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1989 Evinrude 90HP V4 low speed adjustment

Z

Zubinac

New member
Model# E90TLCEM I have two diagrams I've found online, one from boats.net and one from the marine engine blog here. Boats.net diagram with my engine model number is not nearly as detailed as the other but I believe they are the same carb. Where abouts would I find the screw to adjust the slow speed/low speed?
 

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There is no slow speed fuel mixture adjustment on a 1989 model 90 HP.-----What is your motor doing / not doing ??----The trouble shooting starts with a compression test.----Post the actual values here.
 
You posted picture of say a 1969 model V-4 that did have mixture needles.----2 different carburetors shown in the above pictures.----Simple as that.
 
Thank you! Two seasons ago I acquired this motor with no history. A neighbor down the street passed away and his daughter sold off all his possession. The motor had only been registered to him for one year and never on a boat. I had a shop change out the trim motor and run through it. They did a link and sync, carb rebuild and water pump as well. They said the motor looked great and well taken care of compression numbers were 117-118 at that time. End of the first season the motor died at idle twice. In the water it would idle at 600-650 rpm and on the earmuffs on land around 1100 rpm.

This season I'm noticing more shutting off at idle about 1 in 8 times I'll stop but not right away after about 5 minutes of idle. Idle is 400-450 rpm in the water and 850-900 rpm on earmuffs on land. I double checked the notes from the shop and the timing was advanced and returned to factory when they had it.

On land on muffs it will not shut off at all only on the water. I was hoping it was something simple as the low speed adjustment. Everything else is perfect. I decarb the motor every year. And if I am near the helm I can blip the throttle a bit when I hear the idle getting a little rough and I am good for another 5 minutes.
 
Maybe look at throttle linkages and adjust idle RPM stop screw.----- Post the compression values you have today.----Is motor running with VRO in service and tested?----Or mixing at 50:1 in the tank?----Overheat horn tested ?
 
VRO motor was tested two years ago as part of that service but not since. Never tested the overheat horn. I'll do a compression test Monday when my buddy has time to come bring me his kit. Thank you guys I was looking at the carb & diagram for a good 45 minutes like an idiot trying to find the slow speed adjustment.
 
VRO pump is driven by an AIR MOTOR.-----This VRO pump has wires for a warning system.----Crankcase PRESSURE pulses drive the VRO pump.
 
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