ST1100 Timing Belt and Coolant Hose Change

FWTBT · Dec 22, 2014

I?m looking for advice from the mechanical gods of all things ST1100.:bow1:

I have a 1994 ST1100 with about 81,000 miles. I have put about 25,000 miles on it since I bought it 2 years ago. I love it and am going to keep it until I am too old and decrepit to ride it any longer.

The bike is due for a timing belt change and has a bit of an overheating issue. So I will deal with both at the same time. I will have a shop do the work but I will purchase the parts. In addition to the timing belt I plan on replacing the thermostat, rad cap, all of the hoses and have the system flushed. Maybe it is overkill but I don?t mind spending the money for peace of mind on long trips.

So my questions are:

1. Even though there is nothing wrong with the water pump should I have it changed, do they have a life span?
2. Would I save much on labor cost by replacing everything with the exception of the hoses that involve removing the carbs?
3. How many hours of labor would this involve?

Bush · Dec 22, 2014

First - since you live in Canada, are those really MILES (81,000), or kms?

Changing the water pump *may* be a good idea, but if you are certain there has only been non silicate coolant used over the years and it was changed regularly, I wouldn't go to the added expense, as the seal should last a long time, if well cared for. There is no set life span.

The hoses under the carbs are the ones to be most concerned with and should definitely be done, unless they were done once already. Obviously this will cost you more. Also, you should not only replace those two hoses, but the "elbows" and O-rings that seal them, as they have cracked when being disturbed, or worse, after a job was done and buttoned up.

The flat rate on the timing belt, IIRC from asking a dealer about this many years ago, is around 8 hours. You pay at least one hour for R & R of the plastic in a job like this. With pulling the carbs, I'd estimate another 4 hours easily, considering they will want to do a carb sync once it is all back together.

This is going to cost you an arm and at least part of your leg. I wouldn't be surprised to see about $1,000 in labour, especially since you are not allowing them any profit on the parts by supplying them yourself. No way you can do it yourself? It isn't that hard with some good tools and the Service Manual to guide you.

DeanR · Dec 22, 2014

FWTBT said:
I love it and am going to keep it until I am too old and decrepit to ride it any longer.

Me too...
I recently did my belt at 95k miles. Hemmed and hawed about the water pump and pulleys and since everything looked and felt ok, I passed. Adds a lot of $$, otherwise I would have done it all. Mixed opinions on this topic around here.
Two elbows joints under there along with the hoses.
It's all do-able yourself with all the masterful advice here!

edit ..Looks like Mr Bush and I had the same thoughts at the same time.

ST1100Y · Dec 22, 2014

FWTBT said:
...has a bit of an overheating issue.

Please specify, what does "a bit" stand for in this?

Friend of mine once also had "a bit" of a coolant leak, but using rural roads and m/ways on his commute he didn't notice... until the coolant seeping in destroyed the 40A alternator of his '96 ST1100A...
Alternator was replaced and were leaks fixed at the w/shop, but like 3 weeks later, as aftermath of the above issues with low coolant levels over some period, the LHS head-gasket gave in...

FWTBT · Dec 22, 2014

Bush said:
First - since you live in Canada, are those really MILES (81,000), or kms?

The hoses under the carbs are the ones to be most concerned with and should definitely be done, unless they were done once already. Obviously this will cost you more. Also, you should not only replace those two hoses, but the "elbows" and O-rings that seal them, as they have cracked when being disturbed, or worse, after a job was done and buttoned up.

Thanks for the reply. Those are miles. I usually convert because so many forum members live in the US.

I am having trouble finding the part numbers for the elbows and O-rings on the micro-fiche on "Ron Ayers" or "Honda Parts Nation". Would you by any chance have those.

dwalby · Dec 22, 2014

ST1100Y said:
Please specify, what does "a bit" stand for in this?

+1

It would be wise to figure out why its overheating before considering the PM items you've mentioned.

In my case I had a minor overheating issue that turned out to be the water pump. Since the WP can be easily changed during a timing belt replacement, if you do it now you only have the part cost. The difficult call is the pump is more expensive than you'd expect, but if you do it later you're going to pay a bunch for labor all over again, and the pump won't be any cheaper then either. You're looking at a lot of money to do the stuff you listed because this bike is fairly labor intensive, and with an unknown service history (??) you would always like to replace more rather than less just to remove more unknowns from the list of potential failures.

But if you have engine issues that may be causing your overheating, you need to rule that out first, because if you're paying someone else for labor this bike will quickly get to the point where its not cost effective to repair.

Regarding the questions you asked, ABSOLUTELY replace the hoses under the carbs. Those are a critical failure item that will leave you dead on the side of the road in an instant with no warning. You will also get new carb boots, which is a very good idea if they've never been done before. The big question here is given a 20 year old bike, has that already been done within the last few years before you bought it? If so, no need to do it again this soon, but you have to be 100% sure its actually been done.

dwalby · Dec 22, 2014

FWTBT said:
I am having trouble finding the part numbers for the elbows and O-rings on the micro-fiche on "Ron Ayers" or "Honda Parts Nation". Would you by any chance have those.

look on the fiche page "water pipe" you'll find them there.

FWTBT · Dec 22, 2014

Bush said:
No way you can do it yourself? It isn't that hard with some good tools and the Service Manual to guide you.

I've decided not to do too much work myself with the exception of removing the plastic. The main reason is that I don't have a good place to work on the bike. I have done brake jobs and water pump changes etc. on cars when I was younger but I was very slow at completing repairs and lacked confidence, probably because I was a little too fussy and just not very good at it. It's a little frustrating because I'm not very trust worthy with shops. My father was a mechanic and pulled wrenches his entire life so I am familiar with the business. I'm more concerned with the shop being honest and treating myself and my bike with respect than I am with their hourly rate. I've seen some awful rip offs over the years and find it offensive when a service writer assumes a customer has no knowledge what-so-ever about their vehicle.

FWTBT · Dec 22, 2014

dwalby said:
look on the fiche page "water pipe" you'll find them there.

I feel like a bit of a dummy

: but I just don't see the elbows on the water pipe page of the fiche. Are those listed as
10 19523-MT3-000 Joint, water

DeanR · Dec 22, 2014

FWTBT said:
I feel like a bit of a dummy : but I just don't see the elbows on the water pipe page of the fiche. Are those listed as
10 19523-MT3-000 Joint, water

That's them.

FWTBT · Dec 22, 2014

ST1100Y said:
Please specify, what does "a bit" stand for in this?

Friend of mine once also had "a bit" of a coolant leak, but using rural roads and m/ways on his commute he didn't notice... until the coolant seeping in destroyed the 40A alternator of his '96 ST1100A...
Alternator was replaced and were leaks fixed at the w/shop, but like 3 weeks later, as aftermath of the above issues with low coolant levels over some period, the LHS head-gasket gave in...

The issue seems to be sporadic. Last summer the bike would get hot "sometimes" during stop and go traffic in the city, never on the highway. The fan cuts in and out and seems to be working fine. As far as I can tell the only coolant I find on the ground under the bike is from the overflow from the reserve tank. I don't smell coolant but I have a very poor sense of smell..."broken nose...different story"

: As far as adding coolant goes 114,200 kms - added 300ml; 116,000kms - added 200ml (?); 123,000kms - added 300 ml; 125,00kms - added 200 ml; 131,000kms - need to have a better look at the level but appears to need 200ml because the bike got warm again.

I read through the posts on the ST1100-Riders forum and Mike Martins site regarding coolant issues and suspect it maybe a sticky thermostat, bad radiator cap or a leak between the radiator and the reserve tank or a slow leak somewhere. I haven't pulled the tupperware and removed the rad cap to check the level because I though the problem may be resolved when I overhaul the whole cooling system when I have the timing belt done.

FWTBT · Dec 22, 2014

DeanR said:
That's them.

Thanks for that

. Between STowners, STriders and all the people that take the time get involved in these forums makes it makes them a real treasure chest of information.

dwalby · Dec 22, 2014

FWTBT said:
The issue seems to be sporadic. Last summer the bike would get hot "sometimes" during stop and go traffic in the city, never on the highway. The fan cuts in and out and seems to be working fine. As far as I can tell the only coolant I find on the ground under the bike is from the overflow from the reserve tank. I don't smell coolant but I have a very poor sense of smell..."broken nose...different story": As far as adding coolant goes 114,200 kms - added 300ml; 116,000kms - added 200ml (?); 123,000kms - added 300 ml; 125,00kms - added 200 ml; 131,000kms - need to have a better look at the level but appears to need 200ml because the bike got warm again.

Please clarify a few things.

1. Are you adding coolant to the overflow tank, or directly into the radiator? I think overflow tank, because you later say you haven't removed the rad cap to check the level.

2. Your comment regarding coolant on the ground as a result of overflow from the reserve/overflow/recovery tank suggests it is generally full, or even overfull, but that's inconsistent with your claim to have put in about a full liter of coolant in 10k kms (which is very unusual BTW), presumably into the overflow tank because it was empty.

3. If the fan cuts in and out and the temp gauge stays in the mid-range or just a little higher, that's not overheating, that's normal. If the gauge goes up towards the "H" line, that's overheating. So when you say you have a 'bit' of an overheating issue, are you just referring to the normal climbing of the gauge before the fan brings it back down, or something else?

Bottom line, if you've put a liter of coolant into the system in the distance you've ridden, there is something wrong that needs to be determined. You could have a weak rad cap that's allowing it to boil out, or you could have a leak that you haven't noticed. But I don't think a weak rad cap would run the recovery tank dry, you'd probably just get low level in the rad itself. I've never had the cracked hose to the recovery tank problem myself, but I think the typical symptom would be for the tank to overflow, not go empty (someone else will confirm/deny that hopefully). There could also be a serious engine problem like a cracked cylinder head or failed head gasket that is allowing coolant to escape slowly and is boiling away due to combustion heat. Before investing money in any of the PM you listed, I think this should be priority one to figure out where your coolant is going. Run the bike up to normal operating temp, park it, and let it idle for a few minutes. Look for any signs of coolant leaks, and take a small whiff of the exhaust from behind the bike. If your exhaust has a sweet/fruity smell to it, then your coolant is boiling away inside the cylinders due to a leak of some kind.

Don't want to scare you too much, because it could be something simple causing the issue, but you have to track it down to make sure its not something more serious before investing any money on other maintenance.

Bush · Dec 22, 2014

If you have been adding coolant over the miles, then you have been losing it too! My first guess is the coolant overflow hose at the rad cap has a crack. From what you say about the fan cycling, why are you suspecting overheating? What's important is where does the temp gauge rise to? Anywhere near the 12 or one o'clock position is normal.

FWTBT · Dec 22, 2014

Bush said:
If you have been adding coolant over the miles, then you have been losing it too! My first guess is the coolant overflow hose at the rad cap has a crack. From what you say about the fan cycling, why are you suspecting overheating? What's important is where does the temp gauge rise to? Anywhere near the 12 or one o'clock position is normal.

I agree with you regarding the overflow hose. I noticed there is no clamp on that hose near the rad cap. I've had the bike long enough to be familiar with where the temp gauge sits while the fan cycles at normal temps. I've idled the bike in hot weather and watched the gauge move as the fan kicks in and out. The gauge is definitely going much higher than it use to while the fan is cycling. I recently had the bike out on a cool day, it wouldn't cool down after I parked it and the fan was running. I shut the bike down and it puked coolant out of the overflow from the reserve tank. As I mentioned before the problem was sporadic last summer. I could take the bike out again but I hate to keep heating the engine up for fear of causing other damage like head gaskets? I thought that by overhauling the entire system while doing the timing belt should cover the problem? I also thought that because of the age and mileage on the bike and the long trips I have planned in the future it may be worth while just to spend the money and have the work done.

kiltman · Dec 22, 2014

Last Christmas I had the timing belt replaced by my local shop. (I removed all the Tupperware )and the labour was $250. The belt was around $80. They also flushed the cooling system for me as well. I had discussed with the mechanic if I should change the pump as well, he was of the opinion if it ain't broke don't fix it. ( my bike is a 1990). My bike doesn't appear to have any cooling issues at the moment.
if the coolent was leaking into the cylinders it may appear as white pellets or cloudy swirls in your engine oil. Have a look when you do an oil change.
I agree with others, try and track down the source of your leak.
As an aside, when I got my timing belt done I also had the shop install my cruise control cable to the carb linkage. For that process they had to remove the carbs, they found only one of my intake hoses to be cracked and they replaced that. What I neglected to get done at the time was a carb sync, that was a "duh" moment on my part.
all the best in getting your bike serviced

FWTBT · Dec 22, 2014

dwalby said:
Please clarify a few things.

1. Are you adding coolant to the overflow tank, or directly into the radiator? I think overflow tank, because you later say you haven't removed the rad cap to check the level.

2. Your comment regarding coolant on the ground as a result of overflow from the reserve/overflow/recovery tank suggests it is generally full, or even overfull, but that's inconsistent with your claim to have put in about a full liter of coolant in 10k kms (which is very unusual BTW), presumably into the overflow tank because it was empty.

3. If the fan cuts in and out and the temp gauge stays in the mid-range or just a little higher, that's not overheating, that's normal. If the gauge goes up towards the "H" line, that's overheating. So when you say you have a 'bit' of an overheating issue, are you just referring to the normal climbing of the gauge before the fan brings it back down, or something else?

Bottom line, if you've put a liter of coolant into the system in the distance you've ridden, there is something wrong that needs to be determined. You could have a weak rad cap that's allowing it to boil out, or you could have a leak that you haven't noticed. But I don't think a weak rad cap would run the recovery tank dry, you'd probably just get low level in the rad itself. I've never had the cracked hose to the recovery tank problem myself, but I think the typical symptom would be for the tank to overflow, not go empty (someone else will confirm/deny that hopefully). There could also be a serious engine problem like a cracked cylinder head or failed head gasket that is allowing coolant to escape slowly and is boiling away due to combustion heat. Before investing money in any of the PM you listed, I think this should be priority one to figure out where your coolant is going. Run the bike up to normal operating temp, park it, and let it idle for a few minutes. Look for any signs of coolant leaks, and take a small whiff of the exhaust from behind the bike. If your exhaust has a sweet/fruity smell to it, then your coolant is boiling away inside the cylinders due to a leak of some kind.

Don't want to scare you too much, because it could be something simple causing the issue, but you have to track it down to make sure its not something more serious before investing any money on other maintenance.

Thanks for your reply. Sorry if I am confusing things, sometimes I confuse myself.

: When I said "bit" that may have been a "bit" misleading.

I am adding coolant to the reserve tank and only when the level goes below the low line when the bike is cold. I suppose it is possible that I am overfilling the system but I am sure the bike is overheating as I am quite familiar with where the needle sits on the temperature gauge. I haven't noticed a difference in the exhaust smell and haven't found any sign of coolant leaks other than out of the reserve tank. However I haven't stripped the bike down to have a better look.

SMSW · Dec 22, 2014

FWTBT said:
Thanks for your reply. Sorry if I am confusing things, sometimes I confuse myself. : When I said "bit" that may have been a "bit" misleading.

I am adding coolant to the reserve tank and only when the level goes below the low line when the bike is cold. I suppose it is possible that I am overfilling the system but I am sure the bike is overheating as I am quite familiar with where the needle sits on the temperature gauge. I haven't noticed a difference in the exhaust smell and haven't found any sign of coolant leaks other than out of the reserve tank. However I haven't stripped the bike down to have a better look.

I've not had much experience with liquid cooled bikes, but I've been playing with cars for most of my adult life. Coolant leaks, especially on hot surfaces (like a radiator) leave tracks. The liquid boils away and the solids leave telltale marks or deposits. You have not mentioned seeing any of these.

You stated that you have not noticed any difference in the exhaust smell. And you said that due to a broken nose, you cannot smell. Have a friend or wife sniff the exhaust for the distinctive antifreeze smell. Better yet, see if there is an experienced ST'er in your neck of the woods and connect up with that rider.

I tend to agree w you on paying for maintenance - as long as you have a trusted mechanic/shop. But, and here is the big but. I bought this bike promising myself I would ride and not work on it. Been there, done that. Last winter I took all the tupperware off, did a bunch of stuff and now I'm doing it again, mostly minor maintenance issues and a lot of accessorizing. My point is, I am enjoying it, I get help here, I use the shop manual, and I'm saving money (well not really - I just put it right back into accessories). You can probably do more than you think - but this is a personal choice. Up north where you are, if you have a place to work on the bike, you have all winter to do it.

Good luck!

kiltman · Dec 22, 2014

You might have an airlock in the system, you may have to burb it.

i think you can have the the system pressure tested to determine if you have leaks.
just throwing out some random thoughts

Brant · Dec 22, 2014

FWTBT said:
Thanks for your reply. Sorry if I am confusing things, sometimes I confuse myself. : When I said "bit" that may have been a "bit" misleading.

I am adding coolant to the reserve tank and only when the level goes below the low line when the bike is cold. I suppose it is possible that I am overfilling the system but I am sure the bike is overheating as I am quite familiar with where the needle sits on the temperature gauge. I haven't noticed a difference in the exhaust smell and haven't found any sign of coolant leaks other than out of the reserve tank. However I haven't stripped the bike down to have a better look.

Have a closer look at that rad. cap for a start....if you have no coolant drippin' off in the centerstand area

. The outer seal of cap can have horizontal breaks across rubber, losing seal. Definitely losing coolant, as there should'nt ever have to be any added....unless an external leak exist.
My STeed did the similar for a couple riding seasons, which included a couple LD rides west to Caly and back. Replaced rad. cap, and that sealed things up good ,pressurizing system at operating temp...........until coolant elbows/o-rings decided they wern't gonna hold with the system working correctly...........which meant for the minimal cost, replacement of carb boots were a no-brainer at the same time, as originals will NOT re-seal totallly

.