On Jun 30, 2020, at 6:07 PM, andrew.romero@... wrote:

Phil, Mac, Richard, Joe and William,

First of all I want to thank you for the considerate responses.? I appreciate all the angles.? The only thing better than the creativity allowed by these machines is the amazing community that surrounds them.?

I am realizing that I really need to shed my fear and dive in and do this project myself.? That is the only way I feel like I can be sure of the outcome.? your exposure of the mechanic's bad advice has shaken my faith, and quite frankly, i seem to have had a bad run of trying to find a decent airhead mechanic locally, that is neither a cheat, a fraud, or just plain surly.?

This will be a new airhead frontier for me.? After years of watching videos, reading Snowbum and Brook, and most recently finding the boxer 2 valve videos amazingly soothing during this pandemic. (Thanks William), i feel like I am ready.?

I believe that a new set of pistons and cylinders are the best course of action. I will go the Seibenrock route,

...although a quick perusal of ebay led to the discovery of what looks like a NOS set of cylinders and pistons for 75 and earlier r90/6.?

I am attaching link.


I searched the number referenced and although information is lost in the german translation of the ad, i believe the items for sale are the NLA cylinder piston set for the r90s up to 75 (1100 1260322)

would have been an easier decision had i not found those, then again, maybe after i sleep on it, they will be gone.?

Again, my thanks to you all, I am sure I will lean on you again.?

Warmest regards,
Andrew?

On Jun 30, 2020, at 9:22 AM, Joe Dille <joe@...> wrote:

?Plan B would be to get the cylinders plated to the correct size and bored
for your current pistons. You get to keep your existing cylinders and
don't need new pistons.



Ride Safe,

Joe

Andrew, I am told that boring cylinders will leave the wall thickness too
thin and you will run into heat and warping issues. I restored an R90S
some
years ago and at that time I did not know about the Siebenrock 1,000 kits,
which will fit certain model year R90Ss. If I recall correctly, BMW made
the hole in the side of the block larger starting with 9/75 production,
which was the start of the '76 model, in preparation for the '77 1,000 cc
engines.

So I think you can install that Siebenrock 1,000 kit. I have that kit on
my
R80G/S and it is quite good, I'm glad I installed it.

Not sure where you are located, but boxer2valve in NC sells the Seibenrock
kits,


I am including William Plam from boxer2valve in this conversation so he
can
clarify this for you in a return email. He is very helpful.


Mac Kirkpatrick
Glenmoore, PA

"After all, what is adventure, but inconvenience, properly regarded?"
C. Donahue

On Tue, Jun 30, 2020 at 10:15 AM <andrew.romero@...> wrote:

hello,

i have a 75 r90s that needs top end work, my local bmw mechanic is
recommending boring out the cylinder to fit a 1000cc piston to increase
performance. since this is the 75 year model with 97mm and not the
fatter
99mm i am hesitant as i have not found anything online documenting a
bore
out of the smaller cylinders. Just looking for some guidance, thank you
in
advance.

--
Joe Dille
Telford PA


What happens on earth stays on earth

?

Andrew, I am told that boring cylinders will leave the wall thickness too
thin and you will run into heat and warping issues. I restored an R90S
some
years ago and at that time I did not know about the Siebenrock 1,000 kits,
which will fit certain model year R90Ss. If I recall correctly, BMW made
the hole in the side of the block larger starting with 9/75 production,
which was the start of the '76 model, in preparation for the '77 1,000 cc
engines.

So I think you can install that Siebenrock 1,000 kit. I have that kit on
my
R80G/S and it is quite good, I'm glad I installed it.

Not sure where you are located, but boxer2valve in NC sells the Seibenrock
kits,


I am including William Plam from boxer2valve in this conversation so he
can
clarify this for you in a return email. He is very helpful.


Mac Kirkpatrick
Glenmoore, PA

"After all, what is adventure, but inconvenience, properly regarded?"
C. Donahue


On Tue, Jun 30, 2020 at 10:15 AM <andrew.romero@...> wrote:

hello,

i have a 75 r90s that needs top end work, my local bmw mechanic is
recommending boring out the cylinder to fit a 1000cc piston to increase
performance. since this is the 75 year model with 97mm and not the
fatter
99mm i am hesitant as i have not found anything online documenting a
bore
out of the smaller cylinders. Just looking for some guidance, thank you
in
advance.

On Jun 30, 2020, at 8:04 AM, Mac Kirkpatrick <drbeemer73@...> wrote:

?

Andrew, I am told that boring cylinders will leave?the wall thickness too thin and you will run into?heat and warping issues. I restored an R90S some years ago and at that time I did not know about the Siebenrock 1,000 kits, which will fit certain model year R90Ss. If I recall correctly, BMW made the hole in the side of the block larger starting with 9/75 production, ?which was the start of the '76 model, in preparation for the '77 1,000 cc engines.

So I think you can install that Siebenrock 1,000 kit. I have that kit on my R80G/S and it is quite good, I'm glad I installed it.

Not sure where you are located, but boxer2valve in NC sells the Seibenrock kits,

I am including William Plam?from boxer2valve?in this conversation so he can clarify this for you in a return email. He is very helpful.

Mac Kirkpatrick

Glenmoore, PA

"After all, what is adventure, but inconvenience, properly regarded?"
C. Donahue

On Tue, Jun 30, 2020 at 10:15 AM <andrew.romero@...> wrote:

hello,?

i have a 75 r90s that needs top end work, my local bmw mechanic is recommending boring out the cylinder to fit a 1000cc piston to increase performance.? since this is the 75 year model with 97mm and not the fatter 99mm i am hesitant as i have not found anything online documenting a bore out of the smaller cylinders.? Just looking for some guidance, thank you in advance.?

On Jun 30, 2020, at 10:15 AM, andrew.romero@... wrote:

?hello,?

i have a 75 r90s that needs top end work, my local bmw mechanic is recommending boring out the cylinder to fit a 1000cc piston to increase performance.? since this is the 75 year model with 97mm and not the fatter 99mm i am hesitant as i have not found anything online documenting a bore out of the smaller cylinders.? Just looking for some guidance, thank you in advance.?

On Jun 17, 2020, at 09:12, Mac Kirkpatrick <drbeemer73@...> wrote:

?

Besides?speedos needing refurbishment after many miles and years, the instrument lights in my dash were wonky as well.?

Installing the KatDash LED replacement instrument lights made a HUGE improvement, I can now see the lights even in the sun:

Mac Kirkpatrick

Glenmoore, PA

"After all, what is adventure, but inconvenience, properly regarded?"
C. Donahue

On Wed, Jun 17, 2020 at 9:05 AM Frank ---Down Under <r90s@...> wrote:

I had the same problem with my S, the odometer had?a mind of it's own. It happened just at the right time because I had planned to take the instrument to a specialist to have it re-calibrated. The?gear had literally wore itself to a point that it was hardly?made contact. The specialist replaced the gear, then calibrated the instrument and knowing?the gearing ratio plus miles covered working it out that the gear?had, in its lifetime, spun?371,349,000 times.

On Wed, Jun 17, 2020 at 8:15, Mac Kirkpatrick

<drbeemer73@...> wrote:

Besides?speedos needing refurbishment after many miles and years, the instrument lights in my dash were wonky as well.?

Installing the KatDash LED replacement instrument lights made a HUGE improvement, I can now see the lights even in the sun:

Mac Kirkpatrick

Glenmoore, PA

"After all, what is adventure, but inconvenience, properly regarded?"
C. Donahue

On Wed, Jun 17, 2020 at 9:05 AM Frank ---Down Under <r90s@...> wrote:

I had the same problem with my S, the odometer had?a mind of it's own. It happened just at the right time because I had planned to take the instrument to a specialist to have it re-calibrated. The?gear had literally wore itself to a point that it was hardly?made contact. The specialist replaced the gear, then calibrated the instrument and knowing?the gearing ratio plus miles covered working it out that the gear?had, in its lifetime, spun?371,349,000 times.

On Jun 16, 2020, at 7:33 PM, flx 1948 <flx48@...> wrote:

Hi David-

When was the last time the speedo was cleaned and serviced?

Sounds like that's the issue, but if its been serviced recently, then perhaps there is a mechanical problem.

Best-

George

---

From:?[email protected] <[email protected]> on behalf of DAVID LEMAIRE via <dslemaire@...>
Sent:?Tuesday, June 16, 2020 5:45 PM
To:?[email protected] <[email protected]>
Subject:?[R90SWORLDNET] odometer issues on 90/6

?

I have a 1976 R90/6 and it’s recently had some strange issues with the odometer.

The speedometer works just fine, but recently I looked down at the odometer and it wasn’t turning.? Even stranger, it was showing about 40,000 miles on it when it was working.? When I looked down today it was showing 950!??

I rotated the tripmeter to zero it out and drove around several miles.? It moved, but only by .6 miles.? And now the odometer is showing over 70,000 miles!

Something is very strange.

I removed the cable and it seems to spin normally with the bike in drive and the wheel spinning.? And the speedometer seems normal.? Other than a little vibration.

Any suggestions?

Thanks,

David LeMaire
Trumbull, CT.

On 17/06/2020, at 2:51 PM, Joe Dille <joe@...> wrote:

?
This happens to the odometer on these bikes. The little wheel that drives
the odometer wheels comes loose from the shaft and the whole thing becomes
a random number generator. This happened to me 20+ years ago. I took the
speedometer apart and put a drop of super glue on the offending wheel.
All better since then. A speedometer shop sould do the same thing.

Ride Safe,

Joe

Hi David-
When was the last time the speedo was cleaned and serviced?
Sounds like that's the issue, but if its been serviced recently, then
perhaps there is a mechanical problem.
Best-
George


________________________________
From: [email protected] <[email protected]> on behalf of DAVID
LEMAIRE via groups.io <dslemaire@...>
Sent: Tuesday, June 16, 2020 5:45 PM
To: [email protected] <[email protected]>
Subject: [R90SWORLDNET] odometer issues on 90/6

I have a 1976 R90/6 and it’s recently had some strange issues with the
odometer.

The speedometer works just fine, but recently I looked down at the
odometer and it wasn’t turning. Even stranger, it was showing about
40,000 miles on it when it was working. When I looked down today it was
showing 950!

I rotated the tripmeter to zero it out and drove around several miles. It
moved, but only by .6 miles. And now the odometer is showing over 70,000
miles!

Something is very strange.

I removed the cable and it seems to spin normally with the bike in drive
and the wheel spinning. And the speedometer seems normal. Other than a
little vibration.

Any suggestions?

Thanks,

David LeMaire
Trumbull, CT.

--
Joe Dille
Telford PA


What happens on earth stays on earth

Hi David-
When was the last time the speedo was cleaned and serviced?
Sounds like that's the issue, but if its been serviced recently, then
perhaps there is a mechanical problem.
Best-
George


________________________________
From: [email protected] <[email protected]> on behalf of DAVID
LEMAIRE via groups.io <dslemaire@...>
Sent: Tuesday, June 16, 2020 5:45 PM
To: [email protected] <[email protected]>
Subject: [R90SWORLDNET] odometer issues on 90/6

I have a 1976 R90/6 and it’s recently had some strange issues with the
odometer.

The speedometer works just fine, but recently I looked down at the
odometer and it wasn’t turning. Even stranger, it was showing about
40,000 miles on it when it was working. When I looked down today it was
showing 950!

I rotated the tripmeter to zero it out and drove around several miles. It
moved, but only by .6 miles. And now the odometer is showing over 70,000
miles!

Something is very strange.

I removed the cable and it seems to spin normally with the bike in drive
and the wheel spinning. And the speedometer seems normal. Other than a
little vibration.

Any suggestions?

Thanks,

David LeMaire
Trumbull, CT.