1985 evinrude 150xp

J

joe agey

Seaman Apprentice
Joined
Oct 11, 2011
Messages
34
I have a 1985 evinrude 150xp will not push boat through the water very fast however it will go about 15mph at full throttle and the compression on the motor is from left to right read left top 95 left middle 90 left bottom 95 right top 90 right middle 95 right bottom 90 so with all that said what should the compression be
or what is a good compression supposed to read?

confused: joe agey
 
B

boobie

Supreme Mariner
Joined
Nov 5, 2009
Messages
20,826
Re: 1985 evinrude 150xp

First off do a good decarb on it. Then do a cyl drop test on it to see which cyls aren't firing.
 
J

joe agey

Seaman Apprentice
Joined
Oct 11, 2011
Messages
34
Re: 1985 evinrude 150xp

boobie said:
First off do a good decarb on it. Then do a cyl drop test on it to see which cyls aren't firing.
Click to expand...

did the drop test on the motor and cylinder 4 and 6 did not make a difference in the way the motor ran. The plugs all have a spark on them.

joe
 
E

emdsapmgr

Supreme Mariner
Joined
Dec 9, 2005
Messages
11,551
Re: 1985 evinrude 150xp

The compression readings are close to normal for that engine. 95 is probably a good figure, but yours are all very close. They seem fairly consistent with each other-within 10 lbs-another good sign. Possible that the engine is not running on all 6 cylinders. When you have the engine under load, remove the cowling. Put an inductive timing light on all 6 plugwires. The flashes in the gun will show you the quality of spark to each plug. It will show misfires, weak firing.
 
J

joe agey

Seaman Apprentice
Joined
Oct 11, 2011
Messages
34
Re: 1985 evinrude 150xp

emdsapmgr said:
The compression readings are close to normal for that engine. 95 is probably a good figure, but yours are all very close. They seem fairly consistent with each other-within 10 lbs-another good sign. Possible that the engine is not running on all 6 cylinders. When you have the engine under load, remove the cowling. Put an inductive timing light on all 6 plugwires. The flashes in the gun will show you the quality of spark to each plug. It will show misfires, weak firing.
Click to expand...

I put the timing light on all six plug wires and the timing light was good on all six plugs. I also checked the timing on the engine and the second cylinder mark was at the timing mark. I need to know how to set the timing on the engine and what the timing should be. and the rpm gauge was reading 2400 rpm. the rpm gauge when first crank up started at about 1900rpm and after the engine warm up the gauge when up to 2400rpm.

thanks, joe
 
E

emdsapmgr

Supreme Mariner
Joined
Dec 9, 2005
Messages
11,551
Re: 1985 evinrude 150xp

If cyls #4/6 wires are getting spark, but make no difference when the wires are disconnected-that's a sign the plugs are not firing. Are the wires shorting to ground? Run the engine at night and check for spark-when it's dark and you can easily see if it is jumping to ground. Have you checked to make sure they are getting fuel through those carb throats? What do the plugs look like when you compare #4/6 to the others after running? Are they wet or dry-what color do they appear to be?.
 
J

joe agey

Seaman Apprentice
Joined
Oct 11, 2011
Messages
34
Re: 1985 evinrude 150xp

check the wires and there was a ark at the powerpack from the ground wire to the ignition coil wires on the left side of motor cyls 2/4/6 move the ground wire and that fix the ark problem. The plugs are all wet and the end of the plugs are black with no buildup on them.
 
E

emdsapmgr

Supreme Mariner
Joined
Dec 9, 2005
Messages
11,551
Re: 1985 evinrude 150xp

Now that you've fixed the arcing problem, is the engine running normally on all 6 spark plugs now?
 
J

joe agey

Seaman Apprentice
Joined
Oct 11, 2011
Messages
34
Re: 1985 evinrude 150xp

the motor sound good now. need to find out what the timing is suppose to be on it the rpm gauge it start off at about 500rpm and goes up to about 2400rpm should i set the timing down on the motor so when the motor is warmup the rpm is around 500rpm.

thank you joe agey
 
E

emdsapmgr

Supreme Mariner
Joined
Dec 9, 2005
Messages
11,551
Re: 1985 evinrude 150xp

That engine's idle should be set to 650-700 rpm when it is floating normally in the lake and in forward gear. You can't set it accurately on the trailer.
 
J

joe agey

Seaman Apprentice
Joined
Oct 11, 2011
Messages
34
Re: 1985 evinrude 150xp

what do i need to turn to set the rpm on the boat motor.

joe
 
E

emdsapmgr

Supreme Mariner
Joined
Dec 9, 2005
Messages
11,551
Re: 1985 evinrude 150xp

There is a large screw on the spark advance lever. The rubber boot on the end of the screw pushes against the starboard side of the block. You will be adjusting the idle timing-nothing to do with the carbs. Screw it in for more rpm's. If you have any problems adjusting it, you may have to temporarily remove the throttle cable there at the engine end to free up the linkage while you set it. Then make a slight adjustment to the throttle cable, then reconnect it.
 
Last edited:
J

joe agey

Seaman Apprentice
Joined
Oct 11, 2011
Messages
34
Re: 1985 evinrude 150xp

I have a new question. I took the carbs 2 and 3 off today and found a small fuel line off that looked like it went into the intake below the second carb and then i found another place on the intake that looked like a fuel line went on it. it is located under the third carb on the intake. need to find a diagram on the fuel system.

thanks Joe Agey
 
E

emdsapmgr

Supreme Mariner
Joined
Dec 9, 2005
Messages
11,551
Re: 1985 evinrude 150xp

Possible you are talking about the fuel primer hose. One goes from the fuel primer solenoid to the hose barb on the top of each of the 3 carbs. That engine may also have a recirculation system on it, which will have 6 of the same size (small) hoses going to various areas on the block.
 
J

joe agey

Seaman Apprentice
Joined
Oct 11, 2011
Messages
34
Re: 1985 evinrude 150xp

now I have all the fuel lines fix. I need to find out how to set the rpm on the motor when motor warm up the rpm will go up to about 2000 rpm what do I need to look at to set the rpm.
Joe
 
J

joe agey

Seaman Apprentice
Joined
Oct 11, 2011
Messages
34
Re: 1985 evinrude 150xp

joe agey said:
now I have all the fuel lines fix. I need to find out how to set the rpm on the motor when motor warm up the rpm will go up to about 2000 rpm what do I need to look at to set the rpm. Today I am checking the check valve on the motor one of the check valve seems to be close what i mean is i can't blow or suck on it another valve i can't blow through it but if i suck on the hose gas will come through it. what i need to know is how is the check valve are
supposed to work.
joe
Click to expand...
 
E

emdsapmgr

Supreme Mariner
Joined
Dec 9, 2005
Messages
11,551
Re: 1985 evinrude 150xp

Are you working from a factory service manual? You may want to acquire one from the original publisher, Outboardbooks.com.
 
J

joe agey

Seaman Apprentice
Joined
Oct 11, 2011
Messages
34
Re: 1985 evinrude 150xp

check the check valves today and found one that was not working right. Took it off and clean it out with carb. cleaner crank the motor and the rpms was around 1000rpm so now i am fixing to replace the termostats and find out how it runs
But i need to know what the termostat cover bolt are to be tork to. thank you for all the help.
joe agey
 
J

joe agey

Seaman Apprentice
Joined
Oct 11, 2011
Messages
34
Re: 1985 evinrude 150xp

hi back again with a another question. Need to find the torque pattern on the head bolts and cover plate that is in front of the head that hole the thermostat.
joe
 
You must log in or register to reply here.
Top