1995 johnson 70 hp....help with fuel

[wisemack34]

ran it today run great,,,till i stopped for about 2.5 hours...then 3400 rpm is it.... it's like it's not getting fuel right...
1. does the motor use a fuel punp?
2. i un-hooked oiler a few weeks ago is it tied in to the pump...
im so lost...i put new coil packs...didn't help.
if i let it set over 4 hours it runs great......it ran out to day and died then picked back up...........

 

[OBJ]

Re: 1995 johnson 70 hp....help with fuel

What you may be looking at is some crude floating round in one of the float bowls and clogging up the high speed jet. Don't take much.

What you can do to find out is take some premix in a spray bottle with you and when the rpms drop, give each carb a shot of premix and see if the rpms pick back up. Look for the one that makes the rpms pick back up.

Or, the power pack may be failing to one of the cylinders. A timing light can help find this out. When the condition occurs, connect the timing lite to each spark plug wire and see if any have lost spark.

 

[ezeke]

Re: 1995 johnson 70 hp....help with fuel

Are you mixing fresh 87 octane gas with TCW-3 oil at a 50:1 ratio? Is the tank new?

 

[wisemack34]

Re: 1995 johnson 70 hp....help with fuel

Ok..u guys are great help..let me tell you what the boat is doing in details...and what i have do up to this point..
I can take the boat out in the morning and it runs great..stop turn the 70hp motor off and troll with the trolling motor for about 2.5 hours or less and start the 70 hp up and 3400 rpm's is it....but i can troll for about 5 hours and start the 70 hp up and it runs good....this weekend troll 2 hours stated the motor up and 3400 rpm's...i tiped the flows and played around and it started running right...for about 200 yards and died down to 3400rpms...so i left it wide open and it picked up again done it twice..it acts like it loading up with gas to much..what may cause it to load it..
1. i have unhooked the oiler.
2. i have put new plugs & wires.
3. i have put all new coil packs.
4. im thinking it's in the fuel somewhere
5. does a 95 johnson 70 hp have a fuel pump.
6. i have put both new fuel filters on it.
7. i unhooked the oiler is they right and wrong way to unhook it.....
8. after oiler unhooked does it run str8 from the hand pump?
9. i have test the psi on all three they are 120 to 119 psi.
Guy i hope this helps yawl on what i have done so far

 

[rickdb1boat]

Re: 1995 johnson 70 hp....help with fuel

The oiler is a combination oil pump/fuel pump. In detail, what and how did you unhook it? Did it run good before that? The "Hand Pump" (Primer bulb) is there for initial start-up only. You must have a fuel pump in order for the engine to run...