Man vs. Diesel Starter Motor

[SecondBase]

Does a bicycle crank create enough torque to turn over or "pedal start" a 3 cylinder Betamarine diesel?

[a64pilot]

If geared correctly, yes
However usually a Diesel is hand started by releasing compression, then spinning it up as fast as you can and then allowing compression, using inertia to start the thing.

[daletournier]

Does it have decompression valves?

Sent from my vivo Y35 using Cruisers Sailing Forum mobile app

[SecondBase]

Great question. I'm not really sure. It is a Betamarine B-25HE (25BHP at 3,500 RPM). Can I see the lever(s) on the engine?

[Bill Seal]

starting boeing vintage - Bing video

Or, if you're lazy, a Coffman cartridge starter.

[Sailmonkey]

There are no decompression levers on that engine. Starting it with anything but the electric starter motor is going to be extremely difficult

[jimbunyard]

If you hook it to a generator and use it to charge the battery...

[Adelie]

Without decompression levers, the only alternative to electric start I'm aware of are spring starters.

Installing involves removing the existing starter so this is not an easy backup arrangement. And kind of expensive too.

http://www.springstarter.com/

[jimbunyard]

Hydraulic and air starters are also available, though generally for larger engines.

It really comes down to power output. A typical small engine starter is rated at about 1 kw, a typical human can generate about 100 watts.

So even if you geared the bicycle crank low enough to actually turn the engine over, it is unlikely you could spin it fast enough to start it, certainly not without a decompression device, and probably not even with one, unless maybe you're Lance Armstrong...

[double u]

pedalling with both feet I can get >300W for a VERY short period of time (youngsters of course up to 50% more...I don't think this is sufficient to start a 28hp engine without decompression levers (not to speak of the difficulty of setting everything up so one can pedal efficiently like on a bike...)

[donradcliffe]

No worries for someone who is in shape. The cyclists keep careful track of their power output.

How many watts can Mark Cavendish produce?
“You'd be surprised at my watts,” Cavendish says. “Most people who say that their maximum is 1,600 watts won't put out 1,600. My maximum is 1,580, and that is a lot. Not many guys will do more than a hundred more than that.

[double u]

if that is meant as "power at the crank" (not total energyrelease by the body including heat) then is total BS! champion mountainbiker can produce peaks of just over 800watts & 400 steady. everybody just climb on their ergometers (as I did yesterday...)
https://en.wikipedia.org/wiki/Bicycle_performance

[donradcliffe]

That's power as measured by the crank power meter. It may be for only 5 seconds or so, but the engine should have started by then.

[double u]

if a starter motor has 1,5kW - how are 400 or 500 watts or even the 800 of a champion going to be sufficient? the 1600 are BS

[double u]

just found:
Jan Ullrichs anaerob threshold was measured at 430W...
furthermore:
total output (this is including basic metabolic rate!) sprinting 100m: 2070W @41% efficiency =850W