Johnson Engine Dealer

[RebelSS]

Can anyone recommend a danged GOOD Johnson Engine dealer, or specifically someone that KNOWS which prop my engine should have? My dealer keeps telling me I'm underpropped and my engine should have an 11x13 on it...it came from the factory with a 10x13. '95 Johnson 30 HP...tri blade; TTH exhaust. No, I don't have a tach on it to check if I'm at known WOT range of 5500 or not, dealer told me I'm below that when I had it in for an engine prob I couldn't track down. Anywho, I know my engines, been working on them since the 70's, and MY books all list a 10x13 prop. Any advice on someone who KNOWS this engine prop rating? Until I hear different, I'm running my 10X13.....appreciate any help, thanks!

[delcecchi]

How does the dealer know?  95 motors didn't have computers and diagnostic ports so far as I know. 

Al's is the big time dealer and used to handle OMC.  Are they not doing it for you? 

And going to an 11 by 13 isn't going to increase RPM at WOT.  Diameter of prop is limited by anti ventilation plate on motor.  Pitch is most important.  

What dealer are you working with? 

 

Edited October 4, 2015 by delcecchi

[RebelSS]

Al's is doing for me. Del, not following what you're saying...how does the dealer know what? RPM's are easy, ya hook a tach up to it like your old '67 chevy...same thing. On water or off.They DO have CDI power-paks, you realize,   John says thats what THEIR book says for prop...also that's the size I need to increase my RPM. I do know enough that size selection is inversley proportional to your RPM's...and so is prop  size. Dropping down in pitch 1 deg will give you higher RPM's...That's verbatim as we stood in the shop and talked "shop" for half an hour on Thursday.. You DO know the bros., don't you? Anyway, I just want to know if anyone has an app guide for the proper prop and pitch of that engine without a major discussion on who or what is working on it.....I can handle the engine stuff myself..just needed a part. 

Edited October 4, 2015 by RebelSS

[delcecchi]

Sorry, you said you didn't have a tach on it, but dealer knew what it was running at.  I didn't understand how the dealer could know what it runs at without a tach on the water. 

I haven't seen where people mess with prop diameter, only pitch.  I guess diameter would affect the slippage a little, thereby changing the WOT RPM. 

Me, I get stuff up north where my cabin and boat are.  I couldn't afford to buy stuff at Al's back when I was shopping.  Seemed to think everyone was a doctor or something. 

I can't think of anything to help besides putting a tach of some sort on it and taking a ride. 

Maybe something like this? 

http://www.harborfreight.com/lcd-automotive-multimeter-with-tachometer-kit-95670.html

or maybe

http://www.amazon.com/Docooler-Tachometer-Gauge-Holder-0~8000RPM/dp/B00HCB7K26/ref=sr_1_2?ie=UTF8&qid=1444003135&sr=8-2&keywords=tachometer

But, sounds like you have it under control. 

 

[RebelSS]

It ran well below 5500 RPM at WOT while being tanked at Al's. On water with my size and weight with gear and a buddy will bring RPM's even lower. I can hook up my multimeter auto tach on the water to it if need be. First, I need to find WHAT THE  %$#@ RECOMMENDED PROP FOR IT is. 

Edited October 5, 2015 by RebelSS

[delcecchi]

I would expect the rpm to be low in a static situation like a tank.  The resistance of the boat determines the rpm that can will be achieved.  If I can find something on line I will post it.

 

[boatfixer]

1. You've got to tap into the rectifier for your tach signal, not the pack. It's the gray wire leaving the rectifier. 

2. Call Jay at soderbloms, just search him on the interwebs. Listen to him, he knows more than most when it comes to this stuff

[delcecchi]

soderblooms

Good idea. 

[RebelSS]

That's what I wanted......thanks, boatfixer.