1969 evinrude 25 horse 2 stroke won’t start

oldboat1

Fleet Admiral
Joined
Apr 3, 2002
Messages
9,612
I have pulled many flywheels.-----Never leave the nut on.-----I doubt that the " crankshaft " will go flying off as per above post.
Ah, but it can when the tension is off the puller. (enough to bruise a knuckle, anyway.) And yes, I did mean the flywheel.
 

airshot

Vice Admiral
Joined
Jul 22, 2008
Messages
5,081
Airshot... all true except for some odd reason in all my refurbs (approx 20) I can't say I ever saw strong blue sparks mostly snappy yellows which allowed my refurbs to work quite well. I'll have to check closer on the next refurb.

Maybe I have been lucky the only time I ever had bad compression to stop an engine was on a 3hp blown head gasket (middle) .
In daylight they may appear more yellowish but in lowlight they should be more bluish to have a real hot spark. Not saying a yellow spark wont run an engine, but when someone says they have a really good spark and it is white/ yellow, then it is not a really hot spark!
Years back, my company was a source for Champion spark plug co. Had more than a few talks with their engineers and have always been told to look for a blue spark in low light conditions to know for sure you had a hot spark. That has served me well in my 70 plus years of playing with gas engines..
 

Noblo88

Seaman Apprentice
Joined
Jul 2, 2014
Messages
39
I followed the video on the point stetting/tuning. And still didn’t start, went to check spark and I had spark on one of cylinders and I can’t remember if last time I checked both or not but one cylinder has no spark. I am assuming this is possibly a bad coil? Or could it be from me tuning my points?
 

Crosbyman

Vice Admiral
Joined
Nov 5, 2006
Messages
5,440
clean the suspect points with a fine emery paper and rinse with carb cleaner. check proper continuity boot to engine frame (4-8 kohms) .

check continuity while rotating the mag plate in case you have a broken wire in a bend ...or did you replace them ?
 

Attachments

  • corrosion pic from Leroy's site.jpg
    corrosion pic from Leroy's site.jpg
    8.9 KB · Views: 2
  • cracked wires.JPG
    cracked wires.JPG
    1.4 MB · Views: 1
  • plug pin.PNG
    plug pin.PNG
    21.7 KB · Views: 2
  • spark bug.PNG
    spark bug.PNG
    335.9 KB · Views: 2

airshot

Vice Admiral
Joined
Jul 22, 2008
Messages
5,081
Airshot... all true except for some odd reason in all my refurbs (approx 20) I can't say I ever saw strong blue sparks mostly snappy yellows which allowed my refurbs to work quite well. I'll have to check closer on the next refurb.

Maybe I have been lucky the only time I ever had bad compression to stop an engine was on a 3hp blown head gasket (middle) .
I agree, never had poor compression stop an engine, but have had low compression make them a real booger to get started. Many folks just put there finger over the hole and pull....yep..good compression ! Actual numbers are are easier to figure what is low and what is good.
 

Noblo88

Seaman Apprentice
Joined
Jul 2, 2014
Messages
39
Got a bad coil, bought one online today and should be here tomorrow hopefully it’s the fix. I will keep everyone updated thank you for all the help so far and helping with my lack of knowledge on these ol motors
 

Noblo88

Seaman Apprentice
Joined
Jul 2, 2014
Messages
39
Fixed the coil, points are all set to .20 on a feeler gauge and it almost starts but still doesn’t even with starter fluid. Both spark plugs have a big blue spark to them as well. Started at 1 1/2 turns out on the carb and kept moving out and still nothin all the way to 3 turns. Also anyone know what the little line from the bottom of the cylinder to the nipple on the top under the front part of the flywheel is for? I see some fluid tryin to make it’s way up that line
 

oldboat1

Fleet Admiral
Joined
Apr 3, 2002
Messages
9,612
Fixed the coil, points are all set to .20 on a feeler gauge and it almost starts but still doesn’t even with starter fluid. Both spark plugs have a big blue spark to them as well. Started at 1 1/2 turns out on the carb and kept moving out and still nothin all the way to 3 turns. Also anyone know what the little line from the bottom of the cylinder to the nipple on the top under the front part of the flywheel is for? I see some fluid tryin to make it’s way up that line
Adjusting in the wrong direction. Adjust clockwise (leaner -- less fuel, more air) 1/8 turn at a time.
 

racerone

Supreme Mariner
Joined
Dec 28, 2013
Messages
37,818
Turn throttle till it hits neutral stop.----Remove sparkplugs.------Put 6 or 7 drops of fuel in each cylinder.-----Install sparkplugs and wires.-----Pull on the recoil a few times.----What happens ???
 

Noblo88

Seaman Apprentice
Joined
Jul 2, 2014
Messages
39
Adjusting in the wrong direction. Adjust clockwise (leaner -- less fuel, more air) 1/8 turn at a time.
A lot closer that time turned over a few times but didn’t run. I think I’m going to recheck my points and then check the timing with the continuity test
 

Noblo88

Seaman Apprentice
Joined
Jul 2, 2014
Messages
39
Turn throttle till it hits neutral stop.----Remove sparkplugs.------Put 6 or 7 drops of fuel in each cylinder.-----Install sparkplugs and wires.-----Pull on the recoil a few times.----What happens ???
I’ve been doing everything at the neutral stops/start position on the twist throttle. I think I need to double check my points and timing before and then I’ll give that a shot
 

racerone

Supreme Mariner
Joined
Dec 28, 2013
Messages
37,818
You have to start doing some simple steps and orderly trouble shooting.----But I need to step aside here.
 

davidmbv

Petty Officer 2nd Class
Joined
Apr 19, 2021
Messages
134
Turn the throttle to high and try to start. My motor a 71 25hp will not start unless I give it throttle then turn it down once it starts
 
Top