Johnson '94 115 problems

[Mirko]

Model number J115TLERC. Serial number 0(Q?) 0352231. Cant tell if first number is 0 or Q.<br /><br />First of all, is this a '94?<br /><br />This motor is new to me. Just bought the boat 2 weeks ago. Owner said it had been idle for a year or so. Felt it had bad gas. Took boat to mechanic and had water pump, gear oil, plugs changed and compression tested. Everything checked out OK. Mechanic ran motor using "shop gas" and not fuel from my tank. Cost me close to $400.<br /><br />Filled tank with about 7 gallons of new gas (out of 25) then took boat and ran it in ocean. Ran well for a while but then started surging up and down in RPM's while in gear. That eventually went away. Even though I don't know much about boats, motor seems to me to be running rough now. I have since refilled the tank with another 7 gallons of new gas or so. Wanted to drain old gas but could not find suitable place to dispose of gas. Probably got a little lazy and decided to just burn off the old gas, which was something the mechanic suggested.<br /><br />I feel that I need to have the carburators cleaned. Any thoughts on that? Clean or just rebuild? Not leaning towards doing it myself. Is it very difficult? I'm a real clutz. How much can I expect to pay to have it professionally done. I keep reading that I should get a shop manual. I still have my old Johnson 9.9 hp which sits in my aluminum boat and I agree that the after-kmarket manual I got for that motor shows too many models and is too confusing. If I decide to get the factory manual, do I need Shop Manual, Owners Manual and Parts Manual? What should the rpm's be at WOT on this motor?<br /><br />Any other thought on things I should do to this boat? It's a '94 Seaswirl Striper. I'm upgrading batteries and battery cables and installing an onboard charger which I will plug into AC off my garage. Just completed adding AC outlet to the outside of my house for that purpose.<br /><br />I have some gauges that don't work now but I'll save that for another thread.<br /><br />This sure is a great site and I thank you all in advance for all your help.<br /><br />Mirko

 

[walleyehed]

Re: Johnson '94 115 problems

mirko, welcome aboard!<br /> First of all, yes, I would highly recommend the OEM manual, it will be specific to your engine.<br />To succesfully clean the carbs, an O/H would be in order. If you follow the manual it's not difficult to do, but it MUST be done correctly, and in the steps provided via manual.<br />I'm assuming your engine is a 90deg crossflow and would recommend proping to 5800 RPM with a light load and full fuel. This will allow engine RPM to be closer to wide open throttle range with more of a load in the boat-around 5500RPM loaded.<br />As for the change in RPM, at what throttle setting were you at when this occured???<br /><br />EDIT: The factory shop manual is the one you want

 

[Mirko]

Re: Johnson '94 115 problems

I think I was at 3-3500 rpm when the surging started. I don't really remember though. I can't get anywhere near 5500. I'll take it out again in the next couple of days and check it out again. I'm not too anxious to try the carb OH myself. Not real confident at this point. How much should I pay for this? I think there are two carbs. I may need a recommendation for a Johnson mechanic that can do the carb OH.<br /><br />Let me say once agian how much i am learning here. I am going through the many old pages and getting all kinds of info.<br /><br />Thanks for your help,<br /><br />Mirko

 

[walleyehed]

Re: Johnson '94 115 problems

You may have an ignition cut-out causing what you may think is a surge, and could possibly account for not getting high RPM. This being said, what IS your max RPM at this point???

 

[Mirko]

Re: Johnson '94 115 problems

I will probably take the boat out in the next couple of days, depending on the weather. I'm still trying to figure out how much I should expect to pay for a carburator over-haul or if I should attempt it myself.

 

[Cricket Too]

Re: Johnson '94 115 problems

Mirko....I have always rebuilt my own carbs but I think the last time a shop tried to sell me a carb rebuild ( 3or4 years ago) it was in the 300 dollar range, it could be different for different carbs, but maybe one of the guys here who does it for a living can give you a better idea. I had a 1991 115, ran it with no problems for 4 seasons, good motor. Good Luck.

 

[ledgefinder]

Re: Johnson '94 115 problems

Sure sounds like gummy old gas got to the carbs. Rebuild $200 to 300, maybe 200 because we're in the off-season. OMC V4 crossflows are some of the easiest carbs to clean, if you're tempted to do it yourself. <br /><br />Old gas from on-board fuel tanks is a major problem with big outboards - you really do want to clean that tank out & keep it clean. You can burn a piston & really hurt the motor that way (one cylinder will run lean & heat up).

 

[Solittle]

Re: Johnson '94 115 problems

Before you run that thing check to see if the boat has a water seperator/fuel filter in the fuel line. That should prevent more crud from getting to the carbs. Overhauling the carbs is not that difficult if you follow the factory shop manual (get parts manual as well as it has great diagrams). <br /><br />I had a shop quote me $200 for the labor plus kits to do the carbs on one of my motors (OMC V4). I decided I would rather have that $200 in my pocket. I took my time and was careful. If you decide to give it a shot yourself get back to us for further tips.<br /><br />You mentioned taking it out before you get this problem fixed. I wouldn't as if the crud in the carbs result in a lean fuel mix you can cook the motor requiring a complete rebuild.