1988 Evinrude 60HP stumbles

[retiredfornow]

E60TLCCR, new power pack, new fuel pump, new carb kits, new hose and bulb, 120, 110, 120 compression, new plugs. Starts right up, in gear at a fast idle runs fine, then when I give it more throttle, it stumbles and dies. Run it in fast idle, give it more throttle and quickly twist the manual choke and it'll clean out and take off.
So it appears that the quick shot of fuel gets it off the stumbling block. Would the problem be in the choke? I had 2 other mechanics go thru the carbs and they couldn't find anything wrong there. It has a 13x17 prop, is that too steep? The only thing I haven't changed yet is the small fuel lines at the carbs from where the fuel pump hooks into the fitting.
In neutral, it screams like a banshee when you manually flip the throttle linkage. Anyone have any ideas????

 

[retiredfornow]

Re: 1988 Evinrude 60HP stumbles

Found a crack in one of the lines from the fuel solenoid to the middle carb. Replaced with all new hoses. Got my service manual in the mail Saturday and I had the carb linkage off a little bit from the cam mark. Will try it out in the morning.
Question: Will a cracked "choke" line be causing this problem? Kind of like a vacuum leak?

 

[Sixmark]

Re: 1988 Evinrude 60HP stumbles

I really hope you are not revving the **** out of it on the water muffs, it's one thing to do it on muffs versus in the lake.

You seem to have listed multiple problems as you said you saw the linkage was off and that you had cracked fuel lines, fix the obvious problems and then test it again and see where you are at then. You may have to start from square one and test all over again, the reason being that these other repairs you are making can affect the baseline performance that you are supposed to be using to make changes from.

 

[retiredfornow]

Re: 1988 Evinrude 60HP stumbles

Thanks, Six. I believe I have all the obvious problems corrected now. This is the 5th week of me ever seeing a boat motor with the cover off, but I'm learning. I put the boat in the water whenever I'm testing something. I'll see how it does in the morning.

 

[retiredfornow]

Re: 1988 Evinrude 60HP stumbles

Decided to check the timing, even tho the other 2 mechanics said it was good. Since my old timing light walked off somewhere, bought one at Autozone, along with a spark tester ($6.99).
I used the timing procedure in the Top Secret file, and adjusted the timing via the timing adjustment screw under the flywheel. Checked the TDC pointer, it was OK. Timing on this motor is 19 BTDC, so I was looking for 15 degrees (19 minus 4 per Top Secret file). Wired the timing advance against the stop screw and lo and behold, she showed 6 BTC. Adjusted it to 15, rechecked the link and sync and took it out for a run. Ran like a champ!!!! Even sounds different! It did load up when I shut it down to neutral from full plane, so I'm learning. Now it will push itself back on the trailer now!
One question-where should the cavitation plate be in relationship with the water line while sitting still? Thought I read somewhere that it should be at the water line, this one is about 3" below water line. I have adjustment to bolt it higher on the boat if need be. Thanks.

 

[DJ]

Re: 1988 Evinrude 60HP stumbles

1. Your cav. plate should be even with the boat keel, or slightly above.

2. The "sync./link" is paramount on those three cyl. "loopers". Make sure it's right.

3. Also, if the idle mixture is too lean, it will stumble on accel.

 

[retiredfornow]

Re: 1988 Evinrude 60HP stumbles

Thanks DJ, I'm going to double check everything. I went out and looked, and the cav. plate looks pretty darn even with the keel.
I'm going to run a couple tanks of gas thru it (I hope) and see how it's doing. It has, by guess, a 19 pitch prop on it. No marks on it anywhere. May go down to a 15? pitch to get it up quicker. Pretty shallow here on the flats, not much running room.
Oh, I think the only way to adjust the idle mixture is change the jets. I pulled the plugs and it looks OK, but that was after idling and loading the boat on the trailer, not a good way to read plugs. Thanks again.