merc 1967 9.8 on 14ft jon

[cdlegate]

i would assume that a 9.8 would have no trouble getting the boat on plane but i might be wrong. i have a 14ft flat bootom boat and i weigh about 260lbs..maybe little less and wife weighs less then me but not by a whole lot...and i have two big marine batteries in the boat right infront of where i sit in the back.. i hope that i described it enough...but if not i can upload a picture.. anyway .. any idea why it wont plane up .. i have got it up to 10mph once or twice but aveerage is 7mph (according to handheld gps) i would think that 10mph might be alittle slow for that motor..but might not be that i dont know...is there any tips and tricks or anything that i need to do to get it to plane out?

 

[fishrdan]

Re: merc 1967 9.8 on 14ft jon

Weight distribution,,, sounds like you have too much weight in the stern, outboard, you, batteries, (gas tank?). You said 14' jon boat, but then 260#, sounds heavy for a 14' jon hull unless you are counting gear.

For comparison, I have a 14' jon boat with a 7.5HP Force and the thing hauls arse, even with another adult at max load it still planes. It's loaded pretty heavy with 130# of batteries, trolling motor, 3 gallon tank, another 20-30# of misc gear,,, but the weight balanced well. The fuel tank and batteries are in the middle seat and other gear up by the bow. Only thing in the stern is the outboard, trolling motor and some light stuff.

 

[cdlegate]

Re: merc 1967 9.8 on 14ft jon

that is probly the problom when i had the wife go up to the bow of the boat it seemed to level off and the outboard wound out little more and picked up little bit of speed maybe 1mph more..so about 8mph..... ill try next time i go out to put the batteries up in my storage in the bow and my safty light weight crap in the storage i made in front of the back seat and see how that works....but i also do think the outboard isnt producing as much power as it should.. also maybe u can answer this ? or i can post it in the other forumn but i noticed that i got into a bunch of weeds as i was trolling and pulled the outboard and locked it in the up position and left the fuel line connected and next time i looked over it had been dripping gas out of the engine area since i had pulled it up...like it was still sucking gas....i assume that isnt normal...do u have any advice on that? i always thought the less weight on the bow then easier to plane the boat...but now that i think about that i can see how i am wront

 

[green4themoney]

Re: merc 1967 9.8 on 14ft jon

as long as it says mercury across the side im not concerned about anything, these 9.8's rip i have one pushing a 14 foot nalco and the thing speeds, it goes at a decent clip with my sisters husband in there as well, and hes a fat basterd 9this should accumulate for your wife, plus the 2 heavy marine batteries and any other weight you are carrying)

 

[cdlegate]

Re: merc 1967 9.8 on 14ft jon

what kind of prop setup do u have... i dont know what mine is except its a 2 blade prop...would a 3 blade prop make any difference?.. im going to try trimming it down more if its posible to see if that helps...i think 10mph is probly good for speed if i can get it there....is there any different or aftermarket props anyone would recommend

 

[green4themoney]

Re: merc 1967 9.8 on 14ft jon

i have a 2 blade on mine as well a 3 blade may give you a better thrust in the water but the 2 blade does ok... these use the old lightning blocks which is embossed on the block, these motors were totally underated in hp imho.... and very fast

 

[d.boat]

Re: merc 1967 9.8 on 14ft jon

Can you tell us how much total weight you have in the boat when it's not getting on plane? From what you wrote, it sounds like it could be nearly 600 lbs including 2 passengers, 2 batteries (large deep cycle?), fuel tank and misc. gear?

 

[fishrdan]

Re: merc 1967 9.8 on 14ft jon

Yes, how much total weight?

I've had mine loaded to the max capacity, 660# and with the hull of 130# the outboard was pushing 800#. With that it would do much better than 8MPH, probably 15+MPH. Only me in the boat it goes over 20.

And yes, try different trim positions on the outboard, makes a difference.

Also, are you sure your outboard is running right? Not sure about a Merc 9.8, but I dropped spark on 1 of my outboards cylinders (2 cylinder engine) and it ran OK, just a dog on the water,,, probably pushing 5-6MPH at the time. Just a thought.

No idea on the fuel leak, post it up on the Merc outboard board.

 

[cdlegate]

Re: merc 1967 9.8 on 14ft jon

im going to do some checking and see on spark and such..... i had it out the other day moving my batteries around and one time it would reach 11mph and then i would idle down and try again and only get like 6mph...so im pretty sure i have a problom with the carb or somthing so im going to do some checking and ill get back to you guys on other idieas

 

[cdlegate]

Re: merc 1967 9.8 on 14ft jon

and for the weight..... about average of 250lbs a peice for 2 people...two marine deep cycle batteries ..the outboard and trolling motor..is basiclly it for weight..