1994 Johnson 90HP lemon

[stryker]

My Johnson 90 HP motor is driving me crazy. Its the type of motor that you put into neutral by pushing the button. <br /><br />It has two problems:<br />1) Once it starts, and I engage the motor it fequently konks out.<br />2) It starts fine when its cold. I let it warm up. Then I drive it for a few minutes. Then the next time I try to start it, no luck. Then after letting it sit for an hour, it starts no problem.<br />I've tried every combination of choking it/not choking it. I make sure its getting fuel. I'm giving it gas when I start it (if I leave it at a low idle, it never starts).<br /><br />I put brand new spark plugs in twice in the last 4 weeks. I also changed the oil to Johnson oil. I don't think the gas is a problem, because it has been doing this since last year. When I pulled out the spark plugs, I did notice black cruddy deposits.<br /><br />I acquired the boat/motor used last year. I'm starting to wonder if I got a lemon...<br /><br />Any suggestions would be appreciated. I don't have the dough to bring it into a mechanic right now, so I'm trying to figure out if there is anything I can do myself.<br /><br />Thanks in advance to anyone who can help.<br /><br />- Mike

 

[seahorse5]

Re: 1994 Johnson 90HP lemon

If you have a 90 with electric shift, you have a motor that was built in 1964 or 1965. Being at least 37 years old, you might have to find a tech who is "long in the tooth" to check it out for you. Not only that, it was a troublesome engine in its day due to the bowl vent system on the 4 barreled carburetor. There were service bulletins on resetting the spark-throttle linkage and rebuilding the fuel pump, but I doubt anyone would have them handy.

 

[Tracy Coleman]

Re: 1994 Johnson 90HP lemon

M S<br />The first '64 we put on a Whaler and found that a left hand turn with a non banking boat, the fuel pickups in the 4 throat carb were on the left side and ran dry as fuel sloshed up on the right side of the carb. OMC quickly had a replacement kit to fix that problem. Your problem sounds like a bad coil. As old as it is, no telling what modifications have been made over the years. The alternator stators and flywheels have been scarce for a long time. Check the rotor, distributer cap<br />and plug wires. There was an external resister wire used on the coil, if it is still there, make sure some coil is not used with a another resister. Hard to imagine how much carbon might be in that engine, 2-3 cans of engine tuner for a start, carb cleaning and compression check. A service manual would be a must. What boat is it on?<br />Backfire

 

[DJ]

Re: 1994 Johnson 90HP lemon

Mike,<br /><br />You came out blazing with both barrels, so I'm going to give you two barrels back.<br /><br />1. You say, you put your engine in nuetral by pushing a button, that makes your engine at least 30 years old. Who knows????<br /><br />2. You DID NOT tell us a model #, serial #, nothing!<br /><br />3. You got my goat by calling it a "lemon". <br /><br />Give us more, we'll help.

 

[stryker]

Re: 1994 Johnson 90HP lemon

Wow, lots of responses... that's great. I didn't expect to get any.<br /><br />Per the title of my post, the engine is 1994 not 1964... If it were 1964 it would be a miracle that its still running I'm not sure if its a 90TL or 90TX. I'll have to look up the serial number the next time I'm at at the marina, probably Weds., and I'll look for info on whether its a TL or TX.<br /><br />I forgot to mention that the motor was rebuilt last year by the previous owner.<br /><br />Sorry if I offended by calling it a lemon! Maybe this type of operation is normal for two strokes. But if it were a car...<br /><br />tia,<br /><br />Mike