Dedicated To The Smallest Of Skiffs banner
21 - 30 of 30 Posts

·
Zephyr Cove is on FIRE!
Joined
·
12,531 Posts
Knock off parts are irritating as hell.
Yes they are. China goes as far as printing counterfeit packaging these days. I can get a Powerstroke oil filter off eBay for $15 less than a certified dealer but they are fake. The filter media breaks down and will cause a massive engine failure...all to save $15.
 

·
Registered
2006 Kirkland 17
Joined
·
9 Posts
Discussion Starter · #22 ·
I messed around with the floats and it still feels restricted. Taking it to a mechanic on Saturday, will let everyone know what I did wrong
 

·
Registered
2006 Kirkland 17
Joined
·
9 Posts
Discussion Starter · #24 ·
I got it back today and she ran like a charm. They went through and cleaned the carbs and the water line for the cooling system. Ends up I was missing a ground for one of the cylinders… I’m an idiot. The line for the water pump was also partially clogged, causing an overheating issue.
At WOT I’m seeing 5000 RPMS not loaded down and just myself. Getting about 35 mph when properly trimmed. Anyone have any suggestions for a prop that they use with their 50 yammy on a skiff? I’m wanting to get 55 or 56 out of this motor when it’s just me and 39/40 MPH.
 

·
I Love microskiff.com!
Joined
·
253 Posts
What boat are you running? I have Caimen with tunnel and 50 yamaha 2 stroke. I have been trying different props. I have a 4 blade PT with no cup and it cavitation badly. I saw 5500 rpm with that prop. I may try to cup it some. It is a 10 pitch. I tried a Solas 11 pitch with cupping and cut rpms down to about 4K. I have Jack Foreman prop and it has worked the best but still cavitates . It is 11 pitch 3 blade. I need to go back to Foreman and see what to do next.
 

·
Registered
2006 Kirkland 17
Joined
·
9 Posts
Discussion Starter · #26 ·
What boat are you running? I have Caimen with tunnel and 50 yamaha 2 stroke. I have been trying different props. I have a 4 blade PT with no cup and it cavitation badly. I saw 5500 rpm with that prop. I may try to cup it some. It is a 10 pitch. I tried a Solas 11 pitch with cupping and cut rpms down to about 4K. I have Jack Foreman prop and it has worked the best but still cavitates . It is 11 pitch 3 blade. I need to go back to Foreman and see what to do next.
It’s basically a Mitzi 17. I have a spare prop that I’m going to try out. Not sure what pitch I have on mine right now but it seems like I can pump it up some. Thinking I’ll probably get something 1/4” smaller. Is a higher pitch preferred for hole shot or does that just deal with going from 3 blades to 4 blades?
 

·
I Love microskiff.com!
Joined
·
253 Posts
I am not that up on propellers choices. Usually higher pitch is for speed and lower pitch is hole shot with some loss of top speed. Some believe the 3 blade will do as well or better than 4 blade. I had a 4 blade on a Mitzi 15 and it was a really good prop. Do not know pitch of that 4 blade. It never slipped or cavitated. I am having trouble getting prop for Caimen with tunnel and 50hp Yamaha 2 stroke.
 

·
Zephyr Cove is on FIRE!
Joined
·
12,531 Posts
I am not that up on propellers choices. Usually higher pitch is for speed and lower pitch is hole shot with some loss of top speed. Some believe the 3 blade will do as well or better than 4 blade. I had a 4 blade on a Mitzi 15 and it was a really good prop. Do not know pitch of that 4 blade. It never slipped or cavitated. I am having trouble getting prop for Caimen with tunnel and 50hp Yamaha 2 stroke.
That is not really how props work. There are many more factors involved as to how a prop makes a hull and outboard move than just pitch and three vs four blades.

Your outboard has a red line which is the maximum RPM it can effectively run without risking damage to the power head. Running a prop that can’t reach that RPM is dogging your outboard and killing not only your fuel economy but also overloading your engine which is like driving a truck with a standard transmission starting out in third gear. Your outboard has one forward gear so you need a prop that can make the best out of the power band which is the RPM range the engine is designed to run. Prop diameter, pitch, cup, cup placement, number of blades, rake, blade shape, barrel size, barrel flare, porting etc are all factors that can be combined to make a prop do different things.
There is also a myth about hole shot props are four blade and speed props are three blade. That is an incorrect generalization started decades ago by internet armchair prop gurus that has stuck around far too long. I’m no prop guru but I can hold my own.
I think instead of thinking you need to tell Jack Foreman what to do to make that prop work you should give him numbers and how those numbers change in different scenarios. If you have a three blade custom Foreman and it’s blowing out he’s going to ask you at what point does it start losing grip and what is your WOT RPM when you have the trim tabs, trim, jackplate and weight distribution optimized.
When I open my full time boat shop I’ll be incorporating guided fishing trips and also offering customers time on the water with me showing them how to run their boats and find the sweet spot then if it needs any tweaking I’ll make suggestions and make those changes either at the boat ramp or back at my shop. Lots of people think they are able to run a boat but could use some help.
 

·
Registered
Joined
·
4,965 Posts
Speaking of props... the first thing I try to do on any skiff is to look exactly where the motor is sitting on the transom before anything else (exact height of that plate in relation to hull bottom), then make a careful examination of the actual hull bottom using a known straight edge to see exactly what the configuration of the hull itself is... After that it's all the stuff Smack has mentioned...

One of the reasons I don't like jackplates is that it adds one too many variables for me... but that's just me...
 
21 - 30 of 30 Posts
Top