Osprey 18

GreigS · 08 December 2011, 10:34

After a bit of advice, I've got an Osprey 18 with a yamaha 85hp (1992). Was thinking on getting a newer engine, but need to know the max hp/weight for the boat before I start looking.

Cheers

Greig

cjj216 · 08 December 2011, 20:58

Hi greig. What model is it? I had an xr18 with a dt140 on it. In all honesty it was seriously overpowered. That said the boat never complained. In the right hands I'm sure it was safe. Trimmed correctly it sat well even with big lump on back. Lots of chain in front locker helped. I think a 90 would be plenty.

GreigS · 09 December 2011, 10:24

Hi, the model is the Osprey 18, not the XR18. The manufacturers plate has long gone, so would like to know what the original manufacturer specs were for hp and engine weight. Have had a look on the osprey owners site etc, got some history about the 18, but no info on engine size/weight. So any info is much appreciated.

Downhilldai · 09 December 2011, 11:49

Is it an Osprey Eagle? They were around 18' long.

Hightower · 09 December 2011, 12:08

There is a little artical about the Osprey 18, but no mention of engine HP. Look here: Home - Osprey & Vector Marine RIB Owners' Association

GreigS · 09 December 2011, 15:43

Yeah that's the info I found about it.
Here's a photo of it.

Hightower · 09 December 2011, 15:52

I would have thought a 90 would be about on the money, but if you wanted to push it, I would have thought a 115 2 stroke was a safe upper limit, keeping your eye on the engine weight as not to destroy the handling

Pete7 · 12 December 2011, 18:57

Greg, I doubt you will achieve much with a bigger engine. You are talking about a boat that was built in the days 2 x 40 hp mariners was considered more than sufficient. The hull is light and slim, it would be a shame to put a big engine on and ruin the handling just for a bit of extra speed.

What's more if your Yam 85 is from the same age it's a testament to those engines. I would have the compression ratios checked and if good leave alone. We have one in the diving club. I first saw this engine in 91 and it wasn't new then. It was used by a diving school for a decade before we obtained it. We cured a fuel leak and put the right prop on it then ran it for another decade. Since it was never serviced by the dive school we can't get the thermostat out or risk shearing the bolts so leave well alone and just use it. Rattles a bit but always starts.

I wrote the Osprey history article btw.

Pete

GreigS · 12 December 2011, 19:45

Guys, thanks for all the info. Don't think I would go above 90hp anyway.
Will keep going with the 85hp for now, but if a newer 85-90hp yam was up for sale..........