SR4, prop size?

[Firefly]

I have a question for SR4 owners or indeed anyone in the know.
What size prop would you expect to see on an SR4 with a 50 hp 2 stroke?

[Nick Hearne]

I have a Yam 3 pot 2 St 50hp on mine and Julie at Steel Developments suggest 11.3x13 aluminum prop which is spot on!

[Nos4r2]

Mine , running a Merc 50 2 stroke (not bigfoot) was spot on with a 10 3/8 x 14" prop.

[SimonStDavids]

I have a 11 x15" on mine. But I have a 55 on mine

Plus it is only me 99% of the time. I think if it was going to be more than me or for towing stuff I would drop to a 14" or if I could find one a 13.5".

The motor came with a 13" and it was over revving with just me.

[Wibs]

Mine has a 2003 Tohatsu 2st 50hp, running a 11.1 x 14" 3 blade. It works for me, however I also run a 13" as well.

The 13 is better for me if I have crew and/or a bit of rough stuff,

The 14 gives me a few more knts at WOT, and seems better when solo.

[Nick Hearne]

I have also a stainless 11.75" X 17 pitch prop which came my SR4 & the Yamie 50hp will only rev to 4100 rpm, top speed is down just a bit but the difference in get up and go is a large factor as with the smaller prop its a real pocket rocket

[Firefly]

Thanks for the response.

[Chris Caton]

don't know if they'll fit, but I've got a couple of props that I tried on my sr4 with honda 50, you're welcome to try them if you're any where near nth Wales or Merseyside

[Firefly]

Originally Posted by Chris Caton

don't know if they'll fit, but I've got a couple of props that I tried on my sr4 with honda 50, you're welcome to try them if you're any where near nth Wales or Merseyside

Thanks for that kind offer. Do you know what size they are?

I got 4 props with this boat due, I think, to the previous owners tendency to cruise in rock infested water or even in no water at all. The diameter size stamped on the props bear no relationship to the actual size. I'm guessing they have all been filed down over the years as the shape is wrong and they are all around 10.5" diameter. No wonder my revs are too high.

I am not near you but I'd buy one if it was the right size.

[Firefly]

If it were the right size....just before the grammar police respond..lol

[Firefly]

Originally Posted by Firefly

Thanks for that kind offer. Do you know what size they are?

I got 4 props with this boat due, I think, to the previous owners tendency to cruise in rock infested water or even in no water at all. The diameter size stamped on the props bear no relationship to the actual size. I'm guessing they have all been filed down over the years as the shape is wrong and they are all around 10.5" diameter. No wonder my revs are too high.

I am not near you but I'd buy one if it was the right size.

The actual diameter of the current prop is 9 inches.

[Wibs]

Originally Posted by Nick Hearne

I have also a stainless 11.75" X 17 pitch prop

Wow....did it ever get on plane.?

Mines still got the flooding hull and you can really feel it from a standstill. I'd imagine the 17" takes a while.

Shame really, as I've always wanted to know what sort of difference a s/s prop makes- but I've not had the cash to experiment.!

Plus, the general consensus is to stick with ali in case you strike something on the bottom.

[Firefly]

Originally Posted by Wibs

Wow....did it ever get on plane.?

Mines still got the flooding hull and you can really feel it from a standstill. I'd imagine the 17" takes a while.

Shame really, as I've always wanted to know what sort of difference a s/s prop makes- but I've not had the cash to experiment.!

Plus, the general consensus is to stick with ali in case you strike something on the bottom.

Yes, no problem but revs are too high of course.

[Chris Caton]

Originally Posted by Firefly

Thanks for that kind offer. Do you know what size they are?

I got 4 props with this boat due, I think, to the previous owners tendency to cruise in rock infested water or even in no water at all. The diameter size stamped on the props bear no relationship to the actual size. I'm guessing they have all been filed down over the years as the shape is wrong and they are all around 10.5" diameter. No wonder my revs are too high.

I am not near you but I'd buy one if it was the right size.

both are in the caravan at Caernarfon, but there's a ally 10.5" x 13" pitch which came with the engine, only been used for a hour or so, too small pitched for the honda, and a 11 1/8" x 13" stainless, which again is like new but too small pitched, I tried a 11" x 14" which was better for was still allowing the honda to hit the limiter at 6200, I've found a 11" x 15" ally to be the best so far. to be honest, it's a bit hit n miss what'll suit your setup, I know there are calculations you can use, but there's so many variables i found the best bet was to just fit one n try it out, luckily there's a brilliant prop builder / refurb place in Caernarfon which is worth its weight in gold, literally

[Firefly]

I am dealing with them at present. As you say Chris, they know their stuff.

[Nick Hearne]

Might be a black art but some know better (or maybe just lucky?) there stuf and having had a chat with Julie at Steel Developments she suggest 11.3x13 aluminum prop which is spot on with the revs first try no guessing or collecting props!

[Chris Caton]

I think you're right Nick, there are some about who know there stuff, but it's deffo a black art to me, but the likes of steel developments n these guys at Caernarfon give you faith that the knowledge is still there, they rebuilt a damaged prop for me n it looked like new, top prop shop

[Firefly]

11.3 x 13 is the size I am going for.

I'll report back.

Thanks