R1100GS Big Ends are gone.....

Welshman

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So I have an R1100GS in my garage (it's not mine), it was running, but had apparently been rumbling so the owner had the Alternator bearings changed:blast, he took it out and it lost power and a nasty noise.

I gave it the once over and yes VERY NASTY noise, I assumed it had dropped a valve, but removing the plug no plug damage so I popped the head off.



Valves all good, bores good, camchain tensioners good.



So pulled the barrel OOOHHHH Vark the Big end has a few milimetres of play in it, the clanking noise must have been the piston hitting the head, check the periphery of the piston!




What's the concensus with this much wear the crank will also be toast??:eek Is it worth a rebuild or look for a short motor? :beer:
 
Littledumptruck said:
Purely out of interest, what kind of mileage has it done?
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Meant to have a look but forgot to, I would not be too trusting of it anyway, the bike clearly has a history, the rear bevel box is a 31/11 so off an 1150, the beak is 1150 so who knows if clocks are original. :D
 
Whenever anyone post pictures of engine internals I have no idea what I’m looking at – whilst I understand the internals, no reference point means that I don’t know what bad looks like. Interesting all the same though.

However, the same thing happened to my 1150 last year – worn big ends resulting in a knackered crank and a very nasty noise. I looked at all options, even had a spreadsheet on the go – sell the bike as is, break the bike for spares, new crank or new/used short block. The most cost effective option was a low mileage used short block and then a complete rebuild around this. I ended up paying a small fortune for the labour charges but it looks like you could do it all yourself. Mileage on my bike was around 120,000.

If you do go down the rebuild route, please post a rebuild thread. Good luck.
 
wouldn't take more than a few minutes work to whip the rods off for a visual look at the journals, post up pictures if you do....
 
Remove the conrods and check if the crank journals are scored or scuffed.

If it's isn't scored but just blackened, then the cost of a set of big ends and simplicity of replacing them compared to the other options makes it worth trying.
 
Steptoe said:
Remove the conrods and check if the crank journals are scored or scuffed.

If it's isn't scored but just blackened, then the cost of a set of big ends and simplicity of replacing them compared to the other options makes it worth trying.
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OK will look, but thought that since they have enough play to smack the head it would be a done deal:D
 
Beebop said:
Thats not a lot of mileage , was the bike oil starved ?, I thought maybe left running on the
side stand, but its the left and not right pot.
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Hello Beebop, No idea, no history on it, maybe on its side after being dropped.....
 
Welshman said:
OK will look, but thought that since they have enough play to smack the head it would be a done deal:D
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I can't see any marks anywhere on the piston crown to suggest it's hit the valves/head ?.
 
Steptoe said:
I can't see any marks anywhere on the piston crown to suggest it's hit the valves/head ?.
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How about the carbon free ring on the top of the piston around the edge and the corresponding carbon free area on the head?
 
Steptoe said:
I can't see any marks anywhere on the piston crown to suggest it's hit the valves/head ?.
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LHS Head




LHS PISTON



RHS HEAD




RHS PISTON




Iassumed the lack of carbon indicated it was slapping? Someone has used epoxy putty on the gearbox to engine joint?
 
Soooo, shall we continue :D

Locking pin inserted to lock the motor at TDC or it turns while you play...



Pistons off, removing gudgeon pin circlips isn't picture worthy:beer: but you can see not too much space for my sausage fingers:D



And voila out the cap comes:D



Ummmm where is the bearing cap:eek




Just like new :blast





I think I can advise the owner, he has a slight problem, for interest the RHS is 100% but looks like its burning oil that side as there is carbon at the top of the bore :rolleyes:
 
I reckon got there at the right time since as they say:

"Failure of a connecting rod is one of the most common causes of catastrophic engine failure." :D

Way too little mileage for R11xx engine to have it considering mine is 260K and I've seen more than 700Kkm R1100 engine still in stock form.

Judging from the outer rim of the piston and head it did touched the end, but just barely. Although it's not some modern ultra-high-compression engine still there must be very little tolerance left considering the controd bearing wear probably just gives few additional micrometers and the piston already touches the cylinder head because of this. Also check if the conrods themselves haven't been bent or twisted.

In any case it already smells that it's cheaper/easier to get a new s/h short engine bloc, unless you're curious and want to do everything yourself. Good luck!
 
Tsiklonaut said:
I reckon got there at the right time since as they say:

"Failure of a connecting rod is one of the most common causes of catastrophic engine failure." :D

Way too little mileage for R11xx engine to have it considering mine is 260K and I've seen more than 700Kkm R1100 engine still in stock form.

Judging from the outer rim of the piston and head it did touched the end, but just barely. Although it's not some modern ultra-high-compression engine still there must be very little tolerance left considering the controd bearing wear probably just gives few additional micrometers and the piston already touches the cylinder head because of this. Also check if the conrods themselves haven't been bent or twisted.

In any case it already smells that it's cheaper/easier to get a new s/h short engine bloc, unless you're curious and want to do everything yourself. Good luck!
Click to expand...

To me although its not my bike, I would say goodbye, split it out and find a good one, this bike has no history and nothing looks good, the owner isnt contactable, on a months trip in Namibia etc, loverly pace as you know
 
There was evidence that the Air Box had been repaired at some stage, so my guess is that a LOT of sand and dust got in resulting in the premature failure..

Anyway, owner got a great deal on a used 1100 motor and the transplant was done... she lives again...:D
 
Glad your sorted, it's unlikely though a lack of air filtration would cause your big-ends to fail, dust & debris would not get past the rings, usual result is increased bore wear and valve guide wear.
 
Nippy Normans supply Touratech, Wunderlich, Desert Fox and many other makes of accessories.
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