Vasiliev
08.06.2021 13:10:15
If you notice an excessive amount of wet and black carbon on your plugs, you may have a bad fuel-water mix. There also could be a leaky head gasket. See a technician. [links]
See full version: Why Does My Outboard Sputter at Full Throttle
If you notice an excessive amount of wet and black carbon on your plugs, you may have a bad fuel-water mix. There also could be a leaky head gasket. See a technician. [links]
Remove your boat from the water and place it on a trailer. Remove all your spark plugs with a ratchet and appropriately sized socket. Clean any residue from each plug contact and plug port. If you notice any erosion, replace the plug. Use a plug gap tool to set the correct measurement on your plug gaps, according to your manufacturer. Test out your boat's operation at full throttle again.
If your marine engine is sputtering, use a timing light to check each spark plug wire individually, while the engine is operating, for the proper voltage output and ignition spark (your individual model's manual will have these readings). This could indicate which plugs and corresponding fuel cylinders are giving you problems. Remember which plugs are giving you the worst voltage readings. [links]
If your outboard engine is sputtering at any speed, idle or full throttle, it could be the result of several common malfunctions. You may need to make a few timing adjustments or replace a spark plug, or you may need serious mechanical inquiry. more
Dan Harkins has been a full-time journalist since 1997. Prior to working in the alternative press, he served as a staff writer and editor for daily publications such as the "St. Petersburg Times" and "Elyria Chronicle-Telegram." Harkins holds a Bachelor of Arts in journalism from the University of South Florida.
1. It reves really high then back down then dies (when cold).
2. Does not idle in gear at slow speed.
3. Has a little trouble to stay running when cold.
I just purchased a 1986 40 HP Evinrude and got it out on the lake my self for the 1st time.
Both require complete carb disassembly and cleaning and reassembled with NEW kits. As a starting point. more
1. I opened it up to full throttle and The boat speed would only reach 105. MPH. I let it run for about 200 feet this way and it never picked up.
2. Does not idle in gear at slow speed.
3. Has a little troble to stay running when cold.
55 MPH? I also want that 8.
Re: Slow Speed at Full Throttle
Check the spark plug for damage. A functioning spark plug should be dry and grey, if it is black the engine has too much oil whereas a white color indicates it is getting too hot. If it’s not dry, this could point to water in the fuel. I’d recommend getting yourself a spark plug tester.
The general steps for cleaning a carburetor include removing the plastic air intake, fuel line, and throttle linkage. Cap the fuel line somehow, and then drain the float bowl at the bottom of the carb. The carburetor is held on by a few long bolts that are easy to remove, so the entire assembly should come off. Take care not to damage the gasket between the carb and the manifold, especially if you don’t have a spare one handy. [links]
At this point, it’s time to start double and triple-checking the fuel lines, primer bulb, and filters. Hopefully, you have spare fuel filters onboard, so changing them shouldn’t be a big deal. See if you notice any contamination or water in the fuel when you drain them, as that might be an important clue. If you have a separate portable fuel tank, try connecting that and see if the motor will run. Use fresh gasoline if you can. here
If the motor has been slow to start lately, or it turns over slower than it used to, this might also point to a dying or dead battery. Try using your other battery to start it, or get a jump from another vessel. If onshore, plug in your battery charger and give it a try. more
Idled fine prior and continued to idle fine, wouldn't die at idle RPM's. Approximately half throttle, it bogs a bit and seems to not be getting full power. Boat/motor doesn't want to "pop" on the hole shot and plan out like usual. Seems to be starving for fuel as if the primer ball isn't firm, but the ball is firm.
Fresh gas, had approximately a gallon left from last year, but topped off with 9 gallons of fresh fuel this year. Ran seafoam through the motor last year, only put 2 tanks of gas through it last year. [links]
Good water pressure, no over heat alarm. I was having issues with low pressure and over heating two years ago and replaced the impeller at the start of last year which resolved the issue. here
Day two this weekend, idled around fine in the morning. When I was done fishing, I did the test run back to the launch. Same thing, motor died at WOT after approximately a minute. more