I have a 94 st1100 and it snapped the timing belt , whats the chances i didnt bend any valves ? and if i replace the engine do i need a special tool to get it out as i know some st13s need a tool to get the engine out
snapped timing belt
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Andrew Shadow
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Chances are slim, especially if you were at anything above idle.
As far as tooling goes, @Uncle Phil can answer all of your questions as he just did an ST1100 engine swap.
Have a look at his thread until he weighs in-
Anybody Here Ever Replaced A ST1100 Engine?
As far as tooling goes, @Uncle Phil can answer all of your questions as he just did an ST1100 engine swap.
Have a look at his thread until he weighs in-
Anybody Here Ever Replaced A ST1100 Engine?
Welcome to the forum.
Low, unfortunately; the ST is an interference engine.
It's a rare occurrence. How many miles on this belt?
Low, unfortunately; the ST is an interference engine.
It's a rare occurrence. How many miles on this belt?
Shrek, firstly bad luck.
Secondly, welcome to the forum from Northumberland.
Thirdly, you're probably in luck, @Uncle Phil here has just done this and Millyard has just posted videos on YouTube on this very subject.
Your valves are probably scrap.
Good luck.
Upt'North.
Uncle Phil
Site Supporter
No special tools to get the engine out but it is a lot of work.
Getting it out is a lot easier than getting it in (had to hoist the entire bike up in the air and roll the engine under the frame then jack the engine up and lower the frame - a 2 man job unless Mr. Millyard has a better method which I am waiting to see).
Are you sure the belt broke?
If it did and the crank continued to spin, your valves are more than likely toast as the pistons would continue to move up and down and the valves would be out of position.
The only way I know you could tell if the valves are bent is to pull the heads (quite a bit of work) unless someone else has better idea.
Very unusual for a ST1100 timing belt to break - usually it's the water pump or the idler pulley that goes south and the engine jumps time.
Getting it out is a lot easier than getting it in (had to hoist the entire bike up in the air and roll the engine under the frame then jack the engine up and lower the frame - a 2 man job unless Mr. Millyard has a better method which I am waiting to see).
Are you sure the belt broke?
If it did and the crank continued to spin, your valves are more than likely toast as the pistons would continue to move up and down and the valves would be out of position.
The only way I know you could tell if the valves are bent is to pull the heads (quite a bit of work) unless someone else has better idea.
Very unusual for a ST1100 timing belt to break - usually it's the water pump or the idler pulley that goes south and the engine jumps time.
Andrew Shadow
Site Supporter
Pull the valve covers and rotate the cams, or pull the cams. With the cam lobe in the closed valve position or with the cams removed, bent valves won't close and seal. You can tell by the height of the valve stem or by pumping compressed air in to the spark plug hole to see if they seal when they should.
Aka. Check the compression. Bent valves will not compression
Spit balling an idea here.. Could you use an inspection camera in a spark plug hole to see if the valves moved / seated instead of pulling a cover etc?
Bmacleod
Site Supporter
OP, why not put in a new timing belt and do a compression test. If the motor is still good, then you're golden. If the motor is toast and needs to be replaced, you have a new timing belt for the replacement motor, which would be very advisable anyway. I would be very surprised if you didn't bend some valves, but, it never hurts the check first. It would save you a lot of time if you got lucky and didn't bend any.
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Welcome Shrek
Hoping Fiona is not as upset as you are.
Depending on how much this is your pride and joy, I would start with just the heads. It may be only 10-20% of the valves that need servicing.
Worst case, pull the engine, heads are already off.
Cheers
Hoping Fiona is not as upset as you are.
Depending on how much this is your pride and joy, I would start with just the heads. It may be only 10-20% of the valves that need servicing.
Worst case, pull the engine, heads are already off.
Cheers
Uncle Phil
Site Supporter
Probably tough to check compression if the timing belt is broken as turning over the engine would not 'move' the valves.Aka. Check the compression. Bent valves will not compression
With mine, the belt was not broken and when you spun the engine it was easy to listen and know there was no compression as it spun 'freely'.
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How bout just pulling the cams and trying a compression tester.Probably tough to check compression if the timing belt is broken as turning over the engine would not 'move' the valves.
With mine, the belt was not broken and when you spun the engine it was easy to listen and know there was no compression as it spun 'freely'.
Wouldn't one of the belt pulley covers at the top of the engine be one way?
based on the few reported cases of timing belt incidents in the ST1100 world, the belt is usually not the primary cause of the problem, its collateral damage from something else, like a seized water pump.
Given the interference design of the engine, its very unlikely the valves aren't bent. So, if you can find a decent replacement engine, that's probably the most practical way to go.
Verify the valves are bent first with a compression check as mentioned by others, but I'd be surprised if they're not bent.
Given the interference design of the engine, its very unlikely the valves aren't bent. So, if you can find a decent replacement engine, that's probably the most practical way to go.
Verify the valves are bent first with a compression check as mentioned by others, but I'd be surprised if they're not bent.
I checked ebay yesterday. Saw there are wrecking yards in Ohio and Wisconsin with early ST1100 engines, complete with alternator assemblies. 50,000 miles and up. One shop has posted compression results. That's always a fallback....lots of work involved. If you go the engine replacement route, check the alternator on the 'new' engine. A good indication that it is suspicious is burned wiring/connector or an oil leak where the wiring exits the back side of the unit. If you go that route, consider a newer engine with a conventional alternator design.
My pre-ST bikes were Honda GL1000's. My favorite broke the left side timing belt...no noises, the engine just quit. The intake valves were bent but this was a really simple repair on that bike.
That belt failure experience lead me to replace the belt on my 1991 ST1100 right after I bought it eight years back. Had just 14000+ miles on it but was 24 years old at that point.
As others have mentioned, your broken belt was likely a response to a water pump or pulley failure. Plus side is that there is lots of good help available on this site.
My pre-ST bikes were Honda GL1000's. My favorite broke the left side timing belt...no noises, the engine just quit. The intake valves were bent but this was a really simple repair on that bike.
That belt failure experience lead me to replace the belt on my 1991 ST1100 right after I bought it eight years back. Had just 14000+ miles on it but was 24 years old at that point.
As others have mentioned, your broken belt was likely a response to a water pump or pulley failure. Plus side is that there is lots of good help available on this site.
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May not be what you want to hear - - but if valves are toast,why not buy another similar bike?Lower mileage,change all belts,Less labour.Use your farkles.Keep old bike for those unobtainium Tupperware bits,etc?
Welcome to the forum from Cornwall UK. I hope you manage to sort your problems out.
Had that on another bike, replaced the timing chain and checked compression. Came out fine, I had a belt snap on a Ford Courier and that took not only the valves out but the entire head was damaged.
I may catch some flak for this but I would say that if the belt on my ST went and the valves and/or head were to be damaged I would get another bike as it would not be economical to do the repair.