1972 evinrude 125 issues

[clearwatguy]

been reading this forum a lot and you guys have already helped me a LOT!

i have an mfg 17 foot trihull open bow and it came with 2 1972 evilrude starflight 125 motors one good mounted and one with a blown piston but otherwise complete.

over the weekend i took her to the lake and fired it up with the hood off so i could check the heads for cooling... (seee? been reading this forum a LOT) well it was not cooling so i retreived and went back to the campsite and there in the woods with this forum, my blackberry and a a coleman lantern i changed the pump and took it back down the next day cooling problem solved. now problem 2 it starts and runs very well but misses and has no top end at all. when i say no top end i mean no top end... i was passed at wot by a guy and 3 kids in a flat bottom with a montgomery ward 7.5 horse seaking... this is my first boat but im thinking it should run fast enough to overtake a riddlin addicted teenager in a canoe

stats (again because i have been reading)

compression test

looking at the back of the mounted motor the right bank of cys was 140 top 135 bottom left bank 125 top 125 bottom.

spark is there on all 4 wires BUT the right bank will jump a lot further than the left bank of cyls

plugs the right bank is black oily and wetish the left bank is clean and dry...

so basically here is what i have. lower compression, weaker spark let completly clean pugs on the left side both cylanders... fouled plugs, better compression and stronger spark on the right side. i dont know if my issues are fuel, compression or spark related!

now i know i need to pull the flywheel but this is where i need help... i dont know what will work to pull the flywheel as far as a puller i was thinking probably a 3 leg 2 ton 12 inch standard puller but im not sure.

second i have no clue what to look for once i get it pulled off other than breaker point gap and coroded connections.

is the compression THAT bad? lol help me obiwan-outboarders your my only hope

 

[emdsapmgr]

Re: 1972 evinrude 125 issues

Those 125's ran very high compression due to the heads. 135/140 is normal. I would not condemn the port bank yet. If the rings are carboned up on one side, this can affect compression. I'd run a can of Bombardier Engine Tuner through the engine first, then recheck the compression again. It may come up somewhat. Not unusual for there to be some variance between the banks right out of the factory. 5-7 lbs is normal. Wet plugs indicate that the starboard side ignition may not be firing. Put an inductive timing light on all 4 plug wires when the engine is running. The light will show plugwire misfires and nofires. You can swap the two spark plug coils from one side to the other and see if the spark problem moves to the other side. If so, repl the bad coils. Likely these coils are not your problem. Also in the ignition system is the stator, a sensor coil (both under the flywheel) and the pulse pack-there are no points. These early ignition systems required a factory manual and some dated diagnositc equipment to verify ignition problems. Some Bombardier dealers may still have equipment to diagnose the problem. You could just start replacing these components, but they are expensive, so you may want to have a tech look at it for you. Another option is to swap these ignition parts one at a time with the other engine you have and check the results with the timing light as you go. I'd swap the pulse pack first-it is a prime suspect. You don't need to pull the flywheel to repl the pack.

 

[clearwatguy]

Re: 1972 evinrude 125 issues

somthing is not right here i only have 1 coil... it leads to the stator under the flywheel and it appears the plug wires come from the stator assembly as well but it DOES have a "pulse pack". i am going to try the seafoam process i found on here to decarbon the engine and ill do another compression test after. i have loads of faith in seafoam i have used it to correct issues with everything from my corvette to my lawn mower the stuff is amazing. i am going to take your advice and change out that pulse pack as well and see what i get from that (wont know till weekend its a 40 mile one way drive to somwhere i can her wet!) maybe ill take the carbs off the other motor and bag them and take them as well just in case.

 

[emdsapmgr]

Re: 1972 evinrude 125 issues

Yep, you are right-the later models have a coil for each plug. Another problem with trying to diagnose from my old memory. Having the luxury of a second engine lets you change components and see the result-without having to spend any $. What a rairty in the boat business!

 

[clearwatguy]

Re: 1972 evinrude 125 issues

update on my top end issues. i got the flywheel off with little problems took her an hour and the noise it made when it went i thought one of the bolts had broken on the puller! the rotor terminal and the brass terminals inside the cap were lightly coroded and black and nasty looking so i cleaned them all up and when i went to check the gap (according to my book and the top of the cap .028 is the points setting... my feeler only goes to .024 so i was going to combine .004 and .024 to come up with .o28 but at its widest opening point i couldnt get even the .024 gauge in between so i think maybe the points being to far in could be my problem? also whats the torque setting for the flywheel nut on this old girl anyone?

 

[clearwatguy]

Re: 1972 evinrude 125 issues

Yep, you are right-the later models have a coil for each plug. Another problem with trying to diagnose from my old memory. Having the luxury of a second engine lets you change components and see the result-without having to spend any $. What a rairty in the boat business!

oh trust me being my first marine engine you have forgotten more than i will ever know! i so appreciate the help! it is nice to have swap parts for sure!

 

[emdsapmgr]

Re: 1972 evinrude 125 issues

100-105 ft lbs on the flywheel nut.

 

[clearwatguy]

Re: 1972 evinrude 125 issues **update**

Re: 1972 evinrude 125 issues **update**

just wanted to thank emdsapmgr for the help!! left for the lake Saturday got her in the water and it would barely start, got it running and went out a bit away from the launch and she quit and wouldn't start but was trying so i took the flywheel off again there on the lake and put the points back to .006 put her back together and she fired right up. now it SAYS on the motor and it says in the manual that it should be .028 but it wont run that way it just wont! i noticed while trying to adjust the carbs underway that if i put my finger over the bottom carbs starboard jet and stopped the fuel from spraying out it would pick up and run better... so i took the carbs i took off the old engine and swapped them lock stock and barrel choke solenoid fired it up and it runs much better it even planes! so thank you all and "hey riddlin boy... bring on that canoe now!!

I did the compression test again after seafoaming and when it was warm and with the throttle open and the 2 cys that were in the 120's came up to low 130's

im going to do a new post in ref to the points setting because its just blowing my mind!

 

[emdsapmgr]

Re: 1972 evinrude 125 issues

Looks like good news! If carbs sit for a long time with fuel in them, the fuel will dry up-leaving the thick gel part of the gas dired in the cab passages and jets. Carbs won't flow fuel properly that way. Likely the carbs you took off just need a good cleaning and new carb kits. It is good that the compression came up somewhat-indcates that you had some carbon around the piston rings. It should run better and you should notice easier starting and smoother idle.

 

[F_R]

Re: 1972 evinrude 125 issues

I'm glad you got it running, at least sort of running. But as for a bit of information to anybody else that may read this thread, it would be interesting to know how you set the points on a motor that doesn't have points. Oh, you mean the sensor-to-trigger wheel gap. That is supposed to be .028. It might run with a closer gap, but I'll bet your timing is off now.

OR-----did somebody put a points-type ignition system on your 125??? The points type system is supposed to be gapped at .010 for new points, .009 once they are used.

 

[clearwatguy]

Re: 1972 evinrude 125 issues

I'm glad you got it running, at least sort of running. But as for a bit of information to anybody else that may read this thread, it would be interesting to know how you set the points on a motor that doesn't have points. Oh, you mean the sensor-to-trigger wheel gap. That is supposed to be .028. It might run with a closer gap, but I'll bet your timing is off now.

OR-----did somebody put a points-type ignition system on your 125??? The points type system is supposed to be gapped at .010 for new points, .009 once they are used.

well they sure look like dual points to me they have contact points and condensors, they have arms leading from the movable contact point to a spring and a rubbing block that runs on a lobed cam on the shaft to open and close the gaps. there is nothing electronic under that cap at all no sensors no modules. under the flywheel i have a distributer cap with built in wires (they do not appear to be removable) and a stator around its outside, 3 screws come out of that and it comes off and under that is a wave washer and a rotor. under the rotor there are 2 sets of things that appear to be points with adjustable screws to open or narrow the gaps. it says on the distributer cap "set sensor gap to .028) BUT it will not run if i set the things that appear to be dual points to .028 it will NOT start. i checked them before i adjusted them to .028 and they were .006 so that is where i put them back and it runs good.

 

[F_R]

Re: 1972 evinrude 125 issues

well they sure look like dual points to me they have contact points and condensors, they have arms leading from the movable contact point to a spring and a rubbing block that runs on a lobed cam on the shaft to open and close the gaps. there is nothing electronic under that cap at all no sensors no modules. under the flywheel i have a distributer cap with built in wires (they do not appear to be removable) and a stator around its outside, 3 screws come out of that and it comes off and under that is a wave washer and a rotor. under the rotor there are 2 sets of things that appear to be points with adjustable screws to open or narrow the gaps. it says on the distributer cap "set sensor gap to .028) BUT it will not run if i set the things that appear to be dual points to .028 it will NOT start. i checked them before i adjusted them to .028 and they were .006 so that is where i put them back and it runs good.

Well ok, you have convinced me, somebody has modified that motor. That absolutely is not the way it came from the factory. In fact, the smaller motors that had points to trigger their electronic ignition didn't even have condensers, just points. Besides, the 125 didn't have a lobed cam, so you might not even have a real 125. Like I said, somebody has modified it.

Oh, and the spark plug wires can be removed--they screw into the cap. Unscrew to remove.

 

[clearwatguy]

Re: 1972 evinrude 125 issues

Well ok, you have convinced me, somebody has modified that motor. That absolutely is not the way it came from the factory. In fact, the smaller motors that had points to trigger their electronic ignition didn't even have condensers, just points. Besides, the 125 didn't have a lobed cam, so you might not even have a real 125. Like I said, somebody has modified it.

Oh, and the spark plug wires can be removed--they screw into the cap. Unscrew to remove.

ok is it possiable that maybe the motor cover is from a 125 and the actual motor is somthing smaller? its a dual carb v-4, i have interchanged the carbs, starter solonoid, choke solonoid and fuel pump from the other motor that is known to be a 125 by the data plate (the mounted motors plate is missing) is there some other way to tell? just seems like a lot of work to put lobes on a shaft that didnt have any lol

 

[F_R]

Re: 1972 evinrude 125 issues

ok is it possiable that maybe the motor cover is from a 125 and the actual motor is somthing smaller? its a dual carb v-4, i have interchanged the carbs, starter solonoid, choke solonoid and fuel pump from the other motor that is known to be a 125 by the data plate (the mounted motors plate is missing) is there some other way to tell? just seems like a lot of work to put lobes on a shaft that didnt have any lol

Very easy to swap covers. Lift one off and lift another on. Is the round core plug missing from the top of the block--the one with the model and serial numbers on it? There were so many models that look the same on the outside.

You could pull the head and measure the bores. But maybe they just swapped crankshafts and kept the 125 block. Lobed cranks were used in 85 and 100hp.....I think without looking it all up.

 

[clearwatguy]

Re: 1972 evinrude 125 issues

Very easy to swap covers. Lift one off and lift another on. Is the round core plug missing from the top of the block--the one with the model and serial numbers on it? There were so many models that look the same on the outside.

You could pull the head and measure the bores. But maybe they just swapped crankshafts and kept the 125 block. Lobed cranks were used in 85 and 100hp.....I think without looking it all up.

ill look when i get home, the data plate on the mount is missing for sure, i know the hoods remove easy but i didnt think they would be interchangable, i figured the hoods would all be different

 

[emdsapmgr]

Re: 1972 evinrude 125 issues

As F_R indicated, you should check the core plug on the top of the block for the ID of your engine. Look for a plug like this attached pic. It may be painted over, but it will contain the info on what this block is.

 

[clearwatguy]

Re: 1972 evinrude 125 issues

As F_R indicated, you should check the core plug on the top of the block for the ID of your engine. Look for a plug like this attached pic. It may be painted over, but it will contain the info on what this block is.

nope it is a 125 and so is the spare motor i checked them both i have nooooo clue lol