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Old 10-06-2008, 02:04 PM   #181
Stagehand
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well-

dry soot= fuel rich, while wet soot= oil rich.

I guess you'd have to figure out where you spent most of your throttle time to determine in what range it was rich or lean. And is it possible to hook up a manometer to slide carbs? Not to say anything against your ears, but my ears are like a bad pair of blown speakers.

Makes sense that it ran ok with the needle lowered and the throttle wide open- you are almost skipping the needle jet and are onto the main.

Hmm.. 80-90 deg hotter... I'm befuddled.

How about valves? maybe a tighter exhaust valve would be in contact with the head longer and heat up more? <-- long shot
or rockers... meaning maybe its friction heat buildup? <--even longer shot
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Old 10-06-2008, 04:31 PM   #182
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Quote:
Originally Posted by Stagehand
well-

snip

Hmm.. 80-90 deg hotter... I'm befuddled.

How about valves? maybe a tighter exhaust valve would be in contact with the head longer and heat up more? <-- long shot
or rockers... meaning maybe its friction heat buildup? <--even longer shot
Got the soot thing pretty well worked out: that was definitely dry "too rich" soot, which I got cleared out by compressed air, reseating jets, and just a general going-through.

And yes, the needle jet and needle LOOK fine, but I think I will replace them.... I suspect that the needle jet gets opened up over time. cheap and easy enough to do.




I'm gonna keep looking at the hotter-on-one-side issue.... maybe as I get my carb issues sorted out, it will go away quietly..................

I must say that this infrared thermometer is not something that I have played with, much, so as I develop a more "statistically significant" database, I will perhaps also develop some smartnesssss........



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Old 10-06-2008, 05:22 PM   #183
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Quote:
I'm gonna keep looking at the hotter-on-one-side issue.... maybe as I get my carb issues sorted out, it will go away quietly..................
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Old 10-06-2008, 07:22 PM   #184
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I feel like I am living with an echo echo.....

Have been posting/reading about carb issues on another thread, which is worth reading in its own parallel universe:

Airhead Carb Issues deals with the Bing Type 53 carbs on the 60/6 and /7, same as my bike....

worth looking at, for varying posts and whatnots.....
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Old 10-06-2008, 08:07 PM   #185
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The other guy's mention of air restriction in that thread reminded me I had thought about maybe one of your tailpipes was somehow different from the other, producing different temps. Maybe rusty inside... something like that. Seems like you controlled for air In, so maybe air Out was different.
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Old 10-06-2008, 08:26 PM   #186
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Maybe, or...

Quote:
Originally Posted by Stagehand
The other guy's mention of air restriction in that thread reminded me I had thought about maybe one of your tailpipes was somehow different from the other, producing different temps. Maybe rusty inside... something like that. Seems like you controlled for air In, so maybe air Out was different.
When I changed pipes I had a whole lot of carbon on the right side (had to bang the pipe out with a rubber mallet, then a wood block and a sledge). Had to ream it out with some fine grit, and fired it up to clear any blowback before I put the new pipes on.

Now here's the weird part (exept for the bloop bloop bloop aquarium car noise it made - way cool, like a sound effect from Spongebob) The right cylinder is noticeably cooler, and also blowing out less pressure, than the left side. No restriction to speak of here, as the cylnders were wide open, blooping away. My wife thought it was a bubble car.

Temperature difference is confirmed by bluing of the new pipes; it was almost immediate on the left side, still just a bit yellowed on the right 2000 miles later. Don't have a gun to shoot it wth, but it was noticable just listening, looking, and putting my hand over it when the pipes were off.

Runs great, pulls strong, compression test was ok on both sides, so I'm a little lost as to why the difference. Valves adjusted, timing good, carbs balanced. No real evidence of rich or lean running on the plugs when I changed them, they were a nice tan, of indeterminate age - though I'm gonna pull them again tomorrow because I'm curious now. I'm getting mid 40s for mileage. All of this is approximate of course, as I am no expert and most of this stuff was done by me.

With the carbon, I'm guessing either rich on that side, or maybe rings going? But that's a total guess.
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Old 10-06-2008, 09:03 PM   #187
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If the plugs look good, then the carbs are most likely fine. That also vindicates the rings, piston, and valves. The only thing left is the ignition timing or, possibly, greater back pressure in the muffler.

Are both cylinders firing at the same time?

Did a mouse set up residence in your muffler?
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Old 10-07-2008, 08:12 AM   #188
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Thanks again to all for your thoughts...

I do feel like I am getting the carb puzzlements down to a minimum. But the head temps...

Mine is a 2-into-1, I have had it off various times for painting, whatever. The two header pipes are very short, and go directly into the muffler inlet. I Have never felt that one or the other pipes were "heavier" or "dead" sounding when holding them.... you know, how a brand-new clean pipe feels vs. a pipe with some crusty buildup.....

My pipes are black, so no bluing or golding to notice.

But, easy enough to pull them off and inspect thoroughly. Otherwise, it will just become one of those mysteries of the universe, like how the hot water is always on the left......
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Old 10-07-2008, 08:53 AM   #189
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Quote:
Originally Posted by bpeckm
Otherwise, it will just become one of those mysteries of the universe, like how the hot water is always on the left......
Thats not a mystery- thats one of the three golden rules of plumbing, along with "shit flows downhill" and "payday's on Friday"
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Old 10-07-2008, 11:30 AM   #190
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......Don't forget the fourth: never lick your fingers
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Old 10-07-2008, 02:27 PM   #191
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Quote:
Originally Posted by bpeckm
......Don't forget the fourth: never lick your fingers
Yuck. Just yuck.

Of course, that rule applies for welders and electircians, too

Bike looks really nice, btw.
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Old 10-16-2008, 06:58 PM   #192
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One side is definitely running rich.... suspect float level.

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Old 10-16-2008, 11:48 PM   #193
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I thought I was too old to fall in love again.

Wonderful reporting, great images, professional and deliberate work!!!!

Started at first post and read straight through to 192, and was sad that I'd read the whole story to-date.

Brought Bill Flemming of C&D BMW of Freeport, IL, to mind. He's gone now, but he was my equivalent of your expert. Not only knew everything, but WANTED to help you know.

Gotta say, though, although you mention times of impatience, I can only imagine how anxious your son is for you to get ON WITH IT. Young, male, and gonna have a custom bike...I remember (barely) those days.

Congratulations on a great job so far, and great story-telling.
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Old 10-17-2008, 01:17 PM   #194
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I'm enjoying a great deal this rebuild report. It's been a long time since I rebuilt my '76 RD400 (since sold) but it is fun stuff.
I'll go back to lurking, but wanted to pass along a quick story about a 600/6 my boss owned. My boss in 1971, that is.
He was a retired Boeing flight engineer, a tough little bird by the name of Reub Weltha, a Norwegian. He opened a bike shop in KC, where I lived, and gave me a job because I was from Wichita, where he still lived. He chuffed back and forth on the 600 from his basement apt., near the KC shop, to his wife, hearth, and home in Wichita, every weekend. 400 miles every weekend. He carried home a big leather carpet bagger's case with his dirty clothes, tied to the back of the seat.
He loved tinkering with the 600. One morning, I got to work early and there was Reub, 7 a.m. on a Saturday, tinkering with the 600. He proudly told me he had worked the valve clearances and timing to achieve an idle of 200 rpm. He fired it up, and sure enough the 600 ran smoothly. puff.....puff.....puff.....puff.....puff, the whole bike sort of rocking mildly back and forth. He said, "Those Germans still know how to make a good engine."
I miss old Reub. Sorry for the hijack, but this bike is exactly like Reub's.
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Old 10-17-2008, 08:10 PM   #195
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Kismet, thank you for the kind comments. I have enjoyed this project, immensely, and it always fun to figure out the problems that we all have on these bikes.

Bake: LOVE that story.... though Reub Weltha had a LOT more patience than I in fooling with the idle.... I've got my 50/2 so that it will pop pop pop at idle, but I attribute it to the heavy flywheel and mild compression. My 60/6 is not so pliable at idle, at least not that I have learned, yet.

But both engines just love to howl at 4500-5500 rpms... and that sound just digs down into your soul so much that you just HAVE TO get out and wind 'em out now and again....

Again, thanks for the posts.. and glad that my little project has hit a sweet spot somewhere, somehow...
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