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98 Johnson fuel issue
I need some input big time on whatever issue I have going on. J225HPLEEN 98 225 ho rebuilt next size up with Wiseco pistons (I assume). Paper work doesn’t specify. Motor was under break in when I bought the boat but that’s history now. The motor idles in gear fine, cranks and idles in neutral fine. While in gear rpms around 700. Give it throttle gently and falls on its face. Give it wot all at once it bogs half a second then boom picks up and gets on plane. The hotter the day the worse it is. Early morning take offs and it runs better. But I either have to idle or be on plane, which doesn’t sound bad but in rough water not so good.
Parts changed: straight fuel pump brp, all fuel lines, plugs, stator, reeds, carbs rebuilt, jetting is my concern. I’ve read where #2 cylinder needs more fuel to keep it cooler. If I have pistons .010 bigger then factory is that enough to up jet sizes. I dunno if I have a vacuum issue or what. The last time I ran the boat the last crank up the primer bulb was empty. It was 100* degrees outside and ran its worst. The morning was 80 and ran fine. Motor cranks to easy for it to be something major it has to be something simple. If somebody gives me a suggestion that fixes my problems I will mail you $100 bucks lol.
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SC Club Moderator
Turn your idle adjust jets one full turn CCW.
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Alright. So does #2 cylinder need to be jetted different to keep that piston cooler?
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SC Club Moderator
It is a good idea to do that along with changing the carb drain plugs to the new style with the raised end on it.
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Ok is 344267the pn for the new style?
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What’s the starting point for turns out on the idle adjustment? Dumb question but the jets are a seated fit and the adjustment is made on the needle valve correct?
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SC Club Moderator
Add a 0 when ordering 0344267 order new O rings for them also 0305739. You'll need to pull out the HS orifice to get the size then go up two sizes. Orifices are fixed. Jets are adjustable. Starting point is 5 turns out from gently seated.
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Ok I’ll see how it goes thanks
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O rings and raised face plugs already on carb everything is up to date. Idle orfice is .30 and hi speed office is 74 d. I think it’s as simple as orfice change and retune. So bigger or smaller idle orfice. Or does somebody think differently
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Sprint Boats Moderator
High speed needs to be 2 sizes bigger than the rest on #2.....all the rest needs to be original.... If you're going to hammer it hard just go a little above on the oil mixture....
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Prints call for .76d on HPL models so I assume J225”HPL”EEN means I have an hpl model. With that being said should I up all the high speed orfices to 76 and make #2 cylinder a 78? Or leave em at 74 and just put a 76 in #2?
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SC Club Moderator
Leave them at 74 and up #2 to a 76
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Ok will do. What improvement if any should I see? I know it’s not going to fix my low end issue so I still have to resolve that.
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SC Club Moderator
No performance increase the orifice change simply adds a bit more fuel to the #2 piston to keep it cooler.
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Good deal thanks for the help. I’ll keep the post up to date as I tinker with it.
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Fished Rayburn this weekend and right off the trailer the motor ran great, planed quick and did what it was supposed to. The day got hot and boat wouldn’t even plane just bogged around 2200 rpm with wot, had to get a buddy to sit on the bow to break it over and then rpm’s turned up and ran like it should. Squeezed bulb while bogging and plowing and that made no difference. Bulb was hard. Held the choke in while wot and killed it instantly. Fired right back up and back to plowing. Blew it out on neutral thinking it might be loaded up and no change. So I just made my buddy get on the bow till she broke over and I got to where I wanted to go.
Any ideas? 76 orfices will be in soon and the 27’s just arrived but I haven’t swapped them with the 30’s that are in place. Mechanic told me to run 27’s for more fuel and less air. Does this sound right?
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SC Club Moderator
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Which cylinder is #2 on J225HPLEEN I can’t find a diagram to save my life.
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Sounds like I have a sibling to that engine. Just went through carb rebuilds, oriface replacement, power pack replacement with the exact issue you describe. Ended up attaching external gas tank to eliminate that variable. Is your gas tank poly or aluminum. My Hydra-sports is poly and was accumulating a lot of condensation water in the tank. Ended up installing this and it eliminated my issues:https://www.amazon.com/Moeller-Separ...a-570070090785
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It’s a poly tank and I definitely need to install a fuel water separator just haven’t got around to it yet. Thanks for the advice
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