Don't know were to start

sgt stump

Recruit
Joined
Apr 25, 2007
Messages
4
I have a 1978 115 Evenrude it cranks good and will riv up with the cranking lever pulled up and it will idel. But when I put it in gear to go forword it won't go but about 8mph. The man that gave it to me said that it did same thing on him also. He said it takes 5 min. to and hour then the egine will make a sound and the motor will take off and run well the rest of the day. I've heard to check the power head the distrbiture the spark plugs and coils. But I don't know were to start
 

jtexas

Fleet Admiral
Joined
Oct 13, 2003
Messages
8,646
Re: Don't know were to start

welcome to iboats!

When was the last time the motor was used, before you acquired it?

There's a lot of difference between 5 minutes and an hour - did the motor "take off and run well" for you like he said it would?

Your motor has a "capacitor discharge magneto" ignition - instead of distributor and points you have two "powerpacks", one for the starboard side & one for port.

Step 1: get over to kencook.com or marineengine.com and order yourself an original factory shop manual - it will pay for itself many times over.

Step 2: pull and inspect the spark plugs; they should be champion QL77JC4 gapped at .030 - note the appearance (color of the insulator, carbon deposits, rust, etc.)

Step 3: get yourself a compression gauge (around $20??) and check the compression on all 4 cylinders; write down the numbers & post 'em here.

Step 4: spark tester (couple bucks at auto parts store), set the gap at 1/2", look for a strong blue spark.

report your results.
 

tashasdaddy

Honorary Moderator Emeritus
Joined
Nov 11, 2005
Messages
51,019
Re: Don't know were to start

agree do 2, 3 and 4 before ordering the manual, may not be worth the cost of the manual.
 
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