The Engine is dead, Long live the Engine!

[macd]

As you're no doubt aware peak power can be about 60% of maximum allowable rpm; so the correction re Yamaha is valid - the other apocryphal. ;-)

Nothing like 60% on those things, Charles. More like 90%. And no point revving much higher, anyway: power curve plummeted.The only apocryphal reference was your original one.

 

[BurnitBlue]

Think you will find that if you went the Beta route they sell a set of fabricated brackets to pick up on your existing bearers. Most modern engines are on a narrower base than the BMC.

I investigated Beta and their custom bearer brackets. From Greece Beta repeatedly diverted me to the Greek agent. His prices were high and apart from that I had to pay around 5000 euro instead of pounds.

Also I wanted to use he same shaft. With Beta's custom bearer brackets I was about an inch short from gearbox to shaft coupling. My own construction allowed me to place the engine further aft to allow clearance at the p-bracket. The gearbox is cone clutch and needs at least a few centimeter clearance to the prop.

 

[Tranona]

Measured a 33 prop today and it is 13" diameter, could not tell the pitch. No room for anything bigger.

 

[capnsensible]

Measured a 33 prop today and it is 13" diameter, could not tell the pitch. No room for anything bigger.

Many thanks for that! Owe you one, :encouragement:

 

[capnsensible]

If the boat is a moody33 then the BMC had direct drive I believe due to lack of hull clearance but I am sure this will be all on the Moody owners site
Ignoring their information would seem somewhat lacking in common sense

Top tip. Lots of very useful stuff on their website.

My old engine is sneaking ashore bit by bit. The engine compartment itself has had a severe looking at, several times!

 

[Egarciadea]

Hello Charles

Would you please tell me where did you buy your Yanmar engine, and how much does it cost, I am looking for a 3YM30, mine is broken too

Thanks,

Ernesto

 

[Mrnotming]

Digression alert:


I'm afraid you'd expect wrong, Charles, not least because Yamaha never made such a triple. Even the racers amongst those that did revved to around half that. The factory Kawasaki KR750 developed peak power at 9500rpm. Some of the tiddlers, such as Suzuki's RS67 (125cc V4) which peaked at 16,500rpm, were rather giddier.

I bow to your superior knowledge, my youthful follies being amongst much earlier 4-wheel variants of motors which had 110-150mm strokes and peaked @ 1250r pm.
As you're no doubt aware peak power can be about 60% of maximum allowable rpm; so the correction re Yamaha is valid - the other apocryphal. ;-)[/QUOTE]
Well Done Charles_Reed, you have succeeded admirably in digression!
What was once a simple typo, has now become an adventure - smoke and mirrors style!
Dangling the Wikipedia: Apocrypha are works, usually written works, that are of unknown authorship, or of doubtful authenticity, or spurious, or not considered to be within a particular ..
Would such definition serve to elucidate or are we misled?