1989 140 hp evinrude wont reach wot

**savae123** · 06-28-2016, 03:52 AM

I have a 1989 140 Evinrude that will only reach W OT if you take the airbox is off I know I can't run it this way and I'm at a loss as to what is going on with the airbox is off the motor spool up right to 6000 I have all new coils good Champion Spark Plug's there are new also timing is set to factory specs underload I've tried 1315 and 17 pitch props and nothing helps except taken off the air boxes I found out they have 50 intermediate jets and are supposed to be 54s I have the 54s on the way but in the meantime wanted to shake some brains and see if somebody could tell me what simple little thing I'm missing that's causing this problem thank you I didn't mention that there are two of them on the boat both have same problem

**racer** · 06-28-2016, 10:08 AM

Did this just start? What size are the mains? Is the baffle in the air box? Timing linkage moving as it should?

**savae123** · 06-28-2016, 11:03 AM

Mains are63 d timing linkage seems ok i bought the boat this way old owners said top speed was 25 mph and i knew that wasn't right . I did replace the vro fuel pumps with manual ones also i just know its something simple that im missing yes baffles are there

**flabum1017** · 06-28-2016, 05:48 PM

try putting the airbox back on and running it with the cowling off...... maybe a bad powerhead gasket letting exhaust gasses in

**savae123** · 06-28-2016, 06:40 PM

Ran them for a couple hours with cowlings on with no problems only time thers a problem is if the airboxes are on

**racer** · 06-28-2016, 06:41 PM

Eating its own exhaust is possible but very rare on that engine. Dont run it without the airbox if you remove the cowl. 63D is the correct main jet, if carbs are not running over and the sync/link is good and it has spark on all 4 I would say you may have a weak stator. You need a peak reading meter to check.

**Jason Joe** · 06-28-2016, 07:47 PM

Originally Posted by savae123

I have a 1989 140 Evinrude that will only reach W OT if you take the airbox is off I know I can't run it this way and I'm at a loss as to what is going on with the airbox is off the motor spool up right to 6000 I have all new coils good Champion Spark Plug's there are new also timing is set to factory specs underload I've tried 1315 and 17 pitch props and nothing helps except taken off the air boxes I found out they have 50 intermediate jets and are supposed to be 54s I have the 54s on the way but in the meantime wanted to shake some brains and see if somebody could tell me what simple little thing I'm missing that's causing this problem thank you I didn't mention that there are two of them on the boat both have same problem

If you haven't already checked them you might make sure all high speed jets are tight. Also might verify I.D. of jets if high hour motors. Are these engines used at altitude or sea level?