Question For Kenny 4800 MSL lake

[72SideWinderSS]

Hi Kenny,
Dale recommended I contact you about High altitude tuning.
I'm headed for Cascade Lake in Idehoe shortly and have a question for you concerning jetting. What jet size would you recommend for a 1979 Johnson 115 hp no mods (yet).

Also I have a 13X19 Michigan Wheel I plan to run there.
Here at sea level I turn that wheel at 5700 rpm.

Thanx,
jimmy

 

[walleyehed]

Re: Question For Kenny 4800 MSL lake

Need to drop the mains 3 sizes (.003), advance timing atleast 1-2 degrees above max, and it will likely require a 17P prop.
With the changes above, it may turn 5500 with the 19, but I think you'll be doing good to get 5300....the reason I would suggest the 17P.
Make sure it has the correct, factory sea-level jets before dropping 3 sizes.

 

[72SideWinderSS]

Re: Question For Kenny 4800 MSL lake

Thanx for the info.
If I rember right the carbs have 54c's in them right know, so drop to 51c's or is each number a step of .001" ?
I have a alum 17" that came on the old motor when I bought the boat 10 years ago, kinda used up abit but I have a prop shop close by.

Thanx again,
jimmy

 

[walleyehed]

Re: Question For Kenny 4800 MSL lake

Yes, you can go with .051's or .052's (51C or 52C)

 

[72SideWinderSS]

Re: Question For Kenny 4800 MSL lake

Kenny,

one more quick question.
My plugs are a med brown now, would you recomend I drop down a size or two now, and then drop two or three more when I get to the lake?
thanx,
jimmy

 

[walleyehed]

Re: Question For Kenny 4800 MSL lake

If they are med. brown now, I'd say thats good...they go from med brown to lite tan quick. No, I'd be happy with the med. brown.

 

[72SideWinderSS]

Re: Question For Kenny 4800 MSL lake

Just wanted to thank you Kenny for your help.
Everything worked out just fine. My Daughter, oldest Grandson and myself had a blast.

Thanx,
jimmy

 

[walleyehed]

Re: Question For Kenny 4800 MSL lake

thanks for posting back!

 

[Dhadley]

Re: Question For Kenny 4800 MSL lake

Don't ya just love it when a plan comes together?