What a Day!......What a ****?*****?...

[Rob Farmer]

Michelle,

I'm sure with you doing the work you're going to end up with a really well sorted bike after this. I know you have a lot on but is there any chance you could take some pictures of the rebuild and post them in the Airhead Tech section?

Thanks

Rob

 

[Lilith]

I'm sure with you doing the work you're going to end up with a really well sorted bike after this. I know you have a lot on but is there any chance you could take some pictures of the rebuild and post them in the Airhead Tech section?

I already have this planned

I will put together a full technical sheets for the jobs, as I rebuild. I will do this thread, but extend into the tech section.

 

[Lilith]

Update

Just in the middle of changing the engines over at the moment, but I am still waiting for some new parts so going slightly slower than expected but I will get there.

We think we have found the reason for the bent con-rod, when stripping the old engine and after removing the crankcase studs to the bent con-rod side, we found that it had been heli-coiled on the front two studs and one rear. So it looks like it has been in an accident or dropped and damaged at some point in its life. So we have guessed that the con-rod was never changed at this point and the damage finally took its toll.


Oooooops


What you do not want to find in your sump

 

[Lilith]

Heli-coils …… your thoughts please

As part of the re-build BamBam and myself were going to use the original crankcase and the spare crank and con-rods that we pick up from Rob to make a spare engine.

But given we have found heli-coils in the crankcase the question is would you use the case again as this work has been carried out Cain says no, as he has already done this before but they have pulled out on this R100RS.


So what do you guys think.....


Michele

 

[Rob Farmer]

It's not uncommon but I don't know how well they stand up after being helicoiled. There shouldn't be a problem but you never know?

If you have a nice word with Uncle Proff (Don't sit on his knee though - he's like an octopus ) I gave him a set of G/s crankcases with intact studs a while back and I would imagine they are sitting with the rest of his hoard gathering dust. I spoke to him at the weekend and he did mention he'd help out if you had a problem. Send him a PM.

I got the book BTW. Thanks. Just having a read at the minute. I'll get it back to you next weekend.

 

[(RIP) Proff]

Helicoils are quite common on late Airhead Crankcases
they seemed to change to Monkeymetal in late 80's.
I've never had a stud thread pull out on my Crankcases and they range from 1952 to 1985....
the R100GS we got for Monk last year has had a '85 100 RT engine put in and it's so much better quality crankcases when you have engines side by side

 

[Steptoe]

Helicoils are quite common on late Airhead Crankcases
they seemed to change to Monkeymetal in late 80's.

So common that BMW lowered the torque for the cylinder head studs.

It was a combination of metal quality and the original BMW machinery that cut the threads in the block. It was worn out and they couldn't be arsed changing it so near to the end of production.

helicoils are fine. Wurth timeserts are better. Remember to drill the them for the rocker oil feed.

 

[(RIP) Kaister]

So common that BMW lowered the torque for the cylinder head studs.

It was a combination of metal quality and the original BMW machinery that cut the threads in the block. It was worn out and they couldn't be arsed changing it so near to the end of production.

helicoils are fine. Wurth timeserts are better. Remember to drill the them for the rocker oil feed.

Metal is cast to a standard described firstly on a drawing and tested to manufacturing quality standards as approved by the purchaser. If they want a certain type of aluminium they will get it - if they choose to change it, usually for cost purposes, they will get that also )

Machinery that cuts threads - commonly called a 'milling machine' - has replacable cutting tools ( breakages occur daily ) - commonly called 'taps'.

Old wives tales , i'm afraid.

Now - if you'd said the casting patterns were worn out, i might have believed you.

However, wurth timeserts are much better than helicoils given there is enough surrounding metal to attach to

( however, however - in an F1 car a wurth timesert is considered far too heavy and a helicoil is preferred )

 

[nud1e]

helicoils are fine. Wurth timeserts are better. Remember to drill the them for the rocker oil feed.

Steps can you explain further on

Remember to drill the them for the rocker oil feed.

 

[Steptoe]

.

Old wives tales , i'm afraid.

The bloke down the pub told me so it must be true.

Steps can you explain further on

The oil for the rocker shafts is fed through the top threads in the block. Just a little way in the thread you can see the oilway, so when you use an insert you'll cover up the oilway, starving the rocker gear of oil.

You need to drill the insert at the point where the oilway feeds.

 

[Lilith]

Cheers for all your opinions, will keep in mind

 

[(RIP) pastyman]

One more thing for you to consider if you use the original cranckcase, with all the swarf from the helicoil, you should check or renew the oil pump. When mine was rebuilt there was considerable damage to the pump by the bits of bearing material. In fact even the timing chain was renewed for the same reason even though it had only been in for a couple of months.

 

[Lilith]

One more thing for you to consider if you use the original cranckcase, with all the swarf from the helicoil, you should check or renew the oil pump. When mine was rebuilt there was considerable damage to the pump by the bits of bearing material. In fact even the timing chain was renewed for the same reason even though it had only been in for a couple of months.

Cheers,

Will be rebuilding the orginal engine hopefully in May, as the short engine is going in the bike shortly as we should be going away at the end of the month. But with all of these tasks when you are in a hurry you end up waiting for parts

 

[deaninkl]

Sorry for your woes, but before anyone else says it...

Welcome to the world of airheads, welcome to my world!

I was just looking in from the 12 forum.... been thinking about a very nice gs800 being sold locally, as I have been harking for a simple life... but I notice here that they are all pretty much the same.... wowbe'em

 

[peepingtom]

hey lilth sorry to here of your troubles hope that its gunna be fine. life is just a bitch sometimes .good luck with your trip

 

[Lilith]

The nightmare continues

Finally got the bike together and working on Sunday/ Monday

On Monday I got knobbly tyres fitted – my first time on true knobbles, oh what fun

On Tuesday Cain and myself planned to go and do the trip across the Pyrenees as we had planned when we got the bike. (you might all think it is a bit fast but I start a new job in a couple of weeks, so it is the only holiday that we are going to get for awhile)

We left home Tuesday afternoon and had a good run to the Eurotunnel. Bike running well, no smoke no rattles – Brilliant

Then it all started going wrong

Got a ticket for the train, tried to start the bike – no start, battery dead

At this point I had to move the bike, with all the gear on, I cannot get off the bike, so in Cains words I looked like a short legged duck with constipation, using one leg to move.

Several bump starts later, Me very hot and very annoyed on the train. I must also point out that we were on the back of the train!!!!!!!

Got to France

Pushed the bike from the back of the train to the platform, Cain was polite and pushed his bike of the train to. Me even hotter and even more annoyed.

Eurotunnel staff had called their rescue man to jump start the bike. We also located a hotel nearby at City de Europe. Rescue Man arrived and started the bike. But in true silly style I stalled the bike so Rescue Man and Cain pushed the bike, it started and I was off pulling a wheelie and leaving Cain behind without a bye or thanks. I went straight to the hotel and sat on the bike waiting for Cain to help me get of the bike. Apparently the Rescue guy was impressed with a fully kitted up GS popping a wheely.

Question: Who put the side stand under the cylinder?
Answer: A sadistic ****

Anyway two nights in two of the three hotels, swapped in the spare new diode board still not charging. Then the new rectifier, no go…… took the rubbers out, made 2 rubber washers for the bottom mounting points and solid mounted the diode board as this had been a problem on Sunday night…hence the rubber mounts and not hard mounted..
We now have a charge.

The next problem was Cain was left with a dud battery, so located Euro Touring (BMW) in Calais, and got a new battery. The supermarket in the shopping complex sells batteries but they were not big enough.

The next day we came home, at this point the starter motor is now making silly amounts of noise……..

The story Continues………

 

[Lilith]

The next part of the saga

Today we planned to go to Wiltshire as we failed to get to Spain, for some lovely camping and off-roading…….We left Cambridge and got Baldock

The current problem that is now plaguing the bike is when riding at about 70 mph the oil light flashes 2 to 3 times and then goes away……. Further down the road……..oil light flashes….. goes away.

We are now back home.

Oil light functions correctly on start up, no smoke, no oil leaks blah blah blah

Any thoughts for a remedy etc gratefully awaited…… as we would like to go away

 

[nud1e]

Today we planned to go to Wiltshire as we failed to get to Spain, for some lovely camping and off-roading…….We left Cambridge and got Baldock

The current problem that is now plaguing the bike is when riding at about 70 mph the oil light flashes 2 to 3 times and then goes away……. Further down the road……..oil light flashes….. goes away.

We are now back home.

Oil light functions correctly on start up, no smoke, no oil leaks blah blah blah

Any thoughts for a remedy etc gratefully awaited…… as we would like to go away

Welcome to the joy of airheads.

Check the connection to the oil pressure sensor, check the wiring from the connection, replace the switch. I had to replace the sensor on my 80GS, fortunately I could take one from my R75/6 which proved that the 80 sensor was defective.

 

[Lilith]

Thanks

Check the connection to the oil pressure sensor, check the wiring from the connection, replace the switch. I had to replace the sensor on my 80GS,

Will be doing this tomorrow

Luckily we have a spare sensor.

 

[Duncan Richmond]

Hi,

I have a 88 800GS. I had the cylinder stud problem years ago, they just pulled the threads out of the crankcase (2 on each side) My mate who is a highly skilled engineer carried out the helicoil repairs but they didn't last very long, the whole lot just came adrift again. I gave up with the original crankcase and shifted all the internals into a S/H 1981 crankcase and all has been OK for the last 50K.

I also had the oil light issue which was down to the wrong combination of oilfilter housing gasket/shim/seal, after a bit of messing around I ended up with shim + oilseal and no gasket and have had no oil light problems since. if the oil filter canister is not sealed correctly it causes a drop in pressure which causes the oil light to come on.

Starter motor issue - if its a Valeo strip it and check, my original fell apart at quite a low milage (pretty poor quality) I belive spare parts are available now for them, my solenoid fell apart and then the magnets came unstuck from the main body.

Good Luck