87 70 johnson problems

[carrs57]

Hello all, <br /><br />My friend and I have an 87 johnson 70 giving me headaches. Just started with this boat got it cleaned up, flushed and new fluids in it, fired it up in the yard and had no apparent problems. Took The boat out to the lake, it started fine and got to a good clip until about a mile out were it started bogging down and slowly died. tried to restart with no luck. pull cover to look at the carb and gas was dripping out the front of the bore, disconnected fuel line let it sit and was able to limp back to the dock. <br /><br />today I tore the carbs off suspecting float problems but the needles/floats jets all seem good. I soaked them anyway and reinstalled. On first try after pumping the primer bulb, fuel mixture came pooring out the bottom carb and a short hose coming from below the bottom carb.<br /><br />I am new to OBs but fairly experienced mechanic. Please help point me in the right direction<br /><br />thank you

 

[Goodoleboy]

Re: 87 70 johnson problems

Hello 57...welcome to the forum!<br /><br />Your needle and seat is not closeing. Gota take it apart again.<br /><br />I would put new carb kits in all three. Remove all welch plugs soak in carb cleaner and use compressed air to make sure all crud is cleared from passages.<br /><br />Check all hoses from tank all the way to carbs. for cracks make sure all clamps are tight.<br />Pull on em wiggle jiggle look at hoses bottom and top.<br /><br />Do a compression check just so you know its ok their, write it down for later reference.<br /> <br />Check and make sure timeing is where it should be acording to specks in manual.<br /><br />If motor has bein setting in storage for a while I would replace water pump. Those impelers will become dry and brittle, And start to brake up into peices may clog water passages, Then heap big problems.<br /><br />Good luck!<br /><br />Good luck!

 

[carrs57]

Re: 87 70 johnson problems

Hello again guys,<br /><br />got a chance to work on the boat again, rebuilt the carbs, checked for 7/16 spark(no problem), and checked compresion. #1,3 = 120lbs and 2 is at 105lbs. The carbs arn't flooding out but there is still a small puddle that forms at the front of the throat. It is still miss firing really bad, removing the #2 wire has no effect as well as blocking the #2 carb of has no effect. Spraying premix into the 2 carb has no effect also. I am going to try decabing with some deep creap since that is mentioned often. <br /><br />Please help me out I'm not sure were to go from there.<br /><br />thanks

 

[carrs57]

Re: 87 70 johnson problems

Tried the seafoam and it seamed to smooth it out a pretty good but number 2 is still dead. Just for fun I tried physical chainging locations of coils and carbs but no change with either.<br /><br />any ideas? please, pretty please<br /><br />thanks

 

[kevin88]

Re: 87 70 johnson problems

Your power pack could be DOA. Do a search on this forum for power pack tests or consult your book.<br /><br />If your power pack is bad try to find the cause. <br />It could have been blown by <br />1) a bad rectifier<br />2) a bad ignintion coil<br />3) broken spark plug wire<br />4) rusty connection at the spark plug<br />or 5) a very bad set of plugs (not likely)<br /><br />remember if you replace your power pack without finding the cause for it's failure you're chances of blowing that new pack are almost 100% (taken from experience).

 

[Goodoleboy]

Re: 87 70 johnson problems

I would try switchin carbs. from one place to the other. Just to see if num.2 has a carb. problem or an electrical prob.<br /><br />Good luck!

 

[carrs57]

Re: 87 70 johnson problems

Yea I tried moving 1 to 2 = same, and then 3 to 2 = same. <br /><br />I did replace a rectifer with a burt wire when I first got it, but I would think that the power pack is eliminated due to the good spark??<br /> no?<br />what would be the best test I looked through the first couple pages of search results but found nothing for a test.<br /><br />thanks

 

[kevin88]

Re: 87 70 johnson problems

After re-reading this entire thread I found where you stated, "It is still miss firing really bad." Maybe this is where you should be looking. A miss fire can only be caused by an improperly jetted carburator or incorect ignition timing. Usuaully incorrect ignition timing will cause carbs to flood. Your ignition timing is advanced mechanically on this motor by linkage that's hooked to your throttle control. This advances the timing by moving the timing trigger assembly under your flywheel when you push the throttle forward. Check the linkage to make sure something didn't come apart on you while you were out on the lake (first post).