Any help is greatly appreciated. I recently purchased a '97 Evinrude 90 HP, model # E90TSLEUA. Data tag says 1996 but everything I have researched says '97. Anyway, after first running it, it ran fine at high RPM, a little rough at idle and sounded like it might be missing a bit. After running at cruise for about 30 min, it decelerated to idle without throttle reduction. I attributed this to bad gas and took it out again on an external tank with fresh ethanol free gas. This time, after running at cruise for a bit, it dropped to idle and the engine died. Verified it has plenty of cooling, water strong out the tell tale. I decided it was time to tear into it. First performed compression check, number three cyl was low, about 65, the rest were between 85 to 87. Granted, all are a bit low but if all were close, I would have been less concerned. I decided to pull the head and at minimum, replace the head gasket. So far, this is what I have done to the motor:
Replaced CYL Head cover Gasket & Head Gasket
New Plugs with OEM Champion QL82C
New CYL head hose, old was cracked and had hole in it
New water pump assy (not just impeller)
Rebuilt both carbs, including soak and ran safety wire through all passages/jets. Used OEM kits.
I did notice a bit of play on the piston at TDC when moving back and forth by hand on the #3 cyl, probably needs new rings but didn't see any broken rings. Also noted the existence of the cross hatch pattern in both cylinders which would lead me to believe previous owner(s) may have re-ringed already.
Once everything was back together, took it out, engine starts fine and runs in neutral ok when slightly advancing the throttle but when pulling back to the neutral detent and trying to shift into gear the engine dies. Engine runs perfect from 1/2 throttle to WOT with no vibration. Also noticed on first trip out, it seemed to use an excessive amount of fuel, when compared to other motors I've owned. Not sure if this could be attributed to blow by in the cyl with the lower compression.
My next steps will be to sync the carbs, check the compression again and possibly increase the idle a bit to see if this helps. I also need to check the thermostats as the water coming out the tell tale seems to be about the same temp as the water I'm sitting in.
Any help with adjusting the idle would be greatly appreciated as I am unable to find a Service Manual for this engine. Also, if there is something else I should check, please chime in. Sorry for the lengthly post, just didn't want to miss anything.
Thanks All!!
Jason
Replaced CYL Head cover Gasket & Head Gasket
New Plugs with OEM Champion QL82C
New CYL head hose, old was cracked and had hole in it
New water pump assy (not just impeller)
Rebuilt both carbs, including soak and ran safety wire through all passages/jets. Used OEM kits.
I did notice a bit of play on the piston at TDC when moving back and forth by hand on the #3 cyl, probably needs new rings but didn't see any broken rings. Also noted the existence of the cross hatch pattern in both cylinders which would lead me to believe previous owner(s) may have re-ringed already.
Once everything was back together, took it out, engine starts fine and runs in neutral ok when slightly advancing the throttle but when pulling back to the neutral detent and trying to shift into gear the engine dies. Engine runs perfect from 1/2 throttle to WOT with no vibration. Also noticed on first trip out, it seemed to use an excessive amount of fuel, when compared to other motors I've owned. Not sure if this could be attributed to blow by in the cyl with the lower compression.
My next steps will be to sync the carbs, check the compression again and possibly increase the idle a bit to see if this helps. I also need to check the thermostats as the water coming out the tell tale seems to be about the same temp as the water I'm sitting in.
Any help with adjusting the idle would be greatly appreciated as I am unable to find a Service Manual for this engine. Also, if there is something else I should check, please chime in. Sorry for the lengthly post, just didn't want to miss anything.
Thanks All!!
Jason