pitch

Josh James · Jun 22, 2003

I own a 1983 Bayliner runabout. It is fiberglass and 16'11" long.It has a 1979 140 Horse Evinrude. I need to replace the prop but do not know what pitch the prop is. I do Believe it is the original prop. I was also wondering since this is original equipment if I need a new Hub. Please help for I am green to Boating.<br /> Thank You

moderator1 · Jun 22, 2003

Re: pitch

Moving to Outboards

Sherman · Jun 22, 2003

Re: pitch

I have a 115hp 79 and run it with both a 12-3/4" dia 19 pitch and a 12" dia. 21 in pitch. Your old prop may have been painted many time as the dia. and pitch are always on the outside of the hub area. My boat is a 16'-7" whaler. What you are looking for is the correct rpm 5500 at wide open throtle. As you increase the pitch the rpms will drop. Do not exceed the 5500 limit by putting on a prop with too litle pitch. I would start your trial with a pitch of at least 21"

boating brad · Jun 22, 2003

Re: pitch

i agree with sherman, 21 pitch because if im not mistaken, you have too much motor for that boat. you can confirm this by looking at the tag inside the boat somewhere, anyway it will say the max hp for that boat im thinking it should be about 115.

Josh James · Jun 23, 2003

Re: pitch

Now what problems might I encounter running a smaller pitch. I ordered an 18 pitch prop and was wondering if I need to cancel my order. Or If It might possibly run in the right Rpm range and be worth a try. The inspection plate says 90 HP

Sherman · Jun 24, 2003

Re: pitch

You are very likely to over rev the motor. I would guess that with an 18" pitch it will try to run 6000-6500 rpm. Other than that the 18" prop will provide you with a good hole shot and poor top speed. Did you ever find the numbers 0n the old prop.

Josh James · Jun 24, 2003

Re: pitch

The Old Prop says 13 3/4x15 If that is the number I need to find wich I think it is because there wasn't any other number on it other than a pert number

Sherman · Jun 25, 2003

Re: pitch

Yep 13 3/4 is the diameter and 15 is the pitch. But, this is a very low pitch for that motor unless your boat is very heavy.

Josh James · Jun 25, 2003

Re: pitch

It's A fiberglass hull, closed bow, I run a 9.9 hp kicker motor and a 24 volt trolling motor. It's kinda wieghted down but I don't know what it wieghs or comparision with other boats.

Sherman · Jun 26, 2003

Re: pitch

From what you say I would think that the 18" prop will be ok. Just watch your rpms. It sounds like your boat and equipment is somewhat hevier than mine. Does your boat have a tach?<br /><br />Sherm

Josh James · Jun 29, 2003

Re: pitch

I exchanged My Prop but couldn't get a 20 so I got a 19pitch. I do have a tach and will watch it close. Thanks for the help.

Josh James · Jul 6, 2003

Re: pitch

I took my boat out with the new prop.(12.7x19)I can only get my RPMs to about 2300, with full throttle. Needless to say my boat doesn't move very fast. My 9.9 kicker motor gives it competition.<br />

pitch

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