Timing belt inspection tips?

[SpoogyWoogy]

Hi again all,

I recently purchased a 1991 st1100 with 58k miles on it.
I don’t know of it’s service history so I’m going to be changing the timing belt.
(It should arrive in the next week or so but I’m not sure).

Google tells me it’s a ticking time bomb but a lot of forum users seem to ride on original belts for well over 100k miles.

I’d like to be able to ride the bike until the timing belt arrives but I’m not sure if that’s a good idea.

Is there a way to easily inspect the timing belt for any wear (without pulling off the radiator) to see if it’s good for maybe 100 miles or so of chill riding until my timing belt arrives?

Just don’t wanna blow up my engine and I wasn’t able to find a thread on this topic specifically.

Thank you!

 

[Uncle Phil]

Ticking time bomb - that's a joke.
I don't change mine until 100,000 miles regardless of age (BTDT 3 times).
The ST1100 timing belt is thankfully well over-engineered.

 

[SpoogyWoogy]

Ticking time bomb - that's a joke.
I don't change mine until 100,000 miles regardless of age (BTDT 3 times).
The ST1100 timing belt is thankfully well over-engineered.

Phew!
Good to know. I’ll be changing it in the coming weeks for peace of mind but until then I’ll keep enjoying the bike as is!

 

[ST1100Y]

I don’t know of it’s service history so I’m going to be changing the timing belt.

For peace of mind, I'd agree wholeheartedly...
plus:
- idler pulley
- spanner pulley
- w/pump
at least check them... (those on my '00 ST with ~150,000km turned out already quite worn and noisy...)

 

[SpoogyWoogy]

For peace of mind, I'd agree wholeheartedly...
plus:
- idler pulley
- spanner pulley
- w/pump
at least check them... (those on my '00 ST with ~150,000km turned out already quite worn and noisy...)

I haven’t ordered the pulleys or pump.
Do those give out before the belt? If so I might order them now.

Edit: just to check how many of each would I need to order? Sorry, my service manual hasn’t arrived yet so I don’t have any access to diagrams or parts lists on hand.

 

[dwalby]

pulleys are a good idea to change, but they are expensive.

tensioner pulley part number is 14510-MT3-003
idler pulley part number is 14560-MT3-003

water pump is crazy expensive, but I'm not sure if its even available from Honda any longer, part number 19200-MAJ-G20

 

[SpoogyWoogy]

For peace of mind, I'd agree wholeheartedly...
plus:
- idler pulley
- spanner pulley
- w/pump
at least check them... (those on my '00 ST with ~150,000km turned out already quite worn and noisy...)

Just had a look. Yeah… a bit pricey.
I guess I’ll just get the idler and tensioner .
If they aren’t prone to failing and eating up my new (also expensive) timing belt I’d rather not buy them but for peace of mind I suppose…

 

[Andrew Shadow]

Expensive but possibly a wise investment. Most ST1100 engine damage related to timing belt failures that I have ever read about were due to the water pump or pulleys failing. This caused the timing belt to fail, jump, or break, resulting in engine damage but the initial failure was never the timing belt. I have never read of an ST1100 timing belt failure that was due specifically to the timing belt. Most ST1100 timing belts still look new at 100,000 miles.

 

[SpoogyWoogy]

Expensive but possibly a wise investment. Most ST1100 engine damage related to timing belt failures that I have ever read about were due to the water pump or pulleys failing. This caused the timing belt to fail, jump, or break, resulting in engine damage but the initial failure was never the timing belt. I have never read of an ST1100 timing belt failure that was due specifically to the timing belt. Most ST1100 timing belts still look new at 100,000 miles.

Good to know!
I’ll be replacing the pulleys then but the water pump is like 45k yen (a lot for someone on a Japanese salary) so I’ll stick with an inspection for the time being.

Are there any warning signs for a bad pump? Noises or the like I should be looking (or listening) out for?

Thanks!

 

[Andrew Shadow]

Same inspections that apply to any shaft driven appliance that runs through bushings or bearings. Excessive play both vertically and laterally. Smoothness- there should be no rough spots, notchiness, no points at which it is harder to rotate, no excessive noise that sounds like gravel rolling around. No coolant leak. If your inspection determines that everything is in good shape you have determined that they are in good shape at that moment. Will they still be in that condition in another 30,000 miles? Impossible to know, which is why some people opt to change everything when they change the timing belt.

 

[SpoogyWoogy]

Fair enough. If I could afford to I would swap all the parts out but I simply can’t do so at the moment.

I suppose I can simply reinspect next time I do a coolant flush.

I was wondering if there were any noises specific to a failing water pump (squealing, clunking, etc).

Thanks!

 

[Uncle Phil]

I had a water pump fail at 130,000 Miles (grenaded engine) and one leak at 140,000 miles.
So I am in the camp now of changing it when you change the timing belt and pulleys at 100,000 miles.

 

[SpoogyWoogy]

Totally fair.
I’ll have think about whether I can spare the cash at the moment.
I’m already quite over budget with the bike but I’ll see if I can handle it.
Thanks.

 

[dwalby]

I was wondering if there were any noises specific to a failing water pump (squealing, clunking, etc).

In my case, yes, the bearing started to squeak so I replaced it. I wouldn't assume that all failures give warning though.

curious if Uncle Phil heard anything from his before they failed, he didn't say in his reply.

 

[SpoogyWoogy]

Good to know! I’ll keep an ear out for that. I’ll also be careful about the water pump as well.

 

[ST1100Y]

Edit: just to check how many of each would I need to order? Sorry, my service manual hasn’t arrived yet so I don’t have any access to diagrams or parts lists on hand.

Fortunately are there sites like Classic Motorcycle Spares featuring a library of full fiche to locate P/N:

Honda ST1100 PANEUROPEAN 1991 (M) EUROPEAN DIRECT SALES / KPH parts lists and schematics

✓ Honda ST1100 PANEUROPEAN 1991 (M) EUROPEAN DIRECT SALES / KPH parts lists and schematics ✓ Easy repairs with Honda diagrams ✓ Free access!

www.cmsnl.com

As for ordering, in your neck of the woods this site might be interesting:

Motorrad-Teile aus Japan - Webike

Webike Japan! Das größte Lager von Motorradteile & Motorradzubehör online. Wir bieten internationalen Versand.

www.webike.co.at

 

[Uncle Phil]

In my case, yes, the bearing started to squeak so I replaced it. I wouldn't assume that all failures give warning though.

curious if Uncle Phil heard anything from his before they failed, he didn't say in his reply.

On the first one that grenaded the engine I heard what I thought was gravel in the fendaextenda but turns out it was not.
The water pump and pulleys were 'supposedly' inspected by the Honda shop that did the timing belt change and other service work at 100,000 miles. Though the valves were bent, the timing belt did not break.
The second one, I just notice a line of antifreeze down the left side of the engine.