My 1972 40HP Evinrude won't start....UPDATE...and help needed

Huntleybill

Petty Officer 3rd Class
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Aug 11, 2011
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Model # 40202E

So far, I have performed the following steps. PLEASE add your advise on what I should do next. I am also posting this detailed update in hopes of helping someone else in the same situation.

Problem: Motor cranks but does not start. No popping, no sputtering at all.

  • Checked for spark by using a screw driver in the spark plug wire 1/4" away from head. No spark
  • Checked again with scredriver 1/8" from head. Blue spark present
  • Just for the heck of it, I switched spark plug wired. squirted gas mix directly into cyl. Got a big backfire.
  • Set spark plug wired back. Squirted mix directly into cyl.Got nothing. Cranks like crazy but does not even pop.
  • Disassembled and cleaned out carburator/reinstalled. Tried starting, no result
  • Mounted compression tester: Top Cyl. 80, Bottom Cyl 74
  • Poured teaspoon of 30W oil in each cyl. Rechecked compression: Top cyl 110, Bottom 118
  • Removed flywheel to check keyway. NOT sheared
  • Checked point gap: One was at 20K the other about 3K. Set both to 20K.

Before I put it all back together, is there ANY THING else I should do/Check?

Thank you
Bill
 

Daviet

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Re: My 1972 40HP Evinrude won't start....UPDATE...and help needed

What do the coils look like, any cracks or discoloration? Spark should jump 1/4", maybe coils are a little weak.
 

Huntleybill

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Re: My 1972 40HP Evinrude won't start....UPDATE...and help needed

What do the coils look like, any cracks or discoloration? Spark should jump 1/4", maybe coils are a little weak.

I went out and took a picture of it. The coils look new to me. I see no cracks or discoloration.

I found this white wire that comes from the coil area and just ends. I put a white paper towel behind it so you can see it better in the picture. It is melted in the middle probably from being up against something hot...or????

Is it possible that this is supposed to go somewhere and is important?????

motor.jpg
 

Daviet

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Re: My 1972 40HP Evinrude won't start....UPDATE...and help needed

I beleave white wires are associated with the starting circut, could it be going to the safty switch? Does the engine start properly?
 

Huntleybill

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Re: My 1972 40HP Evinrude won't start....UPDATE...and help needed

I beleave white wires are associated with the starting circut, could it be going to the safty switch? Does the engine start properly?

It doesn't start at all.
 

Daviet

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Re: My 1972 40HP Evinrude won't start....UPDATE...and help needed

Sorry, I meant to ask if the engine will turn over with the starter?
 

ONERCBOATER

Chief Petty Officer
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Oct 11, 2010
Messages
536
Re: My 1972 40HP Evinrude won't start....UPDATE...and help needed

umm i think he meant turn over with electric starter motor.
ok you have enough compression to run... i personally like to see 3/8" spark jump as when in compression mode much harder to spark.
lets play a bit with assumptions... you have compression, you have spark.... add air and fuel you should get bang even if not at right place. so....... take rag... soak with gas.... put over carb 1 two layers of rag thick.... try to start.... if it does start DO NOT RUN it this way... this is a check rag with gas acts as carb will start out rich and lean quickly.... if it does start that way... then you can be pretty certain that it is carb issue. alternatively you can use spray bottle and spray directly into carb(s) with 50:1 mix this will provide lube and can be used for quite a while safely. thinking this will allow you to eliminate or focus on the carb. I know you already tore it down and cleaned it up.... but.... just to make sure before you start chasing electrical stuff and going bald from pulling your hair out. it is a cheap to free check.
other things worth checking is that you have spark on all cyl. you can also manually choke it with hand... this will sometimes allow an engine with failed failing reeds to fire and run.... speaking of reads... how long since it last run it is unlikely but reeds can get stuck closed if they used a castor based oil. also... did you for sure get every last lil passage way and jet clean on the carb when you cleaned it?

Sean
 

soundchaser

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Dec 8, 2009
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176
Re: My 1972 40HP Evinrude won't start....UPDATE...and help needed

Those coils are original coils. They could be good, But I'd at least cut some spark plug wire off and shove some new wire back into those coils.
 

strtbobber

Petty Officer 1st Class
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Oct 12, 2010
Messages
212
Re: My 1972 40HP Evinrude won't start....UPDATE...and help needed

I don't really have advice, but I can tell you that on my 1977 55hp, I had no idle. I disassembled, reassembled and reinstalled the carbs. And I mean I CLEANED them. It ran NO different. I purchased 2 carb kits, rebuilt them and it idles now. So, just sayin', I'm no longer a huge believer in only cleaning carbs. My carb kits cost me $32 a piece and I think it was money well spent. I hope, in some way, this helps you a bit. Good luck!!
 

freddyray21

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2,460
Re: My 1972 40HP Evinrude won't start....UPDATE...and help needed

you can have spark that will fire a plug, but not under compression. it may be the condensers are weak. At five bucks a piece I would change them while I have the flywheel off.
 

soundchaser

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Re: My 1972 40HP Evinrude won't start....UPDATE...and help needed

take drain plug out of carb, Pump ball. See if it flows good and evenly. if not clean the carb and make sure you remove the needle valve body from the carb body and clean behind that.
 

Huntleybill

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Re: My 1972 40HP Evinrude won't start....UPDATE...and help needed

OK..another update:

Since I didn't check my computer to read the last few posts before I put the engine back together, I put it back together to try again. No luck so, I checked the plug gap ( I know..I shoulda done that a long time ago) Gap was about 18-20. I reset to 30. squirted some mix in, put the plugs back in and it fired!!!IT DID NOT START, but it popped and almost started. (was time for bed)

Today, I tried again and can get the motor to pop and fire, but not start. I have to have the choke fully on and after a few cranks, gas is pouring out the carb throat.

Doing all the cranking I drained the battery so I stopped for awhile.

Any further ideas????? YOU GUYS ROCK, I'm feeling better about this motor!

Thank you so much for your help
 

Huntleybill

Petty Officer 3rd Class
Joined
Aug 11, 2011
Messages
76
Re: My 1972 40HP Evinrude won't start....UPDATE...and help needed

take drain plug out of carb, Pump ball. See if it flows good and evenly. if not clean the carb and make sure you remove the needle valve body from the carb body and clean behind that.

Ok....I took out the drain plug. It is flowing smoothly even without touching the ball
 
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