Can't Plane - '93 Johnson 115 on Javelin 360A

Just bought this boat. <br /><br />From research this is a matched engine & boat combo made by OMC. The model # of the engine is J115TLATS and after much research found that this engine is special and matched for this boat. (That is why the Mod # doesn't look right.)<br /><br />Compression Checks:<br /> Left Top: 120#<br /> Left Bot: 115#<br /> Right Top: 100#<br /> Right Bot: 115#<br /><br />New fuel tanks & lines<br />New Plugs<br />Visual Inspection of Carbs while running WOT show good even fuel flow.<br /><br />Symptoms:<br />Hard to start; Need to try 7-10 times with key pressed in before it will run for more than 10 seconds. Can help a little by increased throttle. Once the engine is warmed up it is still very "finikey" about stalling at idle, etc.<br /><br />Hard to plane; with gear & 3 persons (apx 650#) seated driver & one person in rear seats one in bow seat, the boat will never get on plane. Engine revs to about 2500 and that is it. Move rear person to bow and it will come up after 60-90 secs. Then bring person back to rear seat and all is fine. Speed gets up to 32MPH on my GPS unit. Came with a factory 14x17 prop. Local Mech said try smaller prop. Changed to OMC 13.75x15 and the symptoms are still the same. Detect a slight miss sometimes at high RPM on plane but not bad at all.<br /><br />Took the boat back to the dealer and went on the lake with their Mech (only 400# in the boat him & I) and the performance was slightly better but still very poor hole shots. He suggested the prop change, other than that the mech says boat/motor is fine. (I suspect CYA for warranty issues.)<br /><br />Put a spark checker on each cyl. Had great spark at 20, increased gap on checker to 30 and still had good spark. Started to lose spark at a gap of between 35-40 thousanths, so I assume ignition is OK. Of course this was at idle on the garden hose.<br /><br />As it sits now, I have a $3,000 boat that my kid's john boat with an antique 18hp can blow the doors off. Any suggestions are greatly appreciated.

Re: Can't Plane - '93 Johnson 115 on Javelin 360A

Welcome!!<br /><br />Lets start at the begining. The motor is not "matched" to any certian boat. The A replaces the E in the model number because its painted an "Alternate" color. Probably dark charcoal. May be metalic even. Nothing special or different or odd about the motor.<br /><br />I'd strt with cleaning the carbs. Especially before running it anymore. That motor should fire right up using the ol 4 step start method.<br /><br />Then make sure you have frsh 87 octane fuel. Putting new gas on top of old only means you have more old gas.<br /><br />Make sure you have Champion plugs. QL77JC4's are a great choice.

Re: Can't Plane - '93 Johnson 115 on Javelin 360A

BTW -- the spark should be much stronger than that.

Re: Can't Plane - '93 Johnson 115 on Javelin 360A

With those starting issues that you explained I would steer twords a fuel issue. They may deliver good flow with the pressure of WOT, but that doesn't mean they are up to par when it comes to starting, low idle, etc.

Re: Can't Plane - '93 Johnson 115 on Javelin 360A

Thanks for the quick reply!<br /><br />According to the former Javelin engineer I spoke to on the phone the boat was designed around the engine and the model # on the engine is different because of that.<br /><br />I have new Champion QL77JC4's installed.<br /><br />Don't know what the "4 step start" method is. Please explain.<br /><br />New fuel lines, tank and BP Premium 91 octane gas. (The only stuff we can get around here without Ethanol in it.)<br /><br />

Originally posted by Dhadley:<br /> Welcome!!<br /><br />Lets start at the begining. The motor is not "matched" to any certian boat. The A replaces the E in the model number because its painted an "Alternate" color. Probably dark charcoal. May be metalic even. Nothing special or different or odd about the motor.<br /><br />I'd strt with cleaning the carbs. Especially before running it anymore. That motor should fire right up using the ol 4 step start method.<br /><br />Then make sure you have frsh 87 octane fuel. Putting new gas on top of old only means you have more old gas.<br /><br />Make sure you have Champion plugs. QL77JC4's are a great choice.

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Re: Can't Plane - '93 Johnson 115 on Javelin 360A

Update:<br /><br />Had a mechanic friend stop by and we started tinkering. Hooked up a timing light and found the timing at idle, on the garden hose, to be at 4 degrees and the timing screw was extended to within 4 threads of the bitter end.<br /><br />Adjusted the screw to about the middle and checked timing again and read 20 degrees. Dropped her in the water and the performance was remarkably better! Pulled out of hte hole in under 40 seconds and I didn't have to have the passenger jump into the bow, and WOT speed jumpped to 38MPH on the 13.75x15 prop. Also most of the starting and idle problems went away... Go figure. <br /><br />Can anyone give the correct procedure for setting the timing on this beast? The label says 28 degrees, but at what RPM and should this be under load or can this be set on the hose?<br /><br />Also found the motor is not charging. Plan on installing new rectifier/regulator today.<br /><br />So much for Link Recreation's "Guaranteed ready to run" used boat sales pitch...

Re: Can't Plane - '93 Johnson 115 on Javelin 360A

The starting method is --<br /><br />1- Pump the bulb. This pressurizes the system and fills the carbs.<br />2- Turn the key to the "On" position. Do NOT engage the starter. <br />3- Push the key in for a 6-8 count. This allows the primer to release fuel into the intake manifold.<br />4- Turn the key to the "Start" position. The motor should start almost instantly. You may need to tap the primer as it warms up.<br /><br />You should start with cleaning the carbs first. This will work best if everything is as it should be. Running the motor with dirty carbs may cause a lean condition. Pistons dont like that.<br /><br />The motor was designed to run on 87. If you must run on 91 make sure the motor is capable of at least 5800 rpm. This will help keep the combustion temps down. <br /><br />Make sure the t-stats are in and working.

Re: Can't Plane - '93 Johnson 115 on Javelin 360A

"Had a mechanic friend stop by and we started tinkering. Hooked up a timing light and found the timing at idle, on the garden hose, to be at 4 degrees and the timing screw was extended to within 4 threads of the bitter end.<br /><br />Adjusted the screw to about the middle and checked timing again and read 20 degrees. "<br />-----------------------------<br /><br />Get a manual and do that timing correctly, or you're just waiting to ruin your engine. If it is taking 40 seconds to plane that boat, it's not running properly.<br /><br />Fiddling with timing is a bad idea, unless you know exactly what you're doing. Advance it too far and you'll have serious detonation at WOT and probably hole a piston.<br /><br />From your description, it sounds like you have a weak ignition system. Your spark should be better than that. I'm guessing one cylinder is dropping out under load.<br /><br />If you get this engine running properly, the results will be more than dramatic. You'll be amazed.<br /><br />If you don't like your mechanic or marina, take it somewhere else. Fiddling's a bad idea.

Re: Can't Plane - '93 Johnson 115 on Javelin 360A

CATransplant,<br /><br />I realize that "fiddeling" can be a bad thing. I am an experienced engine mech, but do diesel. My brother-in-laws who came over to assist with the new toy are automotive & small engine mechs with about 20 years of experience. The basic concepts we have down and are well aware of the risks envolved.<br /><br />I do not have a manual yet for this engine, I am waiting for it to be delivered. The boat season is, as you know, very short up here in the frozen north so every weekend is valuable. We are attempting to diagnose and get the boat usable before we have to start plowing the snow again.<br /><br />That said; I return to my previous question of at what RPM should the timing be set, and is the proper procedure to be found somewhere online, or simple enough to express on this message board? (We only "fiddeled" to determine that the adjustment we made made a significant improvement in the performance, thereby indicating that we were looking in the right direction.)<br />---------<br />"I'm guessing one cylinder is dropping out under load."<br /><br />I checked each plug with an inductive tester at WOT during our brief test run and all 4 were firing with the engine warmed up and on plane. I didn't check during the bogged down period while trying to get on plane because of the high bow angle this boat takes when trying to get up. (Once I get the timing set properly I may try moving the pin further forward so I can trim the bow down a little better while trying to get out of the hole.)<br />-----------<br />"If you don't like your mechanic or marina, take it somewhere else. Fiddling's a bad idea."<br /><br />Every boat yard here that deals with OMC has told me that if I bring the boat in they "may" be able to get it done by end of September. So basically it is do it myself or wait until next year.<br />--------<br /><br />What would you expect the spark to be and how would you recommend I test? Where would you suggest I start looking for the cause if spark is too weak?<br /><br />Thank you for your suggestions and help.<br />--Allen

Re: Can't Plane - '93 Johnson 115 on Javelin 360A

Dhadley,<br /><br />Thanks for the description of the 4 Step. Worked like a charm and started on the first try and stayed started for once! "Use it right & it works right!"<br /><br />"You should start with cleaning the carbs first. This will work best if everything is as it should be. Running the motor with dirty carbs may cause a lean condition. Pistons dont like that."<br /><br /><br />Checked the plugs after the test run and they looked like the engine was running a little rich, if anything. Called Link Rec. and talked to the mech who checked the boat out before it was put on the salesroom floor and he swears that he did the carb as part of their routine presales setup of the boat.<br /><br />"The motor was designed to run on 87. If you must run on 91 make sure the motor is capable of at least 5800 rpm. This will help keep the combustion temps down."<br /><br />I would be more than happy to save the extra $.30 per gal on regular, but was worried about the ethanol eating seals, etc. Everything here is 10% - 15% alcohol except for Premium.<br /><br />I was under the impression that the redline for this engine was 5500 rpm.<br /><br />"Make sure the t-stats are in and working." <br /><br />Running on either lake water @ 65 degrees or the garden hose at about 48 degrees the water coming off the "pee" hole warms up within a couple of min and gets quite warm. Will put a thermometer on it next time I run. <br /><br />I did have (what I presume) was an OT alarm (continous alarm signal) once on the lake when some of the intakes got clogged with weed junk. Cleared them and the alarm went away in a few seconds. Until I get the repair manual I do not even know where the thermostats are, so I can't be more scientific about them.<br /><br />Thank you very much for your assistance.<br /><br />--Allen