took hour to start boat and had many problems and would like some help.. thanks?

Question

First ill start off that i have a 1974 evinrude 115 hp motor. 4 cylinder. motor sat for 3 years. i have changed the fluids and also changed the impeller. cleaned out the carbs and the fuel lines going to the carbs but not the line from tank to filter.
got to the boat ramp and i started in garage several times with no problem and then once i got to the boat ramp it did not want to start.. ran the battery down and hand to us jumper cables to recharge the battery from my truck. when we tried to start it i don't know how but the butterfly on the lower carb was a little open and i screwed around changing things up and once i got it closed it would flood it self. we would open the carb and fuel would flow out. i thought maybe the fuel lines were clogged but we got it started after an hour and once on the water i would have it opened up good then it would slow down and then hammer back into again by it self. i want to take my girlfriend out in it for her birthday in a few weeks and i dont want to have to paddle back to ramp.. when i tuned the carbs i did not find an adjustment screw so i adjusted them with the linkage on the side that opened and closed the butterflies. thanks for any help to come.

Answer 1

The reason you couldn't find an adjustment screw on the carbs is because they have fixed jets -- no adjustment necessary.



erratic throttle response could be due to out of sync throttle valves, bad fuel quality, or intermittent ignition fault.



get some fresh gas in there (87 octane) mixed 50:1 with TCW3 certified oil. I'd just go ahead & replace the fuel line and primer bulb, just on general principle.



Do yourself a favor and use the champion spark plugs, surface gap UL77V.



Spark should jump a 7/16" gap on an inline tester clipped to the engine block. That'll indicate strong enough ignition to consistently produce a spark under heat & compression in the combustion chamber.



Compression should be upwards of 90 on that motor, and the lowest should be within 5 or 7% of the highest.



fuel flowing out the front of the carb means that your float valves are shot and need replacing.



order a couple carb kits from iboats.com and do the carbs right -- soak the metal parts overnight in carb cleaner, blow through all the passages with compressed air (or aerosol carb cleaner).



You probably know this already -- if you're talkin bout the butterflies at the front of the carb throats, those are choke valves -- the throttles are at the back (two per carb). Adjust the roll pin clip screws to where the throttles are closed at idle (idle speed setting is done entirely with spark advance).



Here's the basics of link & sync from memory -- you'd need a manual for the step-by-step but this should get ya close. Must be done in order:

Note: if you adjusted the length of the throttle lever linkage (attached to throttle cam yoke), you're screwed -- it has to be a precise length and you'll need the service manual for your specific engine for that measurement.

1. Find the idle set screw (starboard side of the powerhead in a spring-loaded nut -- the throttle lever rests against it at idle) -- idle speed should be about 650-700 in gear in the water, so set it to about 950 in neutral on the muffs then fine tune after launching. The idle set screw shouldn't be fully in or fully out -- if it is, use the thottle cable trunion nut (black thumb-wheel-looking thing) to adjust the cable length.

2. Set the roller on the upper carb to where the throttle cam makes contact with it right at the mark embossed on the cam.

3 Find the WOT stop screw in a spring-loaded nut on the starboard side; set it to stop the throttle lever when the throttle butterflies are horizontal.



Highly recommend you get yourself a manual so you can do a proper link & sync. try iboats.com or marineengine.com

Answer 2

First and cheapest investment will be in a quality workshop manual. This will explain the exact set up for the carbies and how to correctly tune it. There are traps for the unwary when tuning the ignition systems on some of these older engines - testing in the wrong way may actually do more harm than good.



Those engines were pretty good for the time and have a good reputation in general - but even though the engine is 35 years old now your main problem will be the length of time it has sat. No two stroke will be happy with that - and at the very least you may have to rebuild the carbies, check all the fuel tubing for splits or pin-holes and make sure the ignition system is firing strongly.



Water pump impeller will possibly be getting pretty sad now too. If you have started it without any water to the leg it will be stuffed for sure.

Answer 3

Hi,

Sounds like a carb float/needle valve sticking through lack of use.