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jack plate for 150HP Johnson

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Hey. i have a 379T Javelin with a 150HP Johnson. I am looking for a manual jack plate and found this oneÑ

 

https://www.ebay.com/itm/Jack-Plate-JPL-4500-Adjustable-6-Outboard-Boat-Jackplate-/290875834239

 

any comments about it? or another jack plate you recommend that wont break the bank?

 

Also, can i use a 6" jack plate with my current setup without having to extend steering lines? I am running a hoot foot as well. 

 

Thank you, 

 

 

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Sounds like a deal to me 😉

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379T Javelin bass boat is 19' with 150hp Johnson so what are your goals adding a 6" jack plate?

I believe the 379T's last production model was in '94 or 24 years ago making the OB an older engine with lots of run hours and could be tired. I would check your transom strength before adding the increased stress of a jack plate.

Way2Slow has a lot of experience with your OB, maybe he will add some good input for you.

 

Tom

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thanx! 

 

my goal is better speed and performance. as it is right now, i need a hydrofoil for it to plane. it jumps on plane very quickly with one, but without the hydrofoil, it takes forever.... and my top end speed is 52 mph, when i have seen others with my same boat running mid 60s...

 

now that you mention, i rarely go faster than 40, as the lake i normally fish i can go from one end to the other in 5-7 minutes at 40 mph.... there are some bigger lakes i visit once or twice a year, and thats when i need more speed.... also i dont tournament fish... so, maybe i should not go in the hassle of a jack plate??

 

my boat is from 1994 BTW, and i am running a Raker 24 pitch SS prop. 

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Change to a 4 blade prop and get rid of the hydrofoil. Jack plate isn't going to help getting on a plane because your boat I maybe under powered. Check your engine compression you maybe better off putting money into tunning then a jack plate.

Tom

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thanx, i will check compression. i have been running this boat for 3 years now without an issue, but i know its a very old motor that may need some care. 

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Actually, I wasn't going to get into this because jack plates and not that magic bullet that many people seem to think they are.

A jack plate alone is probably not going to make a big difference in hole shot or speed.  They primarily help optimize performance once you get it close.  Getting it close means making sure the engine is at peak performance.  Making sure weight distribution is good.  Making sure the hull is good, no hooks, or high/low spots, and the boat has not been left sitting out in the rain a lot over the years and flotation foam is saturated, if it's early enough to have open cell foam in it.  Not sure when Stratos changed over to closed cell foam. 

Then there's the prop, because good SS props are pretty dang expensive, and sometimes it can take trying several different ones to find just the right one, most people are not willing to put forth the money or effort required to find the perfect prop and perfect setting that a jack plate is intended to do. Once you find that near perfect prop, and everything else is good to go, then you add a jack plate to finish tuning the setup. 

If the motor is not turning near 5,600 rpm, (5,500 is by the book but I prefer a little over spin) with your normal load, you need to work on that before first.  If it can't turn at least a 23" Raker, don't waste your money on a jack plate.  All they really do for a slow boat is get the motor up for a little more clearance in shallow water, unless you can't get it up where the cav plate is a fraction above the pad with just the motor mount bolts. Normally, you can get enough height just with the motor mount bolts.

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Way2slow gave you all the correct answers for that engine.  I would start by having the engine checked out by having the compression tested.  Forgive me, I am a Merc guy, but if your engine has a diaphragm in the fuel lift pump, I would have it replaced. I might even have new spark plugs and wires installed. Next, I would have some basic preventative maintenance done. I would replace any old fuel filters and fuel lines replaced.  There has been lots of trouble with the inside of the older fuel lines deteriorating due to the damage the new fuels can cause. I would have the prop removed and have my prop inspected and touched up if there were any nicks or dings in it. A good prop shop can inspect the hub for any signs or deterioration and replace it as needed.  This is also a good time to have your water pump replaced and the seals in the lower unit inspected.  Replace if any issue is visible or there is signs of water in the lower unit's oil when it is drained.

Measure your prop to pad and see where it is.  Also before you do anything go run the boat and record you max rpm and top speed (by GPS not speedo)  Give that info to your prop shop. They might suggest adding some cup if that would help your holeshot.  Now if that is all good you may see a benefit to your boat's performance by adding the jackplate.  To answer your original question is the Vance plate any good, the answer is yes they make a nice product. I am about to add one to my boat. Vance is a smaller company but you can order directly from them or apparently on Amazon. If you are concerned about the length of you cables you could easily consider the 4 inch version they make. That is the one I am going to add to my Lowe Stinger 170.  Vance does very little advertising, so they do not need to pay for a major ad campaign. There factory is in lower central Tennessee and they make a nice product.

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The boat is 19' powered by a tired 150 hp Johnson and depending which engine the Op has, it that can be upgraded to add about 50 hp with tunning and bolt on components. Adding a Jack plate is a waste of money and effort IMO.

Way2Slow is the sites Johnson engine expert, I only know Merc's and a some things about fast boats having owned them and raced them.

Tom

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Engine Expert???  I'm ok with some of them but I know OMC's pretty good because I've built an modified them for the past 25 years.  I'm best with the 90 degree V-6 loopers.  I can very easily take a 200/225 or 250hp and get 300hp out of those, and a lot more than that out of the 3.3/3.4.

The motor the OP has in the 60 degree Eagle series block they used for the 150hp and 175hp starting about 1992, and those are not really worth what it would cost the have one modified.  The exhaust chest on those is so restrictive, about the most you can get out of one is a little over 200hp without some radical rework.  Even 200hp requires some extensive port work that would be expensive and the motors just don't have the CC's/CI's to make good torque to launch a heavy bass boat.  You will spend a whole bunch of money and still not be very happy at the end.  I've got a 1996 model sitting on a stand now I recently  built for my son.  I did all the port cleanup and matching, and made changes to a couple of the angles, probably about 20 hours of work with a die grinder (but didn't change any port heights so as not to affect hole shot) and put a set of 175 carbs on it, and it might make 190-200hp, but that's probably being very liberal with the estimate to make him feel good.  To pay one of the few that know how to make these mods would make it cost way more than it would be prudent to spend.

A lot less money could be spent on boat setup, hull prep and prop work and see about as much performance gain.  I gained eight miles per hour out of an old 285 PRO I once had, just blue printing the hull and working on the setup (props, setback, engine height etc). That's way more than just going in a doing some average engine mods would have given.

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Johnson (OMC) engine expert and you just proved it!

Agree the hull needs to be dry and planing surface flat and true to start with. Engine height isn't easy to adjust after mounting holes have been drilled, should be checked for a baseline. The weight distribution of weight is free. Take everything out of the boat and run it to verify top speed as is. Bass boats shouldn't need a hydrofoil to get a good hole shot and that is what got my attention.

Keith, thank you adding your expertise.

Tom

 

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I'd start with the prop...Send it off to get repaired, blueprinted, and balanced.  The first time I did this I was amazed, it was like I had a different boat. Better holeshot, top end, and overall handling/responsiveness.  Should be around $300, many good prop guys but I recommend Mark Croxton - His site is easy to find. 

 

If your prop is dull and/or has any visible knicks, dings, or imperfections then it's hurting your performance.

 

Plenty of good advice here already, but if it were my boat and money I'd start with the prop...It's the single biggest factor in overall boat performance.  

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thanx for your input! 

 

i live in Mexico though, so we dont have any prop shops around. So i will start by checking compression and changing spark plugs and wires and go from there. Overall i am happy with the boat, i have fished out of it almost every weekend for the 3 years i have owned it. the requirement for a hydrofoil is what had me thinking maybe a jack plate was required for the boat to perform better. 

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plug wires may be bonded into coils and not changeable, but if the are, I would be hesitant about changing them.  It's not often they give a problem.  You CAN NOT use regular automobile plug wires

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thanx, i will change just the plugs then. In case i find the plugs locally, they will be automotive. can i use those? if not, i will have to order online in the USA and pick them up next time im up north. 

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As long a you get Champion plugs in the number it calls for, there is no problem  Normally, the only difference between marine plugs and automotive plugs is the marine plugs will usually have a stainless steel base, as long as you get the same numbers.  I guess you can order from Rock Auto Parts on line.  If you can they will have them and usually cheaper than local parts stores.

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Look up the correct spark plug numbers, don't assume what is in the engine are the right plugs.

Tom

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