belt with almost 100k started showing wear

[mickskelly]

Hi. Just showing a few pics of the belt I replaced which may be useful to people here. It's an ex police bike with 96k miles. I don't have her long, put a couple of hundred miles on her and then replaced the belt. Interestingly the old belt is showing a little wear. Light chipping on the edges and what could be the very start of some cracks starting to form. The change was perfect timing I think (pun completely intended). The belt was slight floppier then the new one (up and down, no side to side movement). But still felt strong. The photos show the worst bits.

 

[STArnie13]

What year is the bike?

 

[Illinois]

Starting to show wear after a mere 96k, so much for Honda quality. Thanks for posting the pic.

 

[BakerBoy]

Some quick calcs... assuming ~45mph and ~3000rpm average, the engine has turned over ~380 million times. Shame a belt can't last more than that! LOL

 

[STranger]

I just did mine at 73000 miles due to the water hose busting under the carbs........mine was in much better shape

 

[vinny]

Looks like it might have been rubbing on something... did you check the water pump pulley and the tensioner for play. All the other belts I've seen have no edge wear and look like new.

 

[Skunkape]

Interestingly the old belt is showing a little wear.

That's not "showing a little wear" It's worn out. Don't just focus on miles when considering timing belt change. Age kills them too.

 

[Ron]

That isn't that many miles. Do the police let the bikes idle like they do the cars (in the US)?

 

[sfalexi]

That isn't that many miles. Do the police let the bikes idle like they do the cars (in the US)?

not that I've seen. Maybe a little bit to get off an talk to someone, but not like they do going into a food joint or anything like that.

Cool though. I'm thoroughly excited to see these bikes going up there in mileage. Gives me hope for many years, and a little sadness cause it'll be many years before I can convince my wife it's time to upgrade. lol.

Alexi

 

[Red Alert]

Is there a "drop dead" date to change the belt? Recommended max mileage for a routine belt change? I can see that a 100K is too long. Red

 

[dwalby]

Is there a "drop dead" date to change the belt? Recommended max mileage for a routine belt change? I can see that a 100K is too long. Red

Service manual says 90K miles, no mention of age. At 16 years and 96,600 miles mine looked almost like brand new, and I have read a lot of similar comments here. Also, the pulleys in there are extremely high quality, they seem like they'd last forever, but I changed them anyway because I bought the parts before doing the dis-assembly and figured they'd be due for replacement anyway.

Once you get in there and touch the parts you might think that 100k is not really too long, but until you do, you're always going to be wondering. Also, considering the consequences of any failure in the system (pulleys, belt, water pump) its probably a good idea when you do change the belt to bite the bullet and change all the moving parts (water pump + pulleys is close to $400 in parts). Then you can walk away from it for another 100k miles and not give it a second thought.

 

[George]

I agree with Dwalby...

Honda recommends a visual inspection at 60,000 and change at 90,000. I say do a visual inspection at 90 and if it looks okay, change it at 110. I expect a visual inspection at 90 would'a showed the problems with that belt.

I've said for a long time I suspect most belt failures are predicated on a failing bearing in one the pulleys or gears. If they all check out upon the eventual belt replacement, they should be good to near 200K. When I changed STick's belt the first time (at 83K, in 96) it was because I assumed the 90K recommendation was legit and I was leaving on a long trip. The original belt even looked new, printing was 90% as bright as the replacement. She got her third before 200,000. It's a used belt out of a wrecked 91 which had ~30K on it. It now has closer to 60K.

LipSTick got her second at 110K, the new one is a Gates brand sourced from Amazon.com. Saved about $30 compared to OEM and many of suspect Gates makes the OEM belt anyway. The belt is unique and even Gates lists no other use for it.

Anyhoo, good for the OP for catching this before a catastrophic failure. Hope your bearings are up to snuff but I think I'd be double checking.

 

[nhdiesel]

I've done 100+ timing belt replacements on cages and got to several too late. I've pulled out broken belts that looked like new everywhere except where they broke. I've also replaced lots that looked new, because they were at the change interval. My theory is that if you gamble wrong you lose an engine so play it safe. If you are nearing the service mileage, or if its more than 10 years old, I would replace it.

For what it's worth below is a one year old belt from an ST-O member's cage. I found two dry/rough idler bearings and a failing tensioner. The shop took the cheap way out and only changed one belt (this vehicle uses two belts- one for cams and one for balance shaft) and one idler (the easy one to get to). It nearly cost him an engine. I replaced both belts, all three pulleys, and the tensioner to be safe. If the last shop had done that, it would have saved a bunch of money in the long run.

Sent from my XT881 using Tapatalk 2

 

[George]

Gotta give kudos to Diesel, he's changed a lot more of'em than I have and has seen a lot more failures. Honda makes their recommendations for a reason.

 

[ST1100Y]

My theory is that if you gamble wrong you lose an engine so play it safe. If you are nearing the service mileage, or if its more than 10 years old, I would replace it.

I whole-heartedly agree to this, yet made my rule of procedure many years ago (stupid workshop ignored this issue on one of our favorite service-vans...) Besides this: with the effort required for digging into there to only 'inspect' the ST1100 timing belt properly (which would involve removing it to give it a full visual and have all pulleys/bearings unstressed to check their condition...), I can already replace the thing plus the two pulleys involved as well anyway... it'll take merely 30 minutes longer... the piece of mind gained is simply priceless... so I would never go 'cheap' by stretching or ignoring this replacement interval; if that thing gives in, the engine will destroy itself violently, period...

 

[nhdiesel]

Every original ST1100 belt is already well past 10 years old. Regardless of miles, if I were inside the timing cover already, I would be replacing the belt and at least checking the pulleys. I would also replace the water pump if it wasn't already done. We aren't talking about an alternator failing if it gives out...we are talking bent valves & damaged pistons. Considering how many people replace tires when they start to get aged, and you can SEE those easily to inspect them, I would think the belt would be a high priority.

 

[dwalby]

Every original ST1100 belt is already well past 10 years old. Regardless of miles, if I were inside the timing cover already, I would be replacing the belt and at least checking the pulleys. I would also replace the water pump if it wasn't already done. We aren't talking about an alternator failing if it gives out...we are talking bent valves & damaged pistons. Considering how many people replace tires when they start to get aged, and you can SEE those easily to inspect them, I would think the belt would be a high priority.

In theory I agree with you 110%, but the reality is when you get in there and see the quality and condition of the parts, you realize they are capable of going many many years and miles. Compared to stuff I've seen in cars they're worlds apart in terms of quality. So I'm agreeing with you, but I'm saying its not right to panic just because your belt is over 10 years old either. The reality of this maintenance is you can't inspect the belt completely without doing as much work as is required to replace it, so the inspection makes no sense at all, other than looking through the small opening in the timing cover when doing valve adjusts. There seems to be an abundance of evidence that 15 year old belts with 90k miles still look like new. Not saying they didn't need replacement, just saying they aren't likely to fail at 91k if you don't jump on it right away.

 

[nhdiesel]

Agreed...that is why i said IF I were already inside the timing cover, replace it rather than looking at it and guessing. I would still make darn sure I never ran a belt to 100k though. I can tell you lots of stories of people driving cages with 200k on them with the original belts. I can tell you just as many about belts failing at 70-100k miles. Honda has a bit higher limit than the 60k that is typical of most cage belt limits, but I still wouldn't take the chance. If I had the timing cover off at 70k I would do the belt while there. If I had 90k+ miles, I would make it a point to do the belt the next chance you have to park the bike for service.

 

[ST1100Y]

...we are talking bent valves & damaged pistons.

In its 'best' case, likely it'll go way beyond that... cracked heads, valve/seat debris causing pitted and scratched cylinder honing, shattered piston crowns, connecting rods slammed bend thus low end bearings damaged thus possible bend/twisted crank... 'repair' would require re-centering of crank case bearing bores, measuring/checking the crank (replace if damaged), polishing its bearing seats (oversized bearings), new connecting rods + bearings, if only minor damage re-honing of cylinders, otherwise new blocks, new (oversized) pistons + pins, new rings, new heads with new valves, new cams, etc, etc... who want's to go through all that, compared to the price for a new t/belt plus pulleys (and a new water pump to cover all the bases...)
and IMHO you cannot determine it only by age or mileage numbers, rather by climate and usage conditions... parts inside an engine used for urban commuting with lots of idling/stop'n'go times will suffer/age/deteriorate way faster then those inside one that only sees free motorways in rather mild climate and much cooling airflow. Also many 'cold starts' (i.e. winter usage) will increase wear and aging of parts...

 

[George]

Considering how many people replace tires when they start to get aged

I don't. (I've mentioned the story before about passing on a well aged and stored CL350 Honda with the original tires. The guy I gave it to got it running and took it to track days. On the original (dry, cracked Dual sport) tires and had a ball with it. Never a problem. )

Anyhoo, everyone knows I'm lackadaisical when about maintenance, so if yur looking for advice you'd be well advised (from me) to follow 'Diesel's advice.