7.5 gamefisher compresion

[woodsailboat]

My 1977 7.5 gamefisher still has a lot of power and will plane my 14 ft v hull jon boat with me, trolling motor, battery, 2 gallons extra fuel, cooler, tackle box, poles, and a half full live well but will not even come close to planing when I have a second person with me even when I remove every bit of gear I mentioned. So what should the compresion be on this motor since it only has one cylinder.

 

[mrcrabs]

Re: 7.5 gamefisher compresion

.5 gamefisher compresion

My 1977 7.5 gamefisher still has a lot of power and will plane my 14 ft v hull jon boat​

theres a big dif between planing and loading a vhull down so she runs as a displacment hul, move your extra person all the way forward and see if the bow comes down.

Your compression should be near to 100 psi when in fine to new condition and many Eska's are because they have had so little use for one reason or another,​

 

[JB]

Re: 7.5 gamefisher compresion

That is pretty normal for a 7.5, woody.

Don't worry about psi. It runs well, that means compression is okay.

 

[mrcrabs]

Re: 7.5 gamefisher compresion

most of the time the Eska is stuck too deep in the water and need to be raised on the transom, I added 2 inches to my last jon boat transom rebuild just to accommodate the Eska's with the F-N design...when you get them up a bit higher you will get a few more rpm out of it...closer to the spec 5650 @ WOT I have a 7.5 that I rebuilt, I bar honed the cylinder to get rid of rust and lost a good bit of compression doing so because I was stuck with a stock sized piston and stock size rings...it runs great but she don't have the grunt of solid 90-100 psi or better engine, I have a youtube of that motor pushing and one of 100+ psi Eska and you can clearly see the dif.

 

[woodsailboat]

Re: 7.5 gamefisher compresion

You see mrcrabs thats the thing, I can never get the bow up in the first place. I have tried moving the person around in the boat but there is really no difference, the bow just stays low in the water and moves like a plow. I am thinking about getting a 15 merc, yamaha, suzuki or at least something that will stand up to salt water since thats were I mostly fish. I'll just use the gamefisher for fresh water just to keep it running good and to say that I actually use it.

 

[mrcrabs]

Re: 7.5 gamefisher compresion

I feel your pain, thats why I went to the 15hp Eska built Gamefisher outboard, I have had J/E 9.9's and had merc 9.8 (weak lower unit) older mecs hate the salt, both were great motors but anyway you slice it they cost more to keep up, bigger intial investment and parts are higher cost but more avialable. Would be nice to have a new Yamaha
I'm looking for a 15hp force built Gamefisher but they'er way over priced to as far as I'm concerned.

 

[woodsailboat]

Re: 7.5 gamefisher compresion

I was about to make a deal with a guy a month ago on a 15hp force but he never called me so I could come look at it. We were going to do an even trade on my old gokart, needless to say I was pissed. Thanks for the info but I have one more question. What kind of oil do I put in the lower unit, the stuff thats still in it looks realy clean with no debris or milky looking stuff in it, but just for the future when it does need to be replaced what does it take.

 

[mrcrabs]

Re: 7.5 gamefisher compresion

80w-90w marine lube, wal-mart sells it cheap

 

[rickyrick]

Re: 7.5 gamefisher compresion

Sorry to jump in here, but how often should the oil in the lower unit be replaced? I have yet to get an manual for my 7.5, and mine is a 217-586753 model. Thanks.

 

[woodsailboat]

Re: 7.5 gamefisher compresion

You should just check it about every 5 times you use it, if you see any fileings or if it looks realy thick or milky then change it but if its clean with no debris then you should be alright.

 

[rickyrick]

Re: 7.5 gamefisher compresion

Thanks for the info, my first motor and boat so I am learning as I go.

One more thing to learn, ricky. Do not hijack someone else's thread

 

[woodsailboat]

Re: 7.5 gamefisher compresion

This forum is for asking questions and learning what people know so as long as the question is related to what the thread is about I dont think any one will mind, at least I won't mind.

 

[mrcrabs]

Re: 7.5 gamefisher compresion

Edit: woodsailboat you have changed topics in your thread so I will oblige you.

This forum is for asking questions and learning what people know so as long as the question is related to what the thread is about I dont think any one will mind

I just finished watching "Bounty" with Antony Hopkins and Daniel Day Lewis, Lots of cute native girls and it too was a story of mutany,

So Woodsailboat in case you don't know,
JB is the Moderator and Commander of this forum

best regards,
MC

 

[woodsailboat]

Re: 7.5 gamefisher compresion

OK sorry

 

[mrcrabs]

Re: 7.5 gamefisher compresion

Now you have to kiss the gunners daughter,

if you don't know what that means look it up or watch the movie LOL

 

[woodsailboat]

Re: 7.5 gamefisher compresion

Ok I guess it's only fair.