help with johnson 70

mikelittleg

Recruit
Joined
May 21, 2004
Messages
4
1975 johnson 70 it seems to run fine in the yard with water hose on it put it in the water and it want take the gas maybe 10 mph.cleaned carbs found broke reed replaced it checked fuel filter changed fuel,pluges even sprayed fuel in cyl have good spark have good compression please help.
 

flech01

Petty Officer 2nd Class
Joined
May 25, 2004
Messages
173
Re: help with johnson 70

Its sounds like you need to check the fuel pump and check your primer bulb.
 

Walker

Captain
Joined
Jun 15, 2002
Messages
3,085
Re: help with johnson 70

Make sure the timing is advancing with the throttle.
 

flech01

Petty Officer 2nd Class
Joined
May 25, 2004
Messages
173
Re: help with johnson 70

Can you explane your problem in a little more detail. It would help alot.
 

OBJ

Supreme Mariner
Joined
Dec 27, 2002
Messages
10,161
Re: help with johnson 70

They always do that Mike....didn't ya' know that!!!??? LOL.<br /><br />When ya' cleaned the carbs, did you blow out all the passages with carb cleaner and follow up with air? Did you install new gaskets and such from a carb kit?<br /><br />We probably need to look at the easy stuff first. Check all the fuel lines inside the engine cowl and the fuel line to the engine. Is the tank venting OK? Look for fuel lines that have become stiff with age and replace. Check the primer bulb dosen't have any valves that have fallen apart.<br /><br />How's the spark. Can each spark jump a 7/16" gap with a hot white spark?<br /><br />Do a compression test on each cylinder. All may be OK but it will also give you a reference for the future.<br /><br />Did you check the sync and link? This puts the timing and throttle plate in time.<br /><br />Do you own a manual? Most important part of any job is a service manual you can go by. You can get the generics from her on iboats. OEM's can be had from a couple different places. Let us know and we can give you the links if you don't have one.<br /><br />Keep us posted....thanks.
 
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