Service-New to Me-'81 R100/t

[brittrunyon]

I know how you guys like pictures



So here's the skinny.
1981 R100/t was bought (not by me) in Germany and then sometime later shipped to the USA.
This bike has had 2 owners in it's 32 years of existence.
The original owner sold it 2 years ago after it sat for awhile.
............from 2001 to 2013 only 3,500 miles were clocked (so it didn't actually sit the entire time)
............the 2nd owner had it for 2 years and clocked maybe 1,500 miles of those miles.

Here's what I know:
1. Mileage is 143,000 miles
2. Oct. 1991, 63,000 miles, front wheel replaced due to recall (not rear wheel).
3. Aug. 1995, 98,000 miles, new rings and valves.
4. June 1997, 111,000 miles, new cylinders, pistons and rings.
5. Oct. 2001, 139,000 miles, new valves, valve guides

Here's what I have for 32 years of records........
The original book with 4 years of maintenance.........



Then the original owners records up until 2001 & then just stop.
.............It appears that the original owner was very good with maintenance, oils, bearings, lubes, etc.
.............There is nothing known from 2001 to present time.
.............There is nothing in the records of any other parts being replaced, other than the ones listed above.
.............Could this be true?



There is no records from 2001 to the present.
The 2nd owner stated that he changed all the fluids prior to my taking possession of the bike.
Rumor from the 2nd owner is that the carbs were rebuilt at 70,000 miles (by original owner).

The bike as I see it:
1. There are no oil leaks.
2. It is all "original (?)" OEM parts.
3. Needs a rear tire.
4. The inside of the tank looks great.
5. The starter looks original, could this be true?
6. Plug wires & coils look original, could this be true?
7. There's a slight "clunck" in the head light area when hitting a bump at speed (the steering head bearing test OK).
8. Needs rear brake shoes.
9. Front brakes OK.

What I've done so far (all in this order):
1. Disassemble and clean ignition trigger unit (bean can)-(the idle was sticking at 2,500rpm's)
2. Adjusted valves (.004 In & .008 Ex)
3. Set the timing (more on this in a minute)
4. Syn the carbs with shortening method.
5. Cleaned & lubed all electrical connections. (this helped performance a lot)
6. Removed Pulse Air System.
7. Rode it 350 miles with Seafoam additive in fuel.
8. Replaced throttle cables (they needed replacing).
9. New air filter.
10. New inline fuel filters.
11. 2 new sections of fuel line.

What I'm feeling in the seat of my pants:
1. The power is not what it should be.
2. I wonder about the condition of the carbs.
3. I wonder if the plug wires, coils, etc are not functioning as they should be.

So now what?
First I intend to revisit the timing.
There's sometimes a "stubble" on light acceleration at 1,200-1,500 rpm's.
The Original Manual states:
..........."ignition timing: 6 degrees before TDC = "S" mark on flywheel".
When I did the timing the "S" mark was below the center line but I could not advance because the bean can was at max counter clockwise rotation, as seen in image below.

(sorry, piss poor photo)


Any ideas on this timing problem?

So Now........................

[SOLO LOBO]

Stretched timing chain?

[Airhead Wrangler]

Originally Posted by SOLO LOBO

Stretched timing chain?

Or timing chain installed one tooth out maybe?

[Kt-88]

Originally Posted by SOLO LOBO

Stretched timing chain?

That's what I was thinking.

[supershaft]

Part of the trouble could be the bean can itself. Time to the F mark and see were it goes at idle. They very often do not time both marks at the same time. If that's the case, bend the advance weight tabs so that it will. Very easy to do through the can's inspection port. It doesn't take very much.

[halflive]

Your front fender looks awkward, is it mounted the wrong way round?

[Bill Harris]

What does the F or Z ignition timing mark do at >3000 rpm with the current setting ? It should be centered in the window at that RPM. THAT is the important timing setting, not the Idle "S" setting.

--Bill

[supershaft]

They both are important if you want it to run right.

[Plaka]

Originally Posted by Bill Harris

What does the F or Z ignition timing mark do at >3000 rpm with the current setting ? It should be centered in the window at that RPM. THAT is the important timing setting, not the Idle "S" setting.

--Bill

If the advance system is working, the two should be completely related. if the timing chain is worn it's anybodies guess. If it rides good and don't rattle bad, ride it.

[brittrunyon]

Originally Posted by halflive

Your front fender looks awkward, is it mounted the wrong way round?

Wow.......
Your right it looks backwards, especially with that silly mud flap

More on the timing a little later...............

[Plaka]

Originally Posted by brittrunyon

Wow.......
/snip... that silly mud flap

More on the timing a little later...............

Ever wonder why your crossover looks like crap?

[brittrunyon]

After revisiting the timing.....
...........there is no F mark
..........not ready to bend any tabs in the bean can just yet

At 1000 rpm's the OT & S marks are below the window
.................(the OT mark is above the S mark on the same tab, on the fly wheel)
.................the OT mark can be seen at the bottom of the window but the S mark is out of sight
.................the bean can is advanced (counter clockwise) as far as possible

At 3000rpm's there is "nothing" showing steady in the window

There's no Z mark showing anywhere between 1000 to 4000 rpms.

It rides just OK, doesn't rattle, but as I stated earlier it's a gutless beast which I attribute to old electronics.......maybe?

[Plaka]

Originally Posted by brittrunyon

After revisiting the timing.....
...........there is no F mark
..........not ready to bend any tabs in the bean can just yet

At 1000 rpm's the OT & S marks are below the window
.................(the OT mark is above the S mark on the same tab, on the fly wheel)
.................the OT mark can be seen at the bottom of the window but the S mark is out of sight
.................the bean can is advanced (counter clockwise) as far as possible

At 3000rpm's there is "nothing" showing steady in the window

There's no Z mark showing anywhere between 1000 to 4000 rpms.

It rides just OK, doesn't rattle, but as I stated earlier it's a gutless beast which I attribute to old electronics.......maybe?

Electronics ain't like bread. The work or they don't.

Coils might be weak and/or wires bad. Check your sparks (carefully, run a HT lead open and you trash the ignition immediately)

Timing could be way off. So resolve that.

Check compression.

If a valve job only lasted 41k miles something is very wrong. possible with the person doing that work. And why were the jugs replaced?

You don't have to take the bean can apart to service the advance weights. You do it through the service window. Did you return the can to the same place on the block where it was when you took it off?

How did you balance the carbs by the shorting method? If it's smooth you're likely good there but do some plug chops to check mixture.

[brittrunyon]

Originally Posted by Plaka

Electronics ain't like bread. The work or they don't.

Coils might be weak and/or wires bad. Check your sparks (carefully, run a HT lead open and you trash the ignition immediately)

Timing could be way off. So resolve that.

Check compression.

If a valve job only lasted 41k miles something is very wrong. possible with the person doing that work. And why were the jugs replaced?

You don't have to take the bean can apart to service the advance weights. You do it through the service window. Did you return the can to the same place on the block where it was when you took it off?

How did you balance the carbs by the shorting method? If it's smooth you're likely good there but do some plug chops to check mixture.

For sure, you can't put peanut butter on electronics, but I think corrosion like peanut butter can restrict the spark.

I agree timing is first.

The valves & valve guides were done 4,000 miles ago, as stated above, not 41,000 miles, that was the first time.
I have no idea why the cylinders were replaced.

I did return the can back to it's original location.
What is the service routine for the advance weights through the window?
What lube should be used?

I balanced the carbs the way I always have but according to you on another thread I did it wrong, so I'm still waiting for an update on the proper procedure.
Is plug chops like pork chops?

So there's no Z mark in the window.
What's up with that?

Thanks for your input.

[Plaka]

Originally Posted by brittrunyon

For sure, you can't put peanut butter on electronics, but I think corrosion like peanut butter can restrict the spark.

You can use peanut butter but toothpaste works much better. Real heatsink paste is the class act and washes off well. This is for soldering, you use a very different type of heatsink paste under the ignition module and it should be renewed annually.


Remove corrosion from all connections. Air eraser running baking soda.

I agree timing is first.

The valves & valve guides were done 4,000 miles ago, as stated above, not 41,000 miles, that was the first time.

I meant how long that first valve job lasted.

I have no idea why the cylinders were replaced.

I did return the can back to it's original location.
What is the service routine for the advance weights through the window?
What lube should be used?

Open window and discard cap. Turn unit so pivot is in window, squirt of brake cleaner with window facing down so it drains. You want to get the pivots only as best possible. it's all plastic bushings in there, I would use a silicone grease on the backer plate and silicone oil on the pivots. I used the first thing I grabbed which was Mobile 1 synthetic grease. Close the window with aluminum foil tape

I balanced the carbs the way I always have but according to you on another thread I did it wrong, so I'm still waiting for an update on the proper procedure.

http://www.eskimo.com/~newowl/settin..._CV_carbs.html

Is plug chops like pork chops?

No.

So there's no Z mark in the window.
What's up with that?

Somebody moved the window? Walk the flywheel around by hand and clean +paint all the marks. Whiteout works OK and comes in a bottle with a handy brush. Paint on, dry, scrub off. Brake cleaner prep and go light, you have a clutch disk in there.

Thanks for your input.