Anybody Here Ever Replaced A ST1100 Engine?

Uncle Phil said:
A little 'post mortem' on the old engine -
The timing belt shows a groove - almost a tear - in the middle of it which tells me it did a major slip.
And the water pump is close to being frozen - very hard to turn with your hand.
So my original prognosis on the side of the road was correct - the water pump roached, the belt slipped, she jumped time, and the valves were toast.
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Glad you got your ST1100 back on the road again. Takes some real dedication to keep these old bikes going. Also glad your autopsy showed belt did not break as you suspected all along. So now at 82K miles on mine I can sleep good knowing I got a long while before I have to check it.:dr11:
 
Yeah, it was the classic water pump failure.
IMHO, that is the only possible 'design' weakness in the ST1100 - if the water pump fails, it's gonna get ugly! :biggrin:
This one died at 139,900+ miles.
Yet I have another one with 172,000+ miles and the original water pump is still going strong.
 
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Uncle Phil said:
IMHO, that is the only possible 'design' weakness in the ST1100 - if the water pump fails, it's gonna get ugly! :biggrin:
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yeah, it hurts to pay almost $300.00 for the part alone and replace it if it hasn't failed, but as these bikes age even more and parts get harder to find it makes a lot of sense to be proactive and change it out early.
 
Thanks for the update, valuable info. I just did the timing belt and replaced the tensioner pulleys as well. I had them check my pump and it was still good. My engine has 110k kms (70 k miles. ) I still have a water pump from my 97and it was changed out at 77k miles and it’s in great shape but I bought a kit to rebuild it if necessary in the future.
The 1990 I owned has over 200k kms on it and it’s still going strong with original pump and tensioners.
 
Found this on Youtube, just uploaded this week.
This is part 1 engine removal and dismantle.
He had a knock on a new to him St1100, and needed to find the source of the problem.

 
Uncle Phil said:
I am really interested in seeing how he reinstalls the engine.
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Seems I'm among the few chosen... ;)
Damaging my '92 ST some-when in '96 I'd to deal with a bend frame tube, hence replaced the frame too...
In this I found it much easier to simply jack the engine/oil pan firmly on wooden blocks, pull the (in my case damaged) frame off it to slip the new one on again...
The engine weights over 90kg/200lbs... the frame: a lot less... :cool:
So fairings off, tank out (hopefully nearly empty), carbs out, forks off, swing-arm out (which is essential anyway, as fumbling engine/output shaft back into the tiny U-joint stub is nearly impossible, the other way around, pushing the prop-shaft on the output stub OTOH is pretty easy...)
 
I just wonder if he has any neat 'trick' for installation.
Basically I did the same on my install but didn't remove the forks or the top box.
Just created a double chain cradle for the frame and connected it to a hoist on my workshop 'skyhook'.
Then with the motor on a motor/ATV hoist, rolled it under the frame and raised/lowered the two objects until things lined up.
Maybe he has 'different' way on reinstallation - I reckon we'll see! :biggrin:
 
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