Rotax 914 Reliability

[pitfield]

I'd be grateful if anybody with 914 experience would provide their views on 914 reliability. I'd love the extra horsepower but the 914 seems to suffer reputationally because of reliability issues. Thanks.

 

 

[eightyknots]

B*u*M*p (I'm interested too)

 

 

[Guest Maj Millard]

First of all the 914 is only a 1200 hour TBO engine. The standard 100 Hp 912 are now 2000 Hr TBO. The 914 is the 912 80 Hp engine, with a wastegate controlled turbo charger on it. That turbo is expected to produce 35 Hp !!...That's almost 50% of the original horsepower !....The electronic side of it is controlled by an electronic computer box, which is feed info from many sensors situated throughout the engine, intake and exhaust. The whole electronic system looks like it was stolen from a very expensive Mercedes Benz............it is possible to understand it, but very mind-numbing to do so from the maintenance manual...mess with it too much, and your in big trouble. quickly. If your away from home in the bush, you'll be walking before you fix it. The standard 912 80 or 100 Hp by comparison, are very easy to understand, very easy to fix, and extremly reliable !..

 

My prediction ?: ...The 914 will slowly be replaced by the new 912i, or a further development of that engine.............................................................................Maj...

 

 

[turboplanner]

Having been through similar mind numbing changes when very sophisticated changes were introduced to truck engines my advice to someone like yourself is to get into grabbing that knowledge as regularly as you can.

 

I used to work next to the Holden Service guys in Melbourne when the first computers went into the Commodore, and all day long you would hear "You had a problem with the computer, and now it won't work? Did you use a normal voltmeter? Well that inputs 'x' and the maximum load the computer will take is about one thousandth of that, so you've burnt out the computer" apparently followed by a string of expletives from the other end, followed by "No, I'm afraid the only way to fix it is with a new computer and that will cost you $800.00"

 

Then we had the case when everyone fell about laughing after: "Let me get this straight madam, you parked the car in the garage...........turned the key off, took it out, and went inside the house.....and the car just started itself and drove itself forward through the back of the garage......."

 

The smiles soon came off the faces when a second car self started a few weeks later and there was feverish activity and a recall.

 

Then there were the cases when trucks would sense an issue and reduce power to save the engine and limp home.....from two hours west of Ceduna.

 

And then we got self diagnosis - the engine would shut down to idle and show fault code 982. Problem was no one had a clue whether it meant a potential catastrophic engine failure or the fuse to the cigarette lighter had blown.

 

The truck drivers used to screw up the pumps to increase the power output, which shortened engine life and one day a Cummins guy proudly told me they had a new computer in a sealed box which would drop the engine to limp home mode. Six weeks later he moaned that someone had managed not only to break into the box and bypass the safeguard, but had found a US supplier who would profile chips to whatever the driver wanted and was selling them through truck stops.

 

Then the injection pump was replaced by a pump which just charged the whole manifold (common rail) and injection pressure was raised from around 2000 psi to 20,000 psi, and we all had to go out and tell the mechanics that 20,000 psi would send a stream of diesel straight through your body, so cracking injectors to bleed them could now get you killed.

 

With common rail, injector timing was not only triggered electronically, which was much more precise, but fuel could be injected at several points as the piston approached and departed TDC, and also used to get a substantial flame front going to burn the residue off a catalytic muffler.

 

That's all old history now, and a mixture of on board self diagnosis and brilliant diagnostic tools should see you spending most of your day with your feet up, and earning money like a dentist Maj.

 

 

[Wayne T Mathews]

First of all the 914 is only a 1200 hour TBO engine. The standard 100 Hp 912 are now 2000 Hr TBO. The 914 is the 912 80 Hp engine, with a wastegate controlled turbo charger on it. That turbo is expected to produce 35 Hp !!...That's almost 50% of the original horsepower !....The electronic side of it is controlled by an electronic computer box, which is feed info from many sensors situated throughout the engine, intake and exhaust. The whole electronic system looks like it was stolen from a very expensive Mercedes Benz............it is possible to understand it, but very mind-numbing to do so from the maintenance manual...mess with it too much, and your in big trouble. quickly. If your away from home in the bush, you'll be walking before you fix it. The standard 912 80 or 100 Hp by comparison, are very easy to understand, very easy to fix, and extremly reliable !..My prediction ?: ...The 914 will slowly be replaced by the new 912i, or a further development of that engine.............................................................................Maj...

Hmmm, gazing into my crystal ball, all misty (or is that blurry) eyed, I can see it is saying you're right Maj. But Turbz has a point, you know. The young blokes who invest in, and then learn how to use the diagnostic equipment that will be needed in the future for a turboed 912i as an example, will wind up earning like a dentist. Trouble is for us though, do we really want to be one of them? For sure it's the way of the future, but...

 

I just pulled the pots on my old girl's C85. Cleaned the valve stems and guides, lapped the valves, replaced the pushrod tube and induction trunk rubbers, and the plugs. Felt comfortable and relaxed doing it. Sort of like sitting in front of the fire with my slippers on, sipping a good coffee. Life is good.

 

 

[cscotthendry]

"Simplicate and add more lightness" :William Bushnell Stout (Sometimes credited to Clarence Kelly Johnson)

 

 

[damkia]

"Simplicate and add more lightness" :William Bushnell Stout (Sometimes credited to Clarence Kelly Johnson)

I always wondered where that quote came from. It's one of the ones my old man used to come out with from time to time.

 

 

[Mick]

First of all the 914 is only a 1200 hour TBO engine. The standard 100 Hp 912 are now 2000 Hr TBO. .............................................................................Maj...

Maj, Flood's latest ads say "2000hrs TBO Rotax 912/914" so to me that indicates the 914 has been lifted to 2000hrs also.

 

.

 

 

[bones]

Maj, Flood's latest ads say "2000hrs TBO Rotax 912/914" so to me that indicates the 914 has been lifted to 2000hrs also..

Correct very correct, and yep after you get your head around it they are not too bad to get working properly, but saying that i would prefer they not have all the elctronic crap on them, because they are not efi, so why did they have to complicate them so much, now the new efi engines they could be a damn night mare, dont know never seen one yet.

 

 

[rankamateur]

Correct very correct, and yep after you get your head around it they are not too bad to get working properly, but saying that i would prefer they not have all the elctronic crap on them, because they are not efi, so why did they have to complicate them so much, now the new efi engines they could be a damn night mare, dont know never seen one yet.

But European emmission control laws are ruling the day and the 914i or the 130Hp 914iS must surely follow the 912iS

 

On the other other hand , 21% fuel saving is the marketing bait to justify the extra weight and cost of the 912iS. Punching out a 914iS to compete with the 130Hp UL motor might be a bit hard to market from a Rotax price point.

 

 

[eightyknots]

Then we had the case when everyone fell about laughing after: "Let me get this straight madam, you parked the car in the garage...........turned the key off, took it out, and went inside the house.....and the car just started itself and drove itself forward through the back of the garage......."

The smiles soon came off the faces when a second car self started a few weeks later and there was feverish activity and a recall.

Yikes!