What happens if the timing belt brakes?

[raggun]

Hello everybody

I will be getting my 1981 standard tomorrow. It has 33.000 miles on the clock.

The replacement history on the timing belts is unclear so replacement is a must.

It is however clear that a few days will pass utill i can get it to the garage for replacement and I am clearly interested in riding the bike.

So my question is:

What will happen to the motor if the timing belt snaps. Is the motor ruined.....or

From what I have heard is that the newer motors are perfectly ok if the belt snaps, does the same apply to this older one.

[nickgroves0308]

Having read several posts on several goldwing sites regarding timing belt replacement, I would absolutely advise you to change the belts immediately. I just changed my belts and tenstioners (38k miles on bike) last week. If the belts fail you risk catostophic engine failure. Valves and pistons colide = major problems.

That being said, I did roll the dice and I put a couple thousand miles on my 82' wing before ever changing the belts. There is just no way of knowing if the bike with run fine with no belt failure or if one will snap on your first ride. Better to be safe and change them out.

[cbx4evr]

Interference engine = big $$$$$ when a timing belt brakes.

If the belts are 30 years old I would certainly put changing them at the top of the to do list.

[trike lady]

I'll add the same, change the timing belts because if they should break the end result is engine damage.

[raggun]

So there is a difference between older and newer models in the effect of a timing belt snapping.

I am at least told by my local Honda dealer that on the newer models nothing happens to the motor, the bike just stops running until the belts are replaced.

[Goldwing 80]

The early engines are an interference engine.If they snap,Mr. valve will meet Mr.piston,and they wont get along!

[RoadRogue]

As the others have said,yours is an interference engine. If a timing belt breaks while the engine is running the pistons will hit the valves(interferance) . If you have this happen and you get lucky you will have only bent the valves,worse is the valves will punch a hole in the top of your piston or pistons.And even worse yet is bent valves AND holed /broken piston AND bent rods. You can replace valves relativily cheaply but anything more than that it would be cheaper to replace the engine. Just be patient and wait till you have new belts installed, I know its tough but if the unthinkable happens you will be kicking yourself for years to come.

Ride safe and enjoy the new stead.

[raggun]

Does anybody know when the Goldwing engine changes from an interference engine to a non interference?

Knowing whitch kind of engine you have is pretty valuable info.

[WingAdmin]

ALL Goldwing engines, from GL1000 up to GL1800 are interference engines.

A belt break can cause as little as a couple of bent valves to as much as perforated pistons, damaged connecting rods, and more.

[thrasherg]

So there is a difference between older and newer models in the effect of a timing belt snapping.

I am at least told by my local Honda dealer that on the newer models nothing happens to the motor, the bike just stops running until the belts are replaced.

Not to be rude, but I think your dealer is an idiot!! All modern engines are interference engines and will have very bad results if a timing belt breaks.. In the older days we had low compression engines (Because we didn't have the knowledge/skills to build high compression engines) and they could get away without damage, but any modern engine will be a different story. Any petrol engine designed after about 1960 will probably be an interference engine. Some people do get away with broken belts not damaging the engine as it depends where the cam stops when the belt breaks, but that is just good luck!!

Gary

[WingAdmin]

Not to be rude, but I think your dealer is an idiot!! All modern engines are interference engines and will have very bad results if a timing belt breaks.. In the older days we had low compression engines (Because we didn't have the knowledge/skills to build high compression engines) and they could get away without damage, but any modern engine will be a different story. Any petrol engine designed after about 1960 will probably be an interference engine. Some people do get away with broken belts not damaging the engine as it depends where the cam stops when the belt breaks, but that is just good luck!!

I don't know about 1960....my crappy old 4 cylinder 1979 Mustang had a non-interference engine (I know, because I broke the timing chain on it), but you're right about two things: virtually all modern engines are interference engines, and the guy's dealer is an idiot.

[milkman00]

I purchased a 1977 gl1000 a few months back, been an on going project for me to learn on.... Unfortunately broke a timing belt. I was at a stop light, hoping damage was minimal, did a compression test, valves 1 and 3 seem are really low. Being new to this scene, was wondering if I should skip replacing valves myself and take to a shop.Also when I adjusted the valves they were REALLY tight I adjusted back out to .oo4, unfortunately after belt broke, could that have been the cause?

[RBGERSON]

It's not hard to change out valves but takes some tools..spring compressor the oen most don't have but there are ways around that too., should lap the valve seats while you're at it, new seals..all of it done on a bench..not on the bike that's nice.. or on the kitchen table in the A/C.




?? what's more important to you money or time??

[oldgold82]

There are still many non interference motors. They are usually the small displacement econo car motors, but not always. There is also a second type of interference these days on dohc 4 valve per cylinder motors your pistons and valves do not interfere but open valve paths might. I think this is more common with timing belts skipping a tooth rather than completely breaking. That said, a lot of cars today have variable timing chains in cases were the engine is interference. Also, pretty much every diesel engine I know is interference, the biggest gripe I hear from Volkswagen diesel owners is that they HAVE to change the timing belt every 60k or else. That's an expensive regular service.

[jimcooper]

I think the newer motors just use notched pistons. We used to do it by hand to get high compression VW motors. Can you get them for goldwings? Is there enough material to have it done?

Jim Cooper

[DenverWinger]

In my '85 Toyota Camry (350,000 mi) I had one timing belt jump 6 teeth after 25k mi, and another one break after 60k Mi. I've been trying to replace at 75k mi but these two didn't make it that far.... Totally non-interference, replace the belt and go!

[ekvh]

Notching pistons?? Good question. They would have to be pretty deep and would weaken the area between the outer edge of the valve and the piston rings. There isn’t a lot of room there, but maybe. If you did both valves and then shaved the head enough to restore compression it might work. There’s some meat in the piston, but I have no idea if there’s enough to be safe.

I blasted pretty deep into a 1200 piston trying to use 75 cams in a 1200 head. That was a giant FAIL. I have not ridden it enough since putting the stock ones back in it to say if it’s safe. I could envision the edge of the piston cracking and seizing up.

If you can do it yourself—-??? And do it with a proper machine and cutter to maintain the angle the valve comes in. I did the above with sandpaper on the valves and let it get too wide.

[DenverWinger]

I blasted pretty deep into a 1200 piston trying to use 75 cams in a 1200 head. That was a giant FAIL.

What happened? Notch failed (too deep) and hole in piston?

[jimcooper]

Seems like a good shop could use new pistons and weld a zig zag behind the area and balance them.

[WingAdmin]

Seems like a good shop could use new pistons and weld a zig zag behind the area and balance them.

Problem is, if a piston fails like that or is holed, it's not usually just the piston that's damaged. If you get bits of metal going through the engine, you can get valvetrain damage, and most importantly smooth bearing damage - and bearings aren't available for these bikes anymore.