rmelanimek
24.05.2021 2:16:57
My mechanic says they could trouble shoot it fairly easily if they could just get it to fail in the tank. Frustrating that it runs fine in the tank, but awful when out on the water. here
See full version: Evinrude power loss troubleshooting
My mechanic says they could trouble shoot it fairly easily if they could just get it to fail in the tank. Frustrating that it runs fine in the tank, but awful when out on the water. here
So after checking the gas I took it to my mechanic who suggested an ignition problem. First they checked compression which was on the money between all 3 cylinders. and had good spark on all 3 cylinders. They put it in the test tank and couldn't get it to fail. Being an intermittant problem my mechanic suggested that it could be the power pack. I agreed and got it replaced. They tested it again after replacing the pak - all looked good. I took the motor out. same problem reared it's ugly head. Took it back, ran it in the test tank and I was there. It ran like a scolded dog for 20 minutes - no problem. Well, he said he would still dig deeper. took the flywheel off and the stator showed signs of melting. Went ahead and replaced that. while he was in he also replaced the recitifier. Felt certain this had to be the problem and that the motor was failing after heating up. Tested the boat in the tank after replacing the stator and all was good. I get the boat and take it out. same old problem. At first it seemed like it might do OK. ran OK at idle speed and too off like a shot from a gun when putting up on plane - for a second I thought all was good. then it bogged down again. AHHHH. [links]
Going back to the basics I got a spare gas tank that my buddy had been running on his Evinrude all week and tried that just to rule out gas again. Same old problem. sounds like it's running on 2 cylinders or not getting gas. No problem starting and it normally runs at idle speed well and just gets worse when runnning it hard.
I'm having a problem with my 1990 Evinrude 70hp losing power while on plane. The problem has been intermittant and it doesn't show the same exact symptoms every time out. I have a really good mechanic who does my work for me, but when the problem first surfaced I immediately checked all the obvious stuff related to gas. New, gas, new tank, new hoses, etc. Same problem, runs good at idle AT FIRST then put it up on plane, run for a bit then it looses power and sometimes cuts off, but most of the time just bogs down until I am at 3/4 throttle and barely making way. [links]
Hopefully he ran it in the tank again this evening and got it to fail. If not I suggested going ahead and replacing the 3 coils. He also said he was going to pull the carbs and take a look for any varnish, etc.
For more information on lift pumps, FSM’s, or VST’s and this issue. Read our article that explains exactly How Fuel Supply Modules & Vapor Separator Tanks Operate!
Fortunately, the other style of pumps are mechanical fuel pumps. And they are a little easier to work with.
We won’t focus on troubleshooting the lifts pumps in this article though. Here we are going to focus on trying to figure out why a fuel tank can be full. Have a properly operating lift pump. And still, experience an engine running out of fuel.
Then a while later ran it flat out and it went good again, then when i slowed down i knew it didnt sound right and would only go slow .
limped back to the dock and switched it off,let it cool down even though the head felt stone cold.
20 minutes later it started up straight away but sounded like it was missing real bad.
It wouldnt rev and realy sounded rough.
fuel primer still nice and firm, but engine a bit smokey,would not even rev up much on the warm up lever.
the engine just wouldnt respond to throttle and coughed a couple of times as well.
"Slow Mode' is an overheat issue or at least the "temp sensor" thinks there's one. It would make sense in that it "corrected itself" which could be the sensor going bad or even a bad wiring connection. I wouldn't imagine it to be fuel related, or again, wouldn't correct on it's own. Out of curiousity, what type fuel tank do you use? here
the fuel tank is also a brand new hulk 30 litre plastic tank.
fuel fittings are all good,no air leaks etc,tank vent open,no kinks in fuel pipe (also new). [links]
Adjusting the idle on an Evinrude outboard motor helps to increase the motor's efficiency. This is particularly important if you use your motor as a trolling motor in addition to a main source of propulsion. Just like any of the other small maintenance chores, you can adjust the idle yourself with a minimum of fuss and tools.
Turn the idle speed screw with a standard slotted screwdriver until the tachometer indicates the idle speed is between 800 and 900 RPM. here
Tighten the idle speed screw lock nut. [links]
That's of course down to fuel starvation - if you suspect that the fuel tank cap is at fault slightly unscrew it to allow air to come through so it's doing the job of the actual valve itself. Run the machine again and if it runs correctly it's just a case then of replacing your cap and all should be okay. more
Another common cause of bogging down can be the fuel tank cap. There is usually a special one-way valve in the fuel tank cap that allows the air to come in to the top of the fuel. When these valves fail to work the fuel can't leave the fuel tank, because it creates a vacuum lock as there's no air coming in to replace the lost fuel.
The barrel gasket, also known as the pop gasket, sits at the split junction between the barrel and the crank case beneath it. The gasket allows you to separate the barrel and the crank case for any repair works. They are made from a range of materials from paper/cardboard to metals and their job is to keep the seal between the barrel and the crank case. It's vital that the gaskets are in good working order, because if they're not each time the piston goes up to draw an air fuel mixture it can also draw in air if there's any damage around the gasket. By this point the air fuel mixture would be correct, so any extra air coming in will cause the engine to cease working, particularly at high revs.
The first thing to check before anything else is the mixture screws. The fuel air mixture screws on the side of the carburettor are marked H for High for the engines high speed adjustments and the L means Low for the engines low speed adjustments.
Starting with the H screw, the screw itself goes into the carburettor and protrudes into the high jet where the fuel comes from above. Because of the screws restriction there's less fuel below the screw than there is above it. So if we turn this screw in even more it will restrict the fuel even more, and if we turn the screw out it will let more fuel through.