Really need some advice!!!

[RCurry2069]

Ok, here's the deal - i have a nissan 1542 semi v that i really like. I bought it in march for 650$ and it came with a decent trailer and a 1976 model johnson 25hp ele start. The motor needs work (points under the flywheel are screwed up) so i bought another motor from a friend. Its a 1992 johnson 15 that runs real good so ive been fishing every weekend since i got it.

My problem is this - the boat sits very low in the water in the back. When i'm running wide open, water actually seeps in over the edge that i sit on. I know it is much heavier in the back with the motor, battery, gas tank, and me back there (i'm about 240) but the front end sits pretty high out of the water - almost like it doesnt plane out at full speed. Im not sure my motor isn't strong enough to plane the boat out or what. I always put my cooler on the opposite side of me to try to balance the boat out, but it doesn't help that much....

Any ideas?? Ive had a few boats in the past, but never had a jon boat before - all ski boats. If yall have any ideas i sure would appreciate it bc i just dont know what to do

 

[linehand]

Do you have room to move your fuel and battery towards the bow?

 

[Dragonman]

Can you change the angle of your motor?

 

[FuzzyGrub]

It sounds like you have a modified v jon boat (described as semi-v jon), but wasn't aware Nissan made any.

If you are on plane, the boat should be level and skimming over the top of the water.

I agree with linehand, move what you can, as far forward as you can. At least for a test. Even add some weight forward for testing.

No miss match of transom height with engine shaft? Have you expiermented with trim positions?

 

[RCurry2069]

now that is with the motor trimmed all the way down. Picking it up a couple of clicks would probably raise the front end more and drop the back wouldn't it??

If i moved the tank and battery forward, id have to extend the fuel lines and wiring (which i guess wouldn't be a big deal) but i don't have any way to conceal / hide them so theyd probably be in the way

I have a pedestal seat in between the bow and middle bench. Even when i have someone in that seat to even the weight out, it is stills very low in the back.

 

[FuzzyGrub]

now that is with the motor trimmed all the way down. Picking it up a couple of clicks would probably raise the front end more and drop the back wouldn't it??

Only while getting on plane. Once on plane, boat should be rather level. Are you getting on plane? All the way in, usually has the prop pointed downward. Try a position where the prop shaft is parrellel to the boat bottom.


If i moved the tank and battery forward, id have to extend the fuel lines and wiring (which i guess wouldn't be a big deal) but i don't have any way to conceal / hide them so theyd probably be in the way

I would do it, to see it fixes the issue. Don't have to hook up the battery to test, and gas line is cheap. Not allot of other choices, weld on pods, or go on severe diet. PS: I'm 270 guy, myself.


I have a pedestal seat in between the bow and middle bench. Even when i have someone in that seat to even the weight out, it is stills very low in the back.

How about if they sit in the bow?

See above.

 

[RCurry2069]

now that is with the motor trimmed all the way down. Picking it up a couple of clicks would probably raise the front end more and drop the back wouldn't it??

Only while getting on plane. Once on plane, boat should be rather level. Are you getting on plane? All the way in, usually has the prop pointed downward. Try a position where the prop shaft is parrellel to the boat bottom.


If i moved the tank and battery forward, id have to extend the fuel lines and wiring (which i guess wouldn't be a big deal) but i don't have any way to conceal / hide them so theyd probably be in the way

I would do it, to see it fixes the issue. Don't have to hook up the battery to test, and gas line is cheap. Not allot of other choices, weld on pods, or go on severe diet. PS: I'm 270 guy, myself.


I have a pedestal seat in between the bow and middle bench. Even when i have someone in that seat to even the weight out, it is stills very low in the back.

How about if they sit in the bow?

See above.

If they sit on the bow it does help.
Its not getting on plane like it should. I do have the pin all the way down, so maybe leveling the motor instead of being a little down will help?? Ill try that this weekend (next opportunity to use boat due to alot of working), as well as moving the battery and fuel tank.

So yall dont think its a hp problem?? If so thats good to know, i was wondering if the 15 just didn't have enough power to plane it out. If not i guess i just need to see about fixing the 25

 

[Ranchero50]

Might be a little low on power and moving the weight will help alot. How is the boat rigged, any wood or other heavy structure? Can you pick the boat up off the trailer? I wouldn't be afraid to run a can of carb cleaner through the engine and make sure the fuel to oil ratio is right on. Run it a bit heavy on the oil and it'll be a pig too. Doo a wide open throttle run for about 30 seconds and electrically shut it off while wide open. Then check the plugs to see if it's running too rich.

Jamie

 

[FuzzyGrub]

I'd think a 15 should get you on plane, unless as jamie asked, you have allot of weight in deck, etc. Maybe it is over propped so you can't get enough of the powerband to get on plane.

A 25hp would be much better though, and I would start working on it.

 

[richg99]

You might try one or two five gallon buckets of water...with lids on, of course...tied down near the bow. Be sure they are tied in securely. You don't want them moving around when you are trying to get up on plane.

If the bow comes down....then moving the weight forward will help even more. ( i.e. you lose weight in the stern and gain it in the bow). Water weighs nearly 8 lbs per gallon. One battery weighs near 55 lbs.

Smart Tabs would help a lot on getting her up on plane, if you have sufficient hp. One guy on this group built his own version of them. I am not a fan of "dole fins" or other add-ons that can slow a boat down, but some people swear by them. Better than nothing, I believe. regards, Rich

 

[RCurry2069]

No deck at all. Its pretty much just a bare boat - middle bench, halfway livewell, and thats it

I thought about adding a small deck on the front so it would weigh it down a little...

ill do some experimenting this weekend and let yall know - thank yall very much for your advice!!

 

[RCurry2069]

You might try one or two five gallon buckets of water...with lids on, of course...tied down near the bow. Be sure they are tied in securely. You don't want them moving around when you are trying to get up on plane.

If the bow comes down....then moving the weight forward will help even more. ( i.e. you lose weight in the stern and gain it in the bow). Water weighs nearly 8 lbs per gallon. One battery weighs near 55 lbs.

Smart Tabs would help a lot on getting her up on plane, if you have sufficient hp. One guy on this group built his own version of them. I am not a fan of "dole fins" or other add-ons that can slow a boat down, but some people swear by them. Better than nothing, I believe. regards, Rich

What is smart tabs??

 

[RCurry2069]

Might be a little low on power and moving the weight will help alot. How is the boat rigged, any wood or other heavy structure? Can you pick the boat up off the trailer? I wouldn't be afraid to run a can of carb cleaner through the engine and make sure the fuel to oil ratio is right on. Run it a bit heavy on the oil and it'll be a pig too. Doo a wide open throttle run for about 30 seconds and electrically shut it off while wide open. Then check the plugs to see if it's running too rich.

Jamie

The motor runs really good - no loss of performance

 

[chavist93]

If you are not concerned about possibly losing a couple mph, a hydrofoil should bring the bow down for you.

 

[FuzzyGrub]

What is smart tabs??

https://www.nauticusinc.com/smart_tabs.htm

I use them on my i/o and very happy with them. Quicker planing, less bow rise, reduced v bow wonder, and no high speed porposing. Also have them on my 14' Starcraft mod V (not a jon).

My experience with a Stingray jr (foil) on that same starcraft/40hp nissan, was disappointing. While it did provide lift and little quicker plane time, the loss of high speed and handling issues, with too much stearn lift after being on plane (no trim adj). I've seen others have similiar issues, but others are very happy with them.

 

[flatboat]

wow i didn't know nissan made boats . i'm not really a fan of stuff on the cavitation plate , if outboard makers thought there was a problem with a boat planing they would put a bigger plate on it . jmo. i think you might be underpowered , might be askin' a little to much outta 15 hp .. empty it might plane with the gas tank moved forward . thats kinda big boat . might be a prop issue . sometimes people try to run a little to much pitch thikin i't will run faster . small motors are real tricky to get everything balanced. just try movin stuff forward and see how it works . don't have to make it permanate till you figure what works . good luck keep us informed how it runs .

 

[richg99]

Just go to the Smart Tabs site as recomended above

https://www.nauticusinc.com/smart_tabs.htm

and watch the

SMART TABS Comparison Video

That should answer most of your questions. I have them on my 16 CS right now, and have added them to three of my last four boats.
regards, Rich

 

[RCurry2069]

Looks like raising the pin 2 notches and relocating the battery and tank did help alot!! It is still not quite to plane, but it is close enough for me till if fix the 25hp. How hard is it to fix the points under the flywheel???

 

[Ranchero50]

Points under a flywheel can be a PITA when the flywheel doesn't want to come off. A decent steering wheel puller should get it to release though.

On my old IO I made my own hydrofoil out of 1/8" aluminum and bolted it to the cav plate. Made a world of difference in planing as said above. I don't understand why they make them formed like wings though, water doesn't compress like air...

Jamie