1979 100hp johnson

[bigbadchevy89]

I just purchased a 100 hp jounson on a 16ft 1969 glasstron its hull is inbetween a vhall and a tri hall any recomendations on what pitch prop to run? the prop that was on there was stolen while the boat was forsale.

 

[bigbadchevy89]

Re: 1979 100hp johnson

i jut found out glasstron called this hull the aqua lift 2

 

[walleyehed]

Re: 1979 100hp johnson

didn't know they had a 100hp in 79 but I would try and borrow a 19P and try it. It's a V4, we want about 5800RPM at WOT regardless of HP.

 

[bigbadchevy89]

Re: 1979 100hp johnson

thanx

 

[bassman_n44]

Re: 1979 100hp johnson

The operation range of all 100-140hp crossflow V4 E/J is 5000-5500rpm. Is it good to run it so high. Wouldn't it be wise if you were running 5800rpm to go up 2 pitch and drop rpm's to 5400?

 

[walleyehed]

Re: 1979 100hp johnson

Absolutely not...<br />when that engine was built, it was designed to run on the fuel of that era...we don't have 1979 quality fuel anymore and we've found it best to run any of the crossflow V4's-ALL of them- at 5800 for best engine life, economy and over-all performance.<br />5400 for a V4 is close to lugging.

 

[bassman_n44]

Re: 1979 100hp johnson

Does that include my 1993 115 Evinrude because it calls for 5000-5500 and I allways have run at 5400.

 

[walleyehed]

Re: 1979 100hp johnson

If it's a 90 degree crossflow, yes..If it's a 60 degree looper, No, 6000RPM is target for the looper V4.<br />OEM service material says 4500-5500, and the HP is taken at 5000.<br />5500RPM would be the lowest RPM you want with a normal load.<br />Remember, a 1993 is 13 yr old technology....we don't have the quality of fuel we had even 2 years ago, and we're talking a carbed engine running on needle, roller and ball bearings...your reeds will keep it from going over 6400-6500 anyway...it's just an air pump.<br />Dhadley may jump in on this tomorrow and add some detailed info as to why we do this, and what happens when we run lower RPM.<br />I have cylinderhead temp and fuel flow on my crossflow, and I have proof of my own of what a lugging engine does.

 

[bigNATE®]

Re: 1979 100hp johnson

well me and D.C. (bigbadchevy89) went up to Erie Prop Service today and the guy that runs the place suggested a 13¼"X17" so he decided to get it, I think he got a good deal on it too...<br /><br /><br />Dont let D.C. fool ya, he just dosent want to admit tearing up a prop (of unknown size) on his new motor <br />

<br /><br />hopefully we can get the boat on the water tonite and stick my tach on it and figure out where we need to go from there as far as pitch goes... the guy at Erie said he will repitch it if necessary for $10 so we should be able to dial it in now<br /><br />~Nate

 

[bigbadchevy89]

Re: 1979 100hp johnson

ok so nates right i was embased but neways we bent the propshaft any sugestions as where i may find this part also how hard is this to install