Baby's first leakdown test

I still can't find the source of this idle surge on the '76 GL1000, so I decided to start from scratch.
I ran a leakdown test on all the cylinders at TDC to check for valve issues. I could have pulled the camshafts and performed the test throughout the piston's movement range to see if there's a particular problem spot on the cylinder walls or piston rings but I'll wait on that for now and just run a compression check next.

Since the plugs were out I decided to check them.
They look a little dark so at least it's not a lean condition.
Most importantly they're all the same color.
This is evidence against an intake runner leak on one carb.

Here are the results of the compression test:

Click for full size picture.

Cylinder	InputPSI	LossPSI	LossPSI (2)	%Lost	%Lost(2)
1	90	86	85.5	-4.444444444	5
2	90	86	85	-4.444444444	5.555555556
3	90	86	86	-4.444444444	4.444444444
4	90	88	88	-2.222222222	2.222222222
1	80	75.5	75.5	-5.625	5.625
2	80	75	75	-6.25	6.25
3	80	75.5	76	-5.625	5
4	80	76	76	-5	5
-	-	-	-	-	-
1	70	66	66	-5.714285714	5.714285714
2	70	64	64	-8.571428571	8.571428571
3	70	66	66	-5.714285714	5.714285714
4	70	66	66	-5.714285714	5.714285714
-	-	-	-	-	-
1	60	56	56	-6.666666667	6.666666667
2	60	55	55	-8.333333333	8.333333333
3	60	56	56	-6.666666667	6.666666667
4	60	56	56	-6.666666667	6.666666667
-	-	-	-	-	-
-	-	-	-	-	-
1	90	86	85.5	-4.444444444	5
1	80	75.5	75.5	-5.625	5.625
1	70	66	66	-5.714285714	5.714285714
1	60	56	56	-6.666666667	6.666666667
2	90	86	85	-4.444444444	5.555555556
2	80	75	75	-6.25	6.25
2	70	64	64	-8.571428571	8.571428571
2	60	55	55	-8.333333333	8.333333333
3	90	86	86	-4.444444444	4.444444444
3	80	75.5	76	-5.625	5
3	70	66	66	-5.714285714	5.714285714
3	60	56	56	-6.666666667	6.666666667
4	90	88	88	-2.222222222	2.222222222
4	80	76	76	-5	5
4	70	66	66	-5.714285714	5.714285714
4	60	56	56	-6.666666667	6.666666667

It's important to note I performed this test on a cold motor. It's generally better to warm up the motor first as your numbers will be more accurate. However, there were still no glaringly obvious problems indicated by these results.

I suppose the next move will be to compression check the cylinders and see if they are good in that aspect.

Still no progress - GL1000

So the carburetors are still giving me problems.
After the bike has warmed up the idle will occasionally surge up to 3000 RPMs again and then come back down after a second or two.

I took a video to see if anyone has encountered this before and can help me identify the problem.
Please comment if you have any suggestions.


Note: I did not touch the throttle in this video.

Slide slide slippity-slide

So polishing up the slides that were on the '76 carbs didn't work out so well. I still have surging RPM's off-idle. Frustrated, I said fuck it and scrapped them altogether.

But I do have an ace up my sleeve.

I just pulled these beauties off a (for parts) set of 755A carbs.

See that scallop cut in the bottom of these? Yea that means they're more badass than the flat bottomed girls I yanked out. It also means they'll allow for more airflow, particularly at full throttle.

The best part about these is they're a complete set of matching tops and slides with no damage or scrapes.
They were a bit dirty though.

...and after 5 hours of polishing: (my forearms look like Popeye's)

The needles buffed out nicely.

I really hope these do the trick. I've been on a wild goose chase for about a week now hunting down one problem after another with this bike. This past weekend alone I've had the carbs on and off the bike 5 times.

**Update10/19**

The bike starts and idles fine, but still seems a bit slow to decrease RPM's.

I'm going to set the timing dynamicallty, then try and sync the carbs as best I can and see if that makes a difference. 

I already swapped the #115 slow air jets for #110's. It was quirky at first but eventually I got the idle adjusted and now it idles strong.

Two steps forward, two steps back.

Perhaps I was a bit optomistic about this past weekend. Things didn't work out quite like I planned.
Instead of going to see Deep River on Saturday and take the Fall Foliage ride to Graves Mountain on Sunday, I spent the entirety of my weekend sorting out carb problems.

Friday:

 I installed new spark plugs and plug caps,

and put the rest of the bike back together; radiator, fan etc...

Then finished rebuilding the GL1000's carbs (for the first time).


Saturday:

The carbs were mounted on the bike, primed, and ready.

However, when I tried to start the bike I got a quick "put-put-put," like it was going to fire, and then nothing. I tried again, and the bike SPEWED fuel out the right exhaust all over the garage.
 

Apparently the Clymer's manual was very wrong about the procedure for setting the float height.
The proper way to do it isn't from the gasket surface, or the gasket. Instead, measure the float height from the lip around the edge of the gasket.

So, I removed the carburetors, re-adjusted the floats, remounted them and tried to start the bike.

Before.

The correct orientation for setting float height.

After.

Still no luck. So I ran the handy-dandy troubleshooting checklist: Spark, Fuel, Compression.
Well, cylinders 3&4 had no spark. Luckily it turned out to just be a loose wire.

At this point it was late, and I didn't want to piss off the neighbors by starting the bike
So,I decided to call it a night and try my luck in the morning.

Sunday:
I woke up, threw on some pants and, like a kid on christmas, dashed for the garage.
I hit the starter button and after a minute or so of struggling she fired a little bit.

She was having trouble starting and running so I decided to pull the carbs again to double check everything and bench sync them.

Draining float bowls again.

Double checking float heights.

The floats were all set perfectly, all the passages were clear but got blown out with compressed air anyway.
I syncronised them using a guitar string and threw them back on the bike.

Once mounted, I hit the starter button and she fired right up without hesitation!

But then, I gave it just a touch of throttle and the engine RPM's surged to 3000 and stayed there even after I let off the throttle. After a few more attempts and adjustments I couldn't fix the problem.

When I rebuilt the carbs I swapped out the slow air jets for smaller ones to enrich the idle and off-idle mix
so that the bike wouldn't have a flat spot and stumble when moving from a stop.

Hoping that this was part of my problem I decided to swap the jets out, but I thought,
"I'll be damned if I'm taking those carbs off again."

The slow air jets are pretty hard to access with the carbs still on the bike, but I had just the right tool for the job:

This photo was surprisingly hard to take.

Slow air jet removed...

...from here

Unfortunately this didn't fix the problem, so I guess I'm damned.

The only other thing I could think that might have caused the surging RPM's would perhaps be sticking slides. I pulled the carbs again, hopefully for the final time, and polished the carb slides, tops,
and bores with some 0000 Steel wool.

Only the finest for polishing my carbs!

I think this box is older than I am.

Before. Notice the scuffs.

After polishing.

I also polished the inside of the tops.

I reassembled everything Sunday night and hopefully with some luck we'll find out if this fixed it tomorrow!



...and by request I present to you, friggin' spiders:

I think he was sick of the paparazzi and decided to take his meal elsewhere.

Piecing together a set of GL1000 carbs

I have a feeling this is not going to go as smoothly as planned.

I have 3 sets of Keihin 755A carbs and I'm not sure if I can build one usable set out of all the parts from all three. One set is pretty much completely trashed; busted posts, too corroded to even see any of the jets, let alone remove them, the other set has a busted float pin post on one carb and the emulsion tube is stuck in another. I have yet to crack into the third set but I don't imagine it will be in much better shape.

On the upside I get to take a lot of nasty pictures using my homemade macro lens:

Float seat from the '75 Gl1000  carbs.

Here's a close up of one of the float seats. There's some pretty gross stuff lurking around in those carbs.

I'll get some more pics of the process once I make some progress.

*UPDATE* 9/30
Still on the prowl for some proper Keihin 758A carbs. I've had a few promising leads so if I can manage to pull that off I'll go that route and save the 755A rebuild for when I get the '75 up and running.

One of these things is not like the other one.

One of these things just isn't the same.

Front left carb body

Back left carb body

Back right carb body

Front right carb body

Some words of wisdom from the man himself,

"Unless you know the entire history of a bike, you can't rule out that a previous owner made an ill-advised carb and/or engine swap. Believe me, this happens all the time. 
-Randakk 

Truer words have never been spoken.

According to Randakk's Tech Tip #32, this guy broke 2 of the 3 carb swap rules in one fell swoop.

2. Never mix carbs from late series to an engine in the early series. (the 769A's are from the 1978 GL1000)
3. Never mix carbs within one rack that have different codes.

I think I'll write a letter:

Dear Previous Owner,
Fuck you.

'Ignorance' does not even begin to describe your despicable actions. I hope the future holds for you, a fate worse than death. 

Yours in Christ,
Charles

Resistance is futile ...or too great, either way it won't run.

The GL1000 has a ballast resistor which ensures the ignition coils get the proper voltage at startup and during normal operation. 

When the starter motor is engaged the resistor is bypassed because the starter will draw so much current from the battery, that the coils will naturally get the 7-9v that they need. 

When the bike is running however, the ballast resistor limits the voltage to the coils so that the otherwise 12v it would be getting is limited to the proper7-9v. This keeps the coils from overheating, the points from detonating or burning up, and the condensers from overworking and failing.

As, it turns out that my ballast resistor is shot. It should read exactly 3Ω when tested.

This one looked a little roasted around the base of the terminals and tested at 3.5Ω.

Rather than source another one from NAPA, I just decided to man up and get a Dyna electronic ignition. 

The Dyna-S supplies the appropriate ballast resistor (different Ω). The only downside to using the included one is that it doesn't fit the stock bracket. This is not a problem if you have a Dremel and file handy. Just shave down the edges on the terminal side of the ballast resistor and the bracket will slide right over.

The only downside to installing this new Dyna-S is that it completely negates all the work I put into getting the stock points set and condensers properly grounded, since all that gets removed.

That's it! You're grounded!

Still trying to sort out the GL1000's problems, I decided to take a break from the head scratching and do something productive.

The condensers are normally grounded to the battery box. This is a poor place to ground them because of their distance from the breaker points plate, especially when you consider how prone that battery area is to rusting due to gasses vented by the battery. The Ideal place to mount them would be on the points plate itself but there's no room in there so we must improvise a better solution.

So I busted out some spare 8 AWG wire, some shrink wrap, and a couple of ring terminals and got to work.

The result:

Wire attached to the condenser ground.
Notice the rust on the battery basket where it's mounted.

Wire barely peeking out from behind engine mount where it's grounded.

Altogether pretty clean install.

I figured it would still be good practice to properly ground the condensers, despite the fact that I plan on running a Dyna-S in the near future. Who knows, maybe my electronic ignition could fail and I would have to throw my spare points plate on in order to make it home. It would be a shame to burn through a set of points just for that.

Symptoms of poorly grounded condensers include:

• Exploded, prematurely worn, or damaged points
• Poor idle
• Hard starting
• High rev missfire

I SUCK at painting... seriously

So I painted Joe's K3 and my Gl1000 tank.
That was way harder than I expected it to be.

The tank came out fairly nice because it was mostly flat surfaces and easy to reach spots.

Unfortunately, Joe's frame had more nooks and crannies than an English Muffin. There are also some really tight spaces to try and fit the HVLP gun through in order to spray. The combination of these factors made it really difficult to paint.

I managed to get the primer down without a problem but had a really hard time with the ceramic frame paint.
I also didn't buy enough to practice a whole lot (the tank was my practice).

Next time I'll definitely overbuy on paints for practice and might even get a smaller detail gun to make it easier to paint the frame.

Stripping

Stripped