'94 Johnson 225 RPM Drop

fishcanyons

Recruit
Joined
Aug 28, 2003
Messages
4
After running WOT for approx 5 minutes I drop to exactly 4750 RPM from 5500. From there I get erratic & brief "sputters" back up to 5500. Replaced original primer bulb, Racor seperator checked & OK. Don't know if this is coincidental but adjusting trim sometimes bumps it back up to 5500. Seems like it's electrical problem, any insight?
 

Reel Appeal

Chief Petty Officer
Joined
Aug 19, 2002
Messages
566
Re: '94 Johnson 225 RPM Drop

You may want to start with a compression check first.It sounds like you are losing power on a cylinder.Pull and check the spark plugs and note any differnce between them.If you find one that looks different from the rest,check/clean-out the carburator that corresponds to that cylinder.You can purchase a inline spark tester but testing will be difficult if your problem is at high speed under load.Is the motor pumping water at speed?Good luck.
 

Cricket Too

Lieutenant Commander
Joined
May 14, 2003
Messages
1,732
Re: '94 Johnson 225 RPM Drop

Same thing happenend to me. Number 5 cylinder was dying then restoring itself. It would go from 3700 rpm to about 4200 then back down. Swapped coil for that cylinder, no dice. Swapped power pack, no dice. It turned out to be the timing base, I was told this was rare and that it is usually the power pack. Good Luck.
 

albertastratos

Recruit
Joined
Sep 1, 2003
Messages
1
Re: '94 Johnson 225 RPM Drop

Wow...same thing happening to my 94 175 Intruder.<br />OMC must know something about this flaw. Coils were all changed last year.....nothing changed.Dealer cant/wont help me....is sick of seeing boat.....help
 

fishcanyons

Recruit
Joined
Aug 28, 2003
Messages
4
Re: '94 Johnson 225 RPM Drop

I appreciate the input guys. I also experienced erratic failure of the tach which sounds common with some of you too. CrazyJ, sorry to hear about your ordeal but it's extremely informative, thanks for posting the details.
 

marinegrh

Petty Officer 2nd Class
Joined
Sep 1, 2003
Messages
196
Re: '94 Johnson 225 RPM Drop

sounds like a stator, did yo check out the vac from it, and ohms, shorts to ground, tach is driven from the reg/rect, but needs a good stator to operate properly, is you timer base potting melted around the pivot point, and magnets, ah ha, id check those, people often forget those things, they tend to break, and separate from the glue, causing some funky scenerios<br /><br />good luck
 
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