Or, please say it ain’t so. Pull the engine, lap valves, new seals, new cam chain and guide, and whatever else I should do while I’m in there. Would head have to be machined?
Guess I’ll save all the questions for door #4 until you guys say that’s the route I need to take.
Not too excited about this idea. The last motor I tore down and rebuilt was a lawnmower motor in High School Auto Shop class and I’m not sure it ever ran again. Not a good track record.

Boy, I don’t know which will be smokin’ worse, my bike or my credit card.

I was sitting a spell thinking maybe I should have just left this bike in storage.
But, then I wouldn’t have met all you guys, and would have missed out on all this fun.
I thought I’d be wrapping this thread up soon but it looks like it might go on for another page or two.
You guys are sure going to get sick and tired of me…..lol.

I'm sitting down, holding my breath, looking at engine stand plans, waiting for feedback. Thanks again guys.
 
Robin, these old bikes are taking you to school aren't they? I wish I had more experience with rebuilding engines and had good advice to offer, but like you, I'm a pretty good parts changer and tuner upper, but haven't been inside motors much. So I will be watching and cheering from the sidelines and hopefully learn something from your journey. Good luck my friend.
Bob
 
LOL, thanks Bob, but hey, just do your valves already eh, ya know you want to, take lots of pics. You always go first buddy. ;)
 
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Sorry, Rob, but I guess you would prefer the hard truth.

Smoking exhaust, not good.
Black oil-fouled plugs, not good.
Black wet backsides of intake valves, bad seals.
Oil intrusion into combustion chamber, that stuff burns too, but differently, and screws up tuning efforts.

A bike like that, coming into our shop, would strongly urge a top-end overhaul.

A few experts here might could get away with various little tricks, but that's not the route for apprentice mechanics. There is a strong likelyhood that there's other things in there needing attention, and those experts might could detect those, in their mysterious ways, not easily documented.

Expect the unexpected.

You're not alone.
Have a look at Gordon' adventure:

http://www.xs650.com/threads/help-i-broke-it-wont-start-warning-long.40457/
 
Ya, that's what I feared 2M. Thanks for giving it to me straight.

If there's a way to be happy about bad news I guess I just found it.

9/10 years ago I was having trouble with the left plug fouling and shutting down. Thought it was a sooty rich plug so pulled the carbs and cleaned them all out. Bike ran great for a few days then left side shut down again. Cleaned the carbs again, problem kept repeating. Finally caved and took it to a local “Big Box Ultimate Toy Store” to have a professional mechanic get it sorted.

New I was in trouble when the mechanic assigned to the job said,”Wow, that bikes older than me”.
He said I was real close and all was good now. OK.

A few days later, same drill, so back to the shop and asked for a mechanic who knew what a Carburetor was. Got the senior mechanic, explained the issue, “Ya, no problem, done tons of these”

Went to pick the bike up and was presented with a bill. Asked why I was being charged again when they didn't fix it the first time. Was told they did a whole bunch of different stuff this time. Even I knew there was only so much you could do to a carb but the manager held my bike for ransom. Paid the bill in protest, never been back, never will be.

A few days later, same problem. Finally gave up, didn't have the time so mothballed it out of frustration.

I now know what an oil fouled plug looks like. Ya think a 'Senior’ mechanic would have too.

So, I am happy, that at least 10 years later, I finally I know what the real problem was and is.

I guess this helps to explain why I was having such tuning problems.
Will spend some time reading through Gordon's adventures.

I have often seen comments on here like, "doing the top ends easy, no big deal". Of course that comment is given by those who have been there many times before. I'm not afraid to research, study and give it a go, but is this a relatively straightforward job if done carefully and methodically or one best left to an expert?
 
Yup - my money is on Robin.

Gimme a call when you are ready and I'll come up the 401 and help you take the engine out of the bike Robin.

Pete
 
OK, thanks for the vote of confidence 2M. Looks like I'm about to learn a whole bunch more, which is a good thing.
Better renew my eyeball pills script. Maybe you guys should stock up too......lol.

Thanks Pete, that's really good of you. Would finally give us a chance to meet in person. I have a buddy here who likes to hang out and is always willing to help out too. Was hoping to wrap mine up so I can help him get his barn find Special on the road. Guess that'll be waiting awhile longer.
We'll see how things develop and I'll let you know.

Back to Gordon's thread and looking at more engine stand plans. Still haven't picked up a welder, always wanted one, gonna do some searching on Kijiji. Or, maybe I'll just adapt a plan to bolt together for now.
 
Well Robin, so it begins. I think probably sooner than later, if we keep these bikes and actually ride them , we will all be faced with your dilemma. I know I've thought many times about the prospect of an engine rebuild or even just the top end. I know it'll happen eventually. You are methodical and enjoy puzzles, I look forward to following your progress and learning something new. Just think how helpful you will be to your friend in the future Miyagi San!
IMG_5151.JPG
 
Thanks Bob. I always said to my boys "the day you stop learning is the day you start dying". I do enjoy challenges and there is no shortage of info on here about doing top end jobs. Plus lot's of expert help only a question away.

Time to start the research phase, get familiar and comfortable with the process, and put together a parts and specialty tool list. Hoping there are lot's of OEM parts still available. Nervously looking forward to it actually. Will feel better when the engine is in a stand, and a socket goes on the head bolts.
 
rob inc. are you an LLC? LOL.
if you have a "little" time I have been toying with doing valve seals on the survivor.It seldom smoke was just noticeable on decel, but riding behind it down a steep hill it was pretty bad. SO I'm right up there on intake seals are bad. Thought it would be a "fun" procedure" and would like to see if some "garyizing" could smooth it out, speed it up. Want to start a seal repair thread?
Comment; I think valve seals on a "sitter" may self heal "somewhat" if they aren't cracked just by running it for a while. I had one motor that needed BP6ES plugs for a while (hotter) so it wouldn't oil foul, then was fine back on BP7ES after a week or 3 of riding it.
 
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LOL gggGary. I'm sure game. Got a lot of reading to do first to get up to speed on this. Unfortunately don't have a lot of spare time right now so I expect I'd be lagging behind, dragging my heels. Happy to contribute any way I can though, and would sure be cheating by watching your progress. LOL.

Was thinking I'd do the starter gear clip fix once the oil is drained before pulling the engine, but could just as easily do it on the bench if it doesn't matter one way or the other. Just thought if I did it while still on the bike I could do a quick test to make sure it was tensioned right and there would still be enough oil in there to prevent any damage.

Keep me posted on your thoughts and let's see what happens.
Thank you.
 
robinc..........................there are tools that are a "must have" and tools that you may "want to" have, for a top end re-build.
You do not need an engine stand. All you need is a clear bench area to sit the engine. Once the sump plate is removed, that flat area sits perfectly on a 2 X 4 piece of wood. Its also very easy to roll the engine forward and stand it on its nose, which is the best position when re-installing the cylinders/pistons. I can't understand why everyone thinks they need an engine stand:banghead:

Here are a couple of pics, when I was working on my engine:
Cyl  Piston install mod1.JPG Engine on bench 1.jpg
 
Don't forget the no-clutch-removal hairpin squeeze Gary!

....although that may simply be impossible.

ALSO: does anyone know if it is possible to replace the top-end oil supply pipe with the engine in the frame?

I was poking around under Lucille's tank and noticed that the pipe is pretty corroded. I've got a pipe, new banjo bolts and lots of crush washers - don't want to start unless I can do it in the frame.

Pete
 
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Thanks gggGary. Hotter plugs are worth a shot, but with my erratic timing issues I'm afraid of running it too much before installing a Pamco and E-advance.

Unless this oil leak is a big contributing factor to my crazy timing in which case, hotter plugs might just clear that up as well.

Will watch with interest and would be honoured to 'work alongside a master' on something like this.
 
That's great news rg, thank you. 2x4's and benches I got. Can take the money for a welder and put it towards chain breaker, parts, etc.

Lots of reading to do and better get Han's book off the shelf.
 
No electronics expert but think someone mentioned a "thin false" signal that may have been a result of a shorted or fouled plug....
any oil pipe messing you HAVE to have a pair of wrenches to loosen/tighten the bottom jamb nut. it's really tight in there you may have to chop up a wrench to get them both in. it's too easy to loosen strip the adapter that is threaded into the case.
 
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