1972 Evinrude 25hp Fuel Leak

[cpr12284]

I have a strange leak on my 1972 Evinrude 25 (model 25252R). I have replaced the crankshaft seal, replaced all the fuel hoses, and sealed up the bypass cover gaskets. Fuel seems to be finding its way all over the motor, but a major concentration near the carbuerator. I have made sure the float is adjusted properly and the needle valve is in fact shutting off the fuel supply when the float is closed. The only thing I can think of is fuel is coming back out through the carb. Anyone have any ideas what I can do to remedy this? The motor is quite young, when I acquired it, it had less than 25 hours on it and looks like new. This is the 2nd carb i've had on the motor, too.

 

[fireman57]

Re: 1972 Evinrude 25hp Fuel Leak

Pull your carb and get a flashlight and shine it back in the reed valves and see if there is a bolt or something lying in there. It wil be easily seen.

 

[cpr12284]

Re: 1972 Evinrude 25hp Fuel Leak

A bolt, you mean just lying around in the bottom of the plate that covers the reeds? Or an actual bolt in the reed plates, or one that should be in the reed plates that isn't?

 

[cpr12284]

Re: 1972 Evinrude 25hp Fuel Leak

No bolts laying around. Replaced both gaskets, and checked the reeds. Local outboard mechanic said they were in A1 condition. So I reassmebled. Don't think its leaking fuel any more out the carbuerator. But at midrange, around half throttle, it has a skip in it. If you let it be for a few seconds it works itself out of it.

I wonder if I shold be using 89 or 91 octane fuel instead of 87? Does the kind of oil used make a difference? Should I use Johnson/Evinrude TCW3 oil or is the Havoline oil fine?

 

[Paul Moir]

Re: 1972 Evinrude 25hp Fuel Leak

Nah, none of that will make a difference. Have you done a link & sync?

Midrange also suggests weak ignition perhaps.

 

[cpr12284]

Re: 1972 Evinrude 25hp Fuel Leak

Got a link to the link n' sync page that describes how to do it? Can't be ignition, all components are BRAND NEW and adjusted properly

 

[Paul Moir]

Re: 1972 Evinrude 25hp Fuel Leak

Set throttle to idle (engine off & in gear). Exaggerate the motion of the throttle butterfly shaft on the carburetor by attaching a piece of stiff wire. Open the throttle slowly until the wire *just* begins to move. At that point, the roller that follows the cam on the armature plate (the part the coils mount to) should be right between the two marks on it. If it is not midway between the two marks, loosen the linkage clamp on the throttle butterfly shaft and adjust it slightly.

If that's not it, then has the carburetor been rebuilt? How do the spark plugs look? (black/oily/tan/white?)

 

[cpr12284]

Re: 1972 Evinrude 25hp Fuel Leak

I dont see any linkage clamp on the throttle butterfly. Just an arm with a neoprene bushing that rubs against the coil plate. Any other ideas? Or is there an adjustment and I just can't see it.

 

[Paul Moir]

Re: 1972 Evinrude 25hp Fuel Leak

Clamp is part 53. Butterfly shaft is #12:

Follower is #17. Link 19 ties the clamp to the follower.

This is the sort of thing a manual is helpful for.

 

[cpr12284]

Re: 1972 Evinrude 25hp Fuel Leak

Here are some pictures to clarify. Maybe you can point me in the right direction when you see what I'm working with.

 

[Paul Moir]

Re: 1972 Evinrude 25hp Fuel Leak

Thanks, sounds like we're on different pages here. Try tinypic.com

 

[cpr12284]

Re: 1972 Evinrude 25hp Fuel Leak

Here. GO to www.winds.org/~coke/pics/outboard1.jpg and www.winds.org/~coke/pics/outboard2.jpg. Thats what I tried to show you in the previous post.

 

[Paul Moir]

Re: 1972 Evinrude 25hp Fuel Leak

OK, now we're getting somewhere. This must be your 2nd carb right?

That's not a '72 25hp carb you've got there. More like around '75. The '75 was adjusted not by loosening the clamp, but that brass link rod you see was in two parts with a clamp holding the two parts together.

So you've got no adjustment there at all. You'll have to figure out how to get some in order to do the link & sync. I'll bet it's way off though.

Also, there's supposed to be a link running between the choke butterfly arm and the throttle butterfly arm. This opens the throttle a little when the choke is applied. You probably are getting a little hard-starting from that being missing.

 

[cpr12284]

Re: 1972 Evinrude 25hp Fuel Leak

This is the 2nd carb. I still have the first one though, and it does have the adjustable link. It will be going back on tomorrow, as there was nothign wrong with it in the first place. I never had an adjustable arm that applied fuel while it was choked. I had an electric choke solenoid which I just took off because I didn't have it hooked up and wasn't using it.

So let me get this straight - If I put the other carb back on tomorrow, the carb should just start opening between the two lines on coil plate assembly, correct? And I can adjust this by the adjustable arm on the butterfly plate arm, as shown in the diagram you posted, correct?

 

[Paul Moir]

Re: 1972 Evinrude 25hp Fuel Leak

Correct. You want to set so it happens when it precisely mid-way between the two marks. This is a critical adjustment for good running at part throttle and is very important for fuel economy.

The link between the choke & throttle plate was only on the later carbs, not the '72. That's not the first one I've seen missing though - I think they fell off rather easily.

 

[cpr12284]

Re: 1972 Evinrude 25hp Fuel Leak

Okay, thanks very much for your help. I will tackle this tomorrow and report my findings.

 

[fireman57]

Re: 1972 Evinrude 25hp Fuel Leak

Sorry, I've been gone. Seems like the experts have you going in the right direction. The reason I mentioned the reed valves is because you said that fuel was being pushed back out of the carb. A flashlight in behind the carb will show anything that is sitting in there. Could be junk from your insulation or anything else. Glad there wan't anything there. You said it is not leaking anymore so I guess you had a bad gasket. Stay with 87 octane anything else is a waste of money. If you go to a higher octane rating you run the risk of predetonation.

 

[cpr12284]

Re: 1972 Evinrude 25hp Fuel Leak

Update: Seems to be fixed. Thanks for all who replied and pointed me in the right directions. I actually had to swap the butterfly and throttle arm out of my old carb into the new one. What a pain that was. But, I think I got it where it needs to be. I didn't notice any skipping or loading up. Of course, I took a screwdriver to the lake with me in case I had to adjust the arm again, which I did, but all is well. Thanks!

 

[fireman57]

Re: 1972 Evinrude 25hp Fuel Leak

Glad to hear it and thanks for posting the solution. Paul Moir might not be the best but he is in the top two!