Prop advice please

[captpierre]

Chewed the tip of one blade on my stock '07 Yammy 115 4str.last fall.

 

Thinking of having this one repaired in Buckhorn but thought it may be best to get a new one and use the repaired one for a spare.

 

I'm too cheap to buy a SS prop.

 

Not sure of the pitch on my current prop but I have 2 concerns.

 

1. Hole shot slow with 3 or more people in the boat (17.5 ft Lund)

No problem with 1or 2.

 

2. Can't get trolling speed down below 2.3 mph. Engine idles around 700 rpm.

 

Likely will get an aftermarket aluminum.

 

Should I get a different pitch? Or a 4 blader? Or stick with same?

 

What would you do?

 

Peter

[DRIFTER_016]

Need more info.

What is your WOT throttle with the current prop?

Model # of current prop?

[Tim Mills]

check previous thread "prop question" , may be some info that works for you there

[BillM]

Toss some drift socks out behind the boat to slow your trolling speed down.

[bigbuck]

If you are running at or close to your max rpm hen stick with what you have. If you have 2-300 rpm of room, go to the next size down, ie. current prop 21p, go to a 19p. You may lose a couple ofmph at top speed but boat will plane more efficiently saving you fuel.

[captpierre]

So Guys.

 

I have more info from this weekend.

 

Current prop is 13 1/4 x 17.

 

WOT with just me and a full tank of gas is 6200. 42 mph. (with tip of one blade chewed)

 

the decision remains, 1. buy same 2 . 4 blade aluminum. 3. change prop size/pitch

 

I would prioritize hole shot and slower trolling speed over top speed

 

thanks lots

[DRIFTER_016]

@ 6200 RPM WOT you are under propped according to your motors specs (RPM range 5000-6000).

To get you down into a safer RPM range you should increase pitch to 19" Prop diameter of 13" or 13 1/4".

This will drop you to around 5800 WOT. You will gain a little on the bottom end and lose a bit on the top end.

Trolling speed will be slightly negatively impacted though.

[Bernie]

Drifter is absolultely correct on the too high RPM's.

But he would gain top end speed going bigger pitch and lose some holeshot.
But it would also increase the trolling speed too.

 

I'd highly recommend going SS though. A good propeller can really improve performance.

Edited May 28, 2014 by Bernie

[DRIFTER_016]

Drifter is absolultely correct on the too high RPM's.

But he would gain top end speed going bigger pitch and lose some holeshot.

But it would also increase the trolling speed too.

 

I'd highly recommend going SS though. A good propeller can really improve performance.

 

 

HEHE my bad. Took my several minutes to remember which way to go in pitch to reduce RPMs.

[BillM]

A 13x17 seems to be pretty small. We run almost the exact same rig as you (Lund 1700 Pro Sport, Yami F115) and we've got two props.. A 13x19 and a 13.25x19. The 13.25x19 really gets out of the hole well and loses a few mph on the top end. The 13x19 still gets out of the hole ok and I've seen 49MPH on the GPS unloaded with half a tank of fuel. Even loaded all the way down I've got zero issues getting on plane quickly with the 13.25x19 prop.

 

I think I'll be taking Daves suggestion and looking at a 4 blade 13x20 in the near future.

Edited May 28, 2014 by BillM