Yamaha Timing Belt Replacement?

[Tight Roll]

My 225 hp motors are within the range of the recommended 1000 hour replacement of the time belts. My mechanic (not a Yamaha dealership) advised against it and said it was a waste of money as they never break. I personally have never heard of anyone having issues. Are people replacing belts as Yamaha recommeds

 

[saanauk]

Believe Yamaha went away from the 1000 hour replacement guideline. Think it is just to inspect and keep an eye on it for wear. Even with that I had my 2006 Yamaha 250 timing belt replaced in 2021 just for a piece of mind. Figured a 15 year run on the original timing belt was decent.

 

[noluck]

timing belts are cheap compared to where you might be if it broke let alone the cost of the engine damage

 

[Foxsea]

Believe Yamaha went away from the 1000 hour replacement guideline. Think it is just to inspect and keep an eye on it for wear. Even with that I had my 2006 Yamaha 250 timing belt replaced in 2021 just for a piece of mind. Figured a 15 year run on the original timing belt was decent.

With 1600 hours our F115 timing belt looked new. On most cars with belts, about 3000 hours is normal. Yamaha is very early on many recommendations.

 

[ship happens]

It's the tensioner that fails. Expensive little tensioner. If the tensioner fails, the belt will most likely skip a tooth. Usually it starts making noise before it siezes up.

 

[kingblazer84]

interference engines are one thing you don't want to skimp out on maintenance items like timing belts, just like vehicles there is a reason they put time frames on those items.. its a ticking time bomb otherwise or pay to play imo.

 

[Foxsea]

interference engines are one thing you don't want to skimp out on maintenance items like timing belts, just like vehicles there is a reason they put time frames on those items.. its a ticking time bomb otherwise or pay to play imo.

You are entirely correct. I just think 1000 hours is a little ridiculous because:
1) it's a Yamaha
2) car experience (3 x that)
3) it's expensive preventative maintenance.
Each to his own level of comfort, I suppose. Commercial users put thousands of hours on before considering a change.

 

[scott craven]

anybody have any experience with a belt failure ?
how catastrophic were the results ?

 

[ship happens]

I haven't seen a catastrophic failure as of yet on these, however I'm sure it's happened. I've seen belt damage and skipped belts a lot when tentioners bearings let go and get worn out. Usually when the tensioner goes it takes the health of the belt with it. Seen this happen probly 10 times in the last 15 years. Some go well before 1000 hours and some go after that. Either way it's going to happen. Just a matter of when. That tensioner is a real POS


I'll add that on the VBlock engines, that belt is turning 2 large cam pullys. There's a lot of resitance there. Its using the same tensioner as the inline engines.

Yamaha does not make the tensioner. It's a POS tensioner that is used around the globe on various different machines.

 

[profisher]

You are entirely correct. I just think 1000 hours is a little ridiculous because:
1) it's a Yamaha
2) car experience (3 x that)
3) it's expensive preventative maintenance.
Each to his own level of comfort, I suppose. Commercial users put thousands of hours on before considering a change.

1/3 the time but way more rpms for an outboard. Cars don't see 4-6000 rpms for very long periods like boat engines can.

 

[trophywife]

It's the tensioner that fails. Expensive little tensioner. If the tensioner fails, the belt will most likely skip a tooth. Usually it starts making noise before it siezes up.

this, had it happen on two of my old motors.. bent an exhaust valve on one and royally f'd another.. idler/tensioner wore. belt still looked good.

 

[ship happens]

this, had it happen on two of my old motors.. bent an exhaust valve on one and royally f'd another.. idler/tensioner wore. belt still looked good.

Yeah if it skips a tooth or 2 it's fine usually. Won't run for ****. If it skips a few then your in for a big job. Especially on the V Blocks. Belts get stretched out after a while on pretty much all machines. That's alot of stress the take turning those cams on these type machines

 

[Foxsea]

1/3 the time but way more rpms for an outboard. Cars don't see 4-6000 rpms for very long periods like boat engines can.

Not arguing but most guys seem to cruise around 3600 rpm. I do. YMMV
If it gives you comfort, replace it. The tensioner and the belt are easy to inspect.

 

[Gibson19]

I have a 2018 yamaha 300hp. The engine at idle did not sound good. Almost a tinny sound.
Took it out and not long after the engine was clearly not right. Took it to the local yamaha dealer who confirmed the timing belt had jumped. So far in fact he could not retime it as a valve was toughing a piston. The cause was a incorrectly installed tensioner. I poped the heads off to be sure there was no damage. It was fine.