New Project

[Stirlingmoz]

So while the carb body is soaking in penetrant I decided to remove the left cylinder head.

And the the cylinder and piston.

There is a bit of dirt right at the top but the hone marks are still clearly visible

And removed

Ring end gap is a bit excessive at 0.8mm.

Will order some new rings hoping they’re sacrificial and the cylinder is still good.

Piston, valve gear and pushrods all in good condition. Conrod feels lovely. I can see some of the cam and it all looks good inside.

The followers are in good condition too

A closer inspection of the cylinder head revealed excessive wear in the exhaust valve guide.

Though the head has been twin plugged, the top / primary plug thread has clearly been repaired.

Seems to be a decent job though.

Need to find someone to the valve guide for me.

 

[tuftywhite]

Mikeyboy fits them.

 

[Stirlingmoz]

Just noticed looking at the photographs above, the casting for the cylinder head is 1977 so not original to this engine.

I've checked the cylinder barrel with a magnet and its definitely not magnetic so I am assuming that is year correct, nikasil.

It's only the modified head which doesn't tally.

The engine covers all date similarly.

 

[Stirlingmoz]

The holy grail

Managed to get hold of a complete G/S headlight assembly with a left dip. Mounting brackets and gaskets all included.

Needs a clean up but hopefully will get it fitted at the weekend.

 

[Bubb]

You did well finding the correct headlight bits…..thought they were now “unavailable”
I was lucky that when I did my st t9 gs conversion the headlight ring and gasket were still available from BMW….didn’t cost a fortune either !

The rebuild is going well.

 

[Stirlingmoz]

Motorworks do list some headlight parts including a pattern glass but no mounting bracket.

This wasn’t cheap but its all original and where am I going to find another ?

I’ve just bought a battery so I’m close to checking the wiring and seeing the bike slowly come to life.

Being colour blind, I always dread wiring so will have to involve friends and family to check my work.

 

[dr nosh]

When you layout your wiring harness could you not put numbers on each of the cable, 'aided by a suitable adult'

Like this:

Thread On Plastic Cable Markers

Thread On Plastic Cable Markers

www.vehiclewiringproducts.co.uk

Then with those in place, and checked, you can work at your own pace.

 

[Stirlingmoz]

Good shout.

Like anyone with a disability (albeit this one is very minor) you kind of adapt.

I can see some colours but red, green and brown are my nemesis. My wife and I now make a good tag team with wiring diagrams - particularly Haynes ones

 

[Stirlingmoz]

Do you remember that snapped jet holder ?

There’s a photograph on page 4 where the top sheared off when I tried to remove it.

Well the carb has been soaking in a bath of penetrant and this bit has been through many heat cycles.

The ‘easyout’ finally got it to move.

Just a gnats but it was enough to let me work it back and forth.

Today…

It’s finally out and I think the internal threads survived.

Phew I can get on with the refurb now.

 

[Stirlingmoz]

We have some progress on the electrical front.
With a new Exide battery fitted I made up a temporary earth lead to the frame as there is no engine / gearbox for the stock cable to connect to.

We now have:
Lights / brake lights
Indicators
Warning lights
Horn
Clicking starter relay

I think the clutch interlock thingamajig switch is playing up so I need to test that.

I also think the rubber headlight gasket may be fitted incorrectly. A bit pokes out the front of the black plastic fairing which looks wrong / awful.

One of the carbs is now completely cleaned and rebuilt (right side)

I did them one at a time so I have a reference.

Time to strip the left side carb now

 

[Stirlingmoz]

A quick update on the G/S.

It’s starting to look like a bike now

Chuffed to find a headlight and it’s now fitted correctly. I had the rubber sealing gasket in wrong first time

All the frame electrics are now in and working and I only popped 2 fuses. That’s good for me.

I really need to crack on with the engine now

If anyone has a bead on the sump mounted bash plate, I’d be interested.

That’s probably the biggest part eluding me now.

 

[Stirlingmoz]

So it’s time to fire up the barbie.

Not to make sausages though.

I’m going to have a go at driving out the worn exhaust valve guide.

This is the pre cylinder head cooking set up.

What could possibly go wrong ?

 

[Stirlingmoz]

After 30 mins in the barbie followed by a couple of firm thwacks and the old exhaust valve guide is out.

While the head was still really hot, I got the new valve guide out of the freezer. This took about 3 good hits to drive home.

But it’s in. The head is now cooling off slowly on the bench.

Will offer the exhaust valve up later and check the fit.

If the left cylinder head is worn, I strongly suspect I’m going to have to do this job again on the other side.

Do most people pop both cylinders off at the same time ? I tend to remove and refurb one side at a time. Don’t know why - just habit

 

[Gelandestrasse]

A quick update on the G/S.

It’s starting to look like a bike now

Chuffed to find a headlight and it’s now fitted correctly. I had the rubber sealing gasket in wrong first time

All the frame electrics are now in and working and I only popped 2 fuses. That’s good for me.

I really need to crack on with the engine now

If anyone has a bead on the sump mounted bash plate, I’d be interested.

That’s probably the biggest part eluding me now.

BMW R100GS R80GS R80G/S R80GS genuine sump guard 2315345 | eBay

Early type sump guard in good used condition with fittings. Motorworks UK are the UK's largest independent supplier of new and used parts for BMW motorcycles. Don't be afraid to ask if you require any further information regarding a listed item.

www.ebay.co.uk

 

[Stirlingmoz]

Appreciate the steer but I’m looking for the even earlier version of the sump guard.

Like this one..

 

[Mzokk]

Motorworks do list some headlight parts including a pattern glass but no mounting bracket.

This wasn’t cheap but its all original and where am I going to find another ?

I’ve just bought a battery so I’m close to checking the wiring and seeing the bike slowly come to life.

Being colour blind, I always dread wiring so will have to involve friends and family to check my work.

I know the feeling its a nightmare playing snooker as well. Fantastic job so far

 

[rocky burns]

Appreciate the steer but I’m looking for the even earlier version of the sump guard.

Like this one..

German ebay is the best place to look.

 

[Gelandestrasse]

Appreciate the steer but I’m looking for the even earlier version of the sump guard.

Like this one..

BMW R100 GS R80 GS G/S Unterfahrschutz Ölwanne Schutzblech 1242295 | eBay

Unterfahrschutz/Schutzblech für Ölwanne BMW R80G/S / R80GS / G100GS. Geringe Kratzer/Macken können vorhanden sein. BMW Nr 1242295. Underrun protection / protection plate for oil pan BMW R80G/S / R80GS / G100GS.

www.ebay.co.uk

 

[scooter paul]

Appreciate the steer but I’m looking for the even earlier version of the sump guard.

Like this one..

I think I’ve got one amongst my G/S spares. I’ll look.

 

[Stirlingmoz]

A few minutes lapping valves in the old fashioned way with a sucker on a stick.

This is as good as I’m going to achieve in my shed.

A bit redneck compared to some of the engineers on here.

My rudimentary tests include a lovely loud vacuum pop pulling the valves out of the guides and filling the head with fuel - none leaked out.

That’s good enough for me.

Time to order some sealant and this can all go back together. Next weekend - fingers crossed