E90TSLEUA 97 90HP Evinrude compression numbers

sbump52

Petty Officer 2nd Class
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Feb 5, 2008
Messages
115
Have had hard starting issues for some time. When it would start, it would run and start ok the rest of the day. Finally noticed the enricher valve had a crack. Replaced it and it was still hard to start, but did start a little easier. Got it running on the muffs and sprayed 1/2 can Seafoam through the carbs, let it sit for about 10 minutes and restarted. Let it run on high idle for about 10 minutes. Went to lake and run it wide open for a while, then stopped to fish a spot. Started back up ok, but lots of smoke on start up. It has always done this. Went to another spot and fished for a while. Would start up and die, wouldn't idle. Started on high idle and let it idle a minute on high idle. Died again. Finally got it running and in gear and headed for ramp. Today, took to lake dropped in the water and was a little hard to start, but finally got it going. Let it run on high idle a while and then tried to idle. Would idle about 30 seconds and then die. Start back up again but only with high idle. Wouldn't idle without high idle. Brought it home checked compression. As you are looking toward bow of boat, right side of engine top 95, bottom 100. Opposite side top 90, bottom 90. Looked inside cylinders and all pistons are fairly evenly coated with black carbon junk. I always run Seafoam in gas. Should I try decarb again with the rest of the Seafoam? Maybe get some Johnson tune up in a can and use the enricher valve method? Any other ideas? Plugs are clean and uniform. Couldn't tell one from the other.
 

racerone

Supreme Mariner
Joined
Dec 28, 2013
Messages
38,534
Some will argue.-------Cheapest option is to remove bypass covers to inspect pistons / rings.-------Or remove cylinder heads for an inspection.------------Mechanic in a can may not work here.----You have checked for spark on all leads ?-------------Those motors in good condition start very easily.
 

sbump52

Petty Officer 2nd Class
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Feb 5, 2008
Messages
115
Spark checker I have is lacking. I will rent one and check for spark. Maybe weak spark on 90PSI side extra carboned up? Power pack or coils?
 

racerone

Supreme Mariner
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Dec 28, 2013
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38,534
I suggest you do the inspection and trouble shooting.---------Guessing simply does not work on these motors.
 

ondarvr

Supreme Mariner
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Apr 6, 2005
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11,527
When was the last time the carbs were disassemble and cleaned?
 

sbump52

Petty Officer 2nd Class
Joined
Feb 5, 2008
Messages
115
I have had the boat since 2011. I haven't rebuilt the carbs.
 

sbump52

Petty Officer 2nd Class
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Feb 5, 2008
Messages
115
Carb job or check for good spark? The plugs were wet with fuel/oil and pistons carboned up. Possible weak spark causing hard start?
 

ondarvr

Supreme Mariner
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Apr 6, 2005
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11,527
Anything's possible until you confirm it one way or the other.
 

racerone

Supreme Mariner
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Dec 28, 2013
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38,534
On motors in that condition I often find the starter fried.------Hard starting = frustration= more cranking = fried starter= nearly impossible to start motor.----Flywheel must spin rapidly to make strong spark.
 

bob johnson

Rear Admiral
Joined
Feb 25, 2009
Messages
4,306
time to rebuild the carbs... you need to start with clean idle passages....you are not supplying much fuel to idle those motors , so just a little bit of gunk can ruin the mix.... there is a MINIMUM RPM needed to make spark..... so if you are getting good spark, you don't need to worry about the starter as the issue....
 

sbump52

Petty Officer 2nd Class
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Feb 5, 2008
Messages
115
Rebuilt carbs. Weren't too dirty but they did have some stuff where it shouldn't have been. Started in driveway ok pretty easily and let it idle a few minutes. Took to lake next day and was hard to start. Finally got started and ran it awhile wide open. Stopped to fish and when started to go to next spot, didn't want to idle. Same thing a little later. Ordered spark plugs as local autoparts don't have them. Ordered what was in it QL82YC. Tried it again today. Harder to start. Finally got to start and it seems like it is running on two cylinders. On high idle won't pick up and run and will die after a little while. Looking at plugs they do look like the drivers side aren't firing. Got a better spark checker and verified the drivers side aren't firing and they do have fuel and oil on them, the passenger side is firing and shooting a 7/16 gap but a thin yellow spark. Went to the CDI trouble shooting web site. Reading there the plugs they recommend are QL78YC not the ones I got. The ones I got were what iboats parts manual said to use. Also read where the wires were supposed to be gray inductive resistor wires. Checked the wires on my motor and they are Hypalon Ignition wire copper conductor. Are these the same or are they the wrong wires? If the plugs and wires were wrong, why did it run ok for so long? Why did it run ok last week and now this week only two cylinders fire? Checking spark and then going to the CDI web site is a little more daunting than I had hoped. Now off to try to figure out this trouble shooting manual.
 

racerone

Supreme Mariner
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Dec 28, 2013
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38,534
Have you confirmed that pistons and rings are in good condition ?---------Inspected per post # 2 or is that too much work ?
 

sbump52

Petty Officer 2nd Class
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Feb 5, 2008
Messages
115
Not that it is too much work but I don't have gaskets laying around to replace when I am done inspecting. This isn't a motor that is run every day for hours at a time. Not to sound like I am blowing off your recommendations but the motor ran well after getting it started every time. It is getting it started that is the issue. Now it won't run even when started because of losing spark. I apologize if I come off lazy and not appreciative of your help. I don't have this DVA to run these diagnostics checks. Just hoping for some practical advice from some folks that might have seen symptoms like these. If I am too much of a bother I will tear down the whole power head and just rebuild the damn thing.
 
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