IT RUNS..IT RUNS.......but....

[Garnet Grylls]

Good Morning to All!

After taking some pictures of my rocker arm oilers, I got some petrol and installed the tank and started on the third kick . All sounded good  and I did a couple laps of the parking lot .

The points where untouched from when I took the dynamo off but I thought I should check the timing anyway. (It was idling very fast). It showed very advanced, almost at the F mark . When I set the points back, the bike would only start if I pushed it, and had no power to pull itself . After playing around for an hour it seems to only run with spark much too early.

When I was setting the cam timing I checked that the flywheel marks matched actual OT. Now I have to sleep on it and see what else i can think of.

Greetings
Garnet T(oo advanced for my own good)

P.S.  It seems to vibrate a lot at idle and up to about 1500 and then gets much smoother than it was before . I will post the pics of the oilers when my friend emails them to me.

[Garnet Grylls]

[Garnet Grylls]

Good Day,

I have spent some time playing with the points but still can only make it run at around 7 - 10 deg. before the S mark. It starts well cold but when hot it backfires and kicks backwards. If I move the points back just slightly it barely runs and has no power. Another couple degrees back and it will not run period, Even if pushed.

When running in the advanced position it is quiet with no pinging sounds, and seems normal. The too fast idle was my new throttle cable holding the carb open (now fixed).

I wonder if my new 9 deg advanced cam timing is having some effect. I don't know why the valves opening and closing sooner would cause the need for earlier spark.

Greetings
Garnet

[Rütz]

Hi Garnet,

sounds to me like a defect of the centrifugal advance, at the first glance....

How do you check the points, statically or with strobo?
You can't check the "S"-point with a strobo while the engine is idling ('cause the advancing has already begun).

Where is your F-point coming to stay? Measured with a strobo or statically while the flyweights are manually spread.

Maybe you need a 2-3 deg. different point with a tuned engine, but never 7-10 deg.. I think it's an artefact...

Greetings
Anselm N(o idea..)

[Garnet Grylls]

Hey Anselm,

Yes I am using a srtobo. I installed a degree wheel and found that it is firing at 49 deg at maximum advance. So it is 7 deg too far. I may install temporary blocks in the centrifugal advance so that it will not go past the F mark, so I can go out on the street to "break in" the engine.

I installed the degree wheel to confirm that the OT marks matched real OT. As you know, you must stop the piston near the top of its travel and take reading on the wheel and then turn the engine back the other way until the piston touches the stop again. Half way between the two stops is true OT.

While trying to figure out how to make a piston stop without removing the head, I tried holding a pencil down the spark plug hole. As I turned the engine I heard a CLICK......I broke the %$@#ing pencil off in the cylinder.  (It was actually very funny)

Now I had a good reason to take the head off and got a good acurate measurement. The OT mark on my flywheel is off one and a half degrees.

Now that I know when the spark is really happening I can begin to work around it.

Cheers
Garnet K(ing of head gaskets)

[Rütz]

At least with R27 it's a common problem that the timing range of the advance is greater than stated. Mostly rather 40 than 35 deg.

Just to be sure... :

you don't use these  french degree wheels   in Canada, which have 400 deg on a circle instead of 360 ?


Anselm S(_ystem I_nternational)

[rolf]

Hallo garnet,
your system with a pencil to controlate the OT wasn't perfect, you could easily(!!) have a disalignment of 20°.
Why you don't use the system BMW said: Piston at OT (by only controlling by the flywheelmarks, there you must have  the Stößelstangen (time for YOUR dictionary) parallel to the Cylinderhead, that is accurate enough. The OT must be the Überschneidungs (dictionary!)-OT.
As Anselm said, if the engine runs, you can forget the "S" mark, this is really only for static, aonly a few RPM'S and it goes towards "F".
The only important mark is "F"
If there are too much degrees between "S" and "F", old springs or worn out centrifugal advance (or bad adjustment of the springs)
Rolf P(idgin)

[Rütz]

Hi Rolf, you alzheimist !

The OT must be the Überschneidungs (dictionary!)-OT.

This is only correct, when you have original timing and the original camshaft!!

But Garnet has "feintuned" his valvetiming by mounting the camshaft sprocket (Ritzel) without the "Scheibenfeder", so he could tighten it in (to him) optimal position.
Thus the "Überschneidungs"- upperdead is not exactly at "Überschneidung" (valvecrossing?) anymore in his R26.

Anselm D(oublepidgin)

[Garnet Grylls]

Anselm:

No I don't have one of those fancy new "French 400 deg wheels". I have an old fashioned American (comes with handgun) wheel .

Rolf:

I have a good set of advance springs out of my zweizylinder and will use them to rebuild my einzylinder advance.

Garnet M(etric degrees)

[† odeon8]

Hi Garnet,

are you sure about 2 items:

1. Does your new camshaft alignment (9° advance) refer to crankshaft degrees ?
2. The boxer springs might be different to the onecylinder springs because
    they are designed to be operated with camshaft speed ...?

Tom F(aithless)

[Garnet Grylls]

Hi Tom

1.Yes the cam is advanced 9 crankshaft degrees.
2.The part numbers of the springs are the same for the single and twin cylinders.

It is good to not have too much faith in someone who would stick a pencil down his (spark plug) hole .

Garnet

[Garnet Grylls]

Good Morning Everyone,

I used the advance springs from my 1967 R60/2 and found them to be 9mm. I also lightend the advance weights a few grams and now pass the F mark at 3000 UPMs and reach maximum advance of about 50 degrees at just under 5000 UPMs.

The bike pulls with strength from idle to 40 KMPH in second gear . I can hardly wait for some dry weather to go out on the road , maybe on the weekend.

Greetings
Garnet

[rolf]

Hey Garnet, I hope you have still bad weather!
It's not correct that you reach 50°,
you have to Reach "F" (and perhaps a few(!) degrees more) at roundabout 3000-3500 UPM's and then it had to stop! This is the max UPM's for shifting!! More UPM'S-no more degrees!
You could have pinging at full power, but I'm afraid you could not hear it, you could try to test ist.
The only thing I want to say is that at 3000-35000 is the end of moving the "F" point.
Many People think that after  this UPM's the "fire-point" have to move more forwards together with the UPM's, that isn't correct. The max is at 3000-3500.
Greetings
Rolf

[Garnet Grylls]

Hi Rolf,

It is a nice sunny dry day and I am going down to the shop to start all over again :-[. I have talked to many local mechanics who can give me no good answer to my problem. But they have all said that 50 deg is too far for any engine.

I will start by adjusting the valves very tight (to mimic advanced cam timing) and then very wide (to mimic retarding cam timing) to see if this has any affect.

I will then try an automotive coil and condenser to see if there is any problem with the spark or wiring.

Garnet S(chrauber-Lehrling)

[Garnet Grylls]

OK Rolf, you won

Sometimes I need a swift kick from behind to keep me on track. I spent a long time carefully going over the entire ignition system. I tried running with very wide (.4 mm) valve clearance and no clearance at all. Nothing seemed to change.

Next I glued blocks in the advance to stop the movement of the springs sooner. After much trial and error I now stop at the F mark at about 3400 UPMs.

It is supposed to be sunny again tomorrow so I'm going ridding. I will have to stop and check to see if my "blocks" stay in place.

Greetings
Garnet B(locking great advances)

[rolf]

Hey garnet,
good luck tomorrow!

Why you have lightened the advance wheights?
You know that they now going later to "F"?
)mm springs? you must have a 11mm and a 9mm spring for the original R26 advance
(Heiko has spent a photo of the 26 advance where you can see the two differnet springs , under "Fliehraftregler")
Rolf W(inner)

[Heiko]

  It´s a pic from my special 120km/h advance!

[rolf]

you can found it under:
Ersatzteile
Gesuche
Fliehkraftregler

Heiko, I think that you better send a photo of your speedometer, that could be able (perhaps) to explain truly your 120 km/h tale!!

Mann, vermisse ich Markus, ich habe 15 min gesucht wo das Foto sein könnte!

[Garnet Grylls]

Hello Rolf

I originaly took some weight (not much) off the advance to make it reach F later. But now I have seen the light, so I used less preload on the springs to get F at lower UPMs.

My advance is the style that uses 2 same length springs. Since I only want to go 115 kph I will not need to use Heiko's "special" advance.

Garnet B(linded by the light)