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1976 70 HP Hard start, shuts down when you put in gear...

jvmvjv2

New member
Hello everyone. I have a couple of questions that hopefully someone might be able to guide me. I purchased this motor and I found out from the owner that it was in storage for about 7 years. (First thing I did was buy the repair manual for it) I mounted it on a 1966 Winner 16ft fiberglass boat and I'm going to use it for fishing. Basically its my first boat. This is what I have done to it so far: Before all of this, I verified the motor started.
1. Replace water impeller
2. Replace fuel pump
3. Replace thermostat
4. Replace spark plugs and gapped at .030
5. Check cylinder compression #1-135psi #2-134psi #3-138psi
6. Replace propellar shaft seals (because it started leaking after initial start)
7. Replace lower unit gear oil
8. Replace all fuel hoses at motor including fuel hose and bulb from gas tank to motor.
9. Water intake screen
10. Check spark on all 3 coils and they all fired at a 7/16 gap no problem
Well thats pretty much what I've done. Now I took it out on the Hudson River in NJ. At first it ran great. I had good pick up and the power was there. Like I said before I'm a first time boat owner so ofcourse I messed up and ran out of gas, but I had a second 6 gallon tank just incase that happened. Here is where the problem started. I switched tanks and primed the buld untill it was rock hard. I tried starting the motor but It took a while for it to start I would say about a good 10 minutes of cranking allowing the starter to rest. After I got it started it just wasn't running right. It would sputter while in neutral and when I would shift into drive it would shut off. This went on for about half hour. Finally it would stay running while in drive but had very little power. I had it open all full thottle and it barely moved. While driving back to the launching ramp it would occasionly, out of no where, while at full throttle just accelerate and work great then it would just bogg down again. After I got home I double checked all my work and it all seemed fine. I though their might of been a problem with the spare gas tank I had so I refilled the first gas tank and took it out again, but it was doing the same thing. At this point I have all 3 carbs apart and see nothing out of the ordinary no varnish, no dirt and finally needles and seats dont look worn. When I removed the carb cover I did noticed a small puddle of fuel and oil on the bottom of the cover and when I removed the plugs they seemd to have a trace of water, not a lot but just enough to notice it. So my question is why did it take so long to start and stay running after I ran out of fuel? Why does the motor running great one moment the it runs horrible the next and it goes back to great again? And finally is it normal to find fine drops of water on the spark plugs? Any input would be appriciated. :confused:
 
My suggestion is to clean the carburetors.There is really no money involved in doing that.-----------------Check the fuel in the second tank for water too.
 
I ordered and recieved the rebuilt kits for the carbs (just to be on the safe side). I got them apart already so the hard part is done. Just waiting untill the weekend when I'm off to put them back together. I purchased a new back up tank. As far as the second tank goes I cleaned it out added fresh gas and oil to it and that will be a back up to the back up. Thanks for your suggestion racerone.
 
Hi racerone. I rebuilt the 3 carbs and today was the first nice day to take it out. So.... I took it out and it ran great on the way out. I ran it for about 30 minutes then I shut it down and did a little fishing. After about 20 minutes I decided to start it and move to another location and hear we go again... It started doing it again. It would crank and start but it would run rough. I would allow it to clear then shift it into drive and it would shut down. That went on for about an hour. Then finally it stayed on and it ran like a champ again. So once again I shut it down to do some fishing and when I tried to turn it on again it did it again. Im at my wits end. I dont know what else to look at. Any help would be greatly appriciated.
 
Hey there, I saw your forum and was wondering if you ever fixed the problem and what it was. I have an Evinrude 70hp and am having the same problem. Runs great on the trailer and at idle but when you shift it into gear it dies out. Seems like its a gas problem but can't figure it out. Please email me back [email protected]

Thanks so much;)
 
My suggestion is to clean the carburetors.There is really no money involved in doing that.-----------------Check the fuel in the second tank for water too.
I pulled my center carb off to check it out and clean .I removed to bowl off and found the low speed jet had broke off almost to the top of the throut of the carb. went to ACE got a piece of 1/16 tygon fuel line splice the brass tub back together engine runs great now .
 
In your first posting you mention water on the spark plugs.... This is very significant with the symptoms described. I have had this exact problem with the very same make/model/year.

Verify that the plugs are getting wet by retesting, ensure that fuel is clean.

If plugs are wet, then you have a water leak into combustion chamber. Prime suspects are head gasket, exhaust cover gaskets or base gasket.

Also check for water staining/dripping at the exhaust cover bolt heads.
 
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