2000 johnson 70hp starting problems

[bnelson2943]

I have been searching for the last hour for an answer but no luck. Great reading and good advice but my problem seems unique. I have twin 2000 Johnson 70 hp on my houseboat. The boat sits in the water with no use for 10 months out of the year. Thanks to this fourm, I do the recomended first of the season checklist every year. The engines have run great for several years with no problems. Last year the port side engine would not start for the longest time. I did every kind of trouble shooting I could think of but nothing. I did not have a spark tester and I wasn't sure if I was getting spark or not. New plugs, checked fuses, fresh gas, mixture sprayed into carbs, Pulled plugs and turned over engine and left plugs out to let cylinders dry out, all I could think of. I kept trying it through out the day and just as I was about to give up, the engine fired up out of the blue. It ran perfect the rest of the season and fired up with a touch of the key. It was started at least once every two days or so for the two months we used it so it never just sat for very long. I kinda of forgot about the problem until this year I went out to de-winterize and fire everything up and the same thing. Was very carful not to flood engine at the first attempts and did not apply choke or spray into carbs until after I tried to start it for awhile. Then after several hours of trying it every half hour or so, boom it fires right up. When it did fire (both years) I still had to start it several times and apply choke until the fuel system was primed enough to fuction normaly. The engine then sat for about two weeks and a friend went out at my request to see if it would start. No dice. He said he tried it many times but only over a couple hours, so I don't know if it would have eventualy had started if he would have continued trying like I had. I live several hundred miles from the boat so I can't run out and check it. I am going to have my friend go out soon with a spark tester. My question is that if it's ignition related why does it suddenly cure it's self and run fine? If it's fuel then why won't it at least cough and fire when fuel mixture is sprayed into caburetors? Can it be flooded just sitting there for a couple of weeks? What is a good test for being flooded? Sorry this is so long, it's a wierd one for me. Thanks for your help and advice.

 

[DJ]

Re: 2000 johnson 70hp starting problems

Do the spark check. Without knowing that, you're guessing.

 

[bnelson2943]

Re: 2000 johnson 70hp starting problems

I finally got my friend to go out with a spark tester. No spark on any of the three cylinders. What can cause spark not to be there one minute and then there the next?

 

[bnelson2943]

Re: 2000 johnson 70hp starting problems

After about three hours of trying the motor and running the boat up river on the other engine, it started, ran great, and would start up after that with a touch of the key. I can bet on it doing this again after it sits for awile. I'm thinking at this point what I'm dealing with is a short somewhere, possibly corrosion. Any suggestions as to where (or how) I should start looking?

 

[Silvertip]

Re: 2000 johnson 70hp starting problems

Since folks generally get "testy" when we suggest they obtain a service manual for their specific engine and then advise them to turn to the troubleshooting section (electrical in your case) and study the flow charts making the suggested checks, I will just suggest that you start by making sure the ignition and kill switch are functioning properly. Then you can move on to the CDI part of the system and make the stator and CDI tests. So now, you will need the manual in front of you for test procedures, test points, measurements etc. Or, since you have two engines, take the CDI off the good engine and try it on the balky engine. If the problem moves to the other engine, you found the problem. You might also be surprised to find that both engines now work perfectly -- which should lead you to the conclusion that connector corrosion was the issue. As for hard starting -- using starting fluid is a good way to ruin a perfectly good engine. Starting fluid has no lubricant in it so spinning the engine with no cylinder wall lubrication is a bad thing. Next, are you squeezing the primer bulb before attempting to start the engine. Doing so gets the fuel to the engine so the fuel pump can actually pump fuel to the carbs and allow the "push the key to choke" function (which is actually a primer system) to work properly. Are you using the fast idle levers properly during the start procedure. Lastly, when you boat sits for such a long period between uses, you should be using copious amounts of fuel system treatments to avoid moisture in fuel issues. Addition of a water separating fuel filter(s) is also suggested.