'75 Evinrude will not accelerate

[DustinMcCormack]

I have a 1975 Evinrude 6hp that will not accelerate. I bought it the way I am explaining it. It bogs down when the rpms are barely above idle. It will always start with just 1 or 2 pulls and idle real smooth.

I have cleaned and rebuilt the carb, rebuilt the fuel pump, compression is 65psi in top cylinder and 60psi in the other(which seems borderline low), verified the the points were set correctly, it has a brand new tank and fuel lines.

The bulb is always tight and I tried spraying premix in, but it just floods and kills it. I'm at a stand still because of my lack of experience with outboards. Any help would be appreciated before I have to tear into this thing any deeper.

Also, just curious to what would happen, I disconnected the fuel line and put it at WOT and right before it ran out of fuel it went to WOT.

 

[racerone]

Re: '75 Evinrude will not accelerate

That sure sounds like blockage in the carburetor,-------Did you remove the high speed jet / orifice that is screwed into the carburetor bowl.----It screws in behind the drain plug and should be removed for cleaning.---------Does spark jump a gap of 1/4" or more on both cylinders.----Only spark that can jump that gap with a snap you can hear is considered " good spark "

 

[boobie]

Re: '75 Evinrude will not accelerate

Is the high speed jet even in the carb bowl ??

 

[DustinMcCormack]

Re: '75 Evinrude will not accelerate

The high speed nozzle and orifice are both in the carb and I cleaned the carb really well when I rebuilt it.

I checked the spark and they both spark but only one of them will jump about a 1/4in. I pulled the coils and tested them. Coil 1 has 6500 ohms and coil 2 only has 3900 ohms. I read somewhere that its supposed to be between 6000-9000 between the ground and the tack where the plug wire attaches. It seems like coil 2 may need replaced.

Does it seem like I'm headed in the right direction?

 

[Bosunsmate]

Re: '75 Evinrude will not accelerate

Pulling the plug makes it run lean just before it cuts, running lean increases power but also the heat so will kill a motor quickly if its run lean often.
Swap your coils over and see if that makes any difference in the spark.
Try a drop test to check the motor is running on both cylinders

 

[DustinMcCormack]

Re: '75 Evinrude will not accelerate

Both cyclinders are definitely firing. Not sure how I missed this, but the coil that is also out of parameters on the resistance is also cracked. Im gonna pick up a new coil tomorrow and install it and then I'll let yall know what happens.

 

[DustinMcCormack]

Re: '75 Evinrude will not accelerate

I replaced the bad coil and now I have good spark. It is still running like crap. Runs good up until I get over about a 1/4 throttle and then bogs down. Im at a complete loss. I have no clue whats wrong. I'm still to cheap to pay $90/hr labor.

 

[racerone]

Re: '75 Evinrude will not accelerate

Checked reed valves?-----Checked / removed high speed jet found in the carburetor bowl for cleaning ?-------The high speed jet is about 5/8" long and screw into the bottom of the bowl.

 

[kbait]

Re: '75 Evinrude will not accelerate

Did you forget to replace the cam follower/linkage? That's the apparatus that rides on the armature plate cam.. Cam pushes follower, follower pivots and pushes the linkage arm that's connected to carb throttle butterfly - opening it as you increase throttle setting. If you forgot to re-install, it will just bog at anything over idle setting as the throttle butterfly will stay closed..

Good luck!

 

[DustinMcCormack]

Re: '75 Evinrude will not accelerate

The cam follower linkage is all hooked up and operating properly.

I did clean the high speed nozzle and the orifice. The carburetor is clean. You said to check the reed valves. Are those the little flaps that are in the intake? They kind of look like a "U" or a "V". I have not checked those. What exactly do those do? I dont remember seeing anything like that last time I had the carb off.

 

[boobie]

Re: '75 Evinrude will not accelerate

Did you hit the choke when this happens ??

 

[DustinMcCormack]

Re: '75 Evinrude will not accelerate

It starts well without the choke. If I hit the choke it will just kill it.

 

[Daviet]

Re: '75 Evinrude will not accelerate

Did you try spraying the fuel mixture into the carb when it was wide open?

 

[DustinMcCormack]

Re: '75 Evinrude will not accelerate

Did you try spraying the fuel mixture into the carb when it was wide open?

I did and it kills it

 

[DustinMcCormack]

Re: '75 Evinrude will not accelerate

Checked reed valves?-----Checked / removed high speed jet found in the carburetor bowl for cleaning ?-------The high speed jet is about 5/8" long and screw into the bottom of the bowl.

Reed valves are there and appear to be closed. They easily opened when I pushed them with a screw driver.

 

[Daviet]

Re: '75 Evinrude will not accelerate

Did you check the float setting, is it level with the carb body?

 

[DustinMcCormack]

Re: '75 Evinrude will not accelerate

Did you check the float setting, is it level with the carb body?

I set the float. It is level with the body and the drop is between 1" and 1 3/8"

I have not replaced the condensers. If I have a bad condenser or ones that are going bad, would they cause intermittent or misses at increased RPMs?

 

[DustinMcCormack]

Re: '75 Evinrude will not accelerate

Okay, so after doing a complete tune up I have found something out. The engine will start and idle just fine but under normal conditions it will not rev up to WOT.

When I start it, it will idle just fine. When I rev it up it will bog down. When I rev it up just a little bit, I put my finger over the hole that is pointed out it the picture and it will allow me to go WOT but if I keep my finger over the hole and go back to idle it will die. That hole is confusing me.

 

[ultra353]

Re: '75 Evinrude will not accelerate

Did u make sure the bowl to nozzle gasket is there ?

 

[DustinMcCormack]

Re: '75 Evinrude will not accelerate

Yes it's there