A 90 hp on a 20 foot pontoon is going to be slow, they are heavy and not aerodynamic in the water. They are built as a stable platform generally for old folks or families. Put a 150 on it if you want speed. Also check the pontoons don't have water in them adding to the weight.
Check prop--pontoons for debris --weight distribution --trim --tune up
Sounds pretty normal. If it's loaded down, displacement hull physics come into play.
SOURCE: 40hp 1987 yamaha outboard motor will run for 30-60
Sound like the fuel pump is not keeping up with the engine's demand. Check it out. Good luck. Hope this helps.
SOURCE: 2003 115 mercury efi losing power
I am a Mercury certified technician. What you need to do is take it to a Mercury dealer and have them hook it up to the computer. It sounds like the engine could be in Guardian mode or possibly a high RPM misfire. It is not something that is common and the computer program that Mercury has for those is able to test misfires and all sorts of cool stuff. It can also tell you if the engine was broke in properly, how many actual running hours are on it and even at what RPM each hour was ran. It will be able to bring up all faults that it has had in the past and any faults that are current. I know that you are probably looking for a quick, easy fix but for this problem I dont think that there is any way around taking the engine in. For what it is worth, if they charge you for more than 2 hours to run it on the computer then take it somewhere else. I can fully test the engine with the computer in about an hour. The only reason that it would take any longer is if they had to put it in the water to duplicate the problem but most shops will have a test tank that is capable of running your engine under a load at full throttle. Sorry for the bad news but I cant think of any other way and throwing new parts at it is just going to get expensive quick.
SOURCE: l50deto 2 stroke outboard stalling at high revs
fuel pump could be the cause but also the float in the carby could be not set at the right level and starve the motor at high revs .
Testimonial: "I found the solution, carbs werent clean enough. Got a compressor in there and solved it. Thanks anyway"
SOURCE: skipping, lack of power, 4 stroke mercruiser
has your boat been sitting more than 60 days. ethanol gas has been proven to only stay stable for 30 days in 90 degree + weather. Labor cost can be up to $100.00 per hour. CHEAP TEST- compression, spark, and fuel. TOOLS(1) A compression gauge (2) a spark gap tester.(3) A Clymer service manual for your engine. (you can purchase from your local dealer). I know all these are expensive but if your going to be a outboard owner you will always need them. TROUBLESHOOTING (1) check compression. without the year model I'm giving you a average numbers. Look at your Clymer manual for specific numbers. all cylinders need to be over 100 lbs and equal each other within 5 lbs.(2) check spark. use a spark gap tester all cylinders should jump a half inch gap. if you have good compression and good spark, fuel is the problem nine times out of ten. Drain gas tank,clean fuel lines replace primer bulb and replace all fuel filters. Finally replace spark plugs, I know spark plugs probably don't look bad but this is a outboard. Fresh spark plugs means less resistance for the ignition system. The ignition system is week compared to automotive. Test drive boat, if the problem is still there then there is further steps to take. Again I don't know the year model so I guessing its fuel injected. Pull out your clymer manual. what is great about the Clymer Manual for Novice techs is it gives detailed info on your outboard. Troubleshooting tips and teaches you how your outboard works.
SOURCE: i have a yamaha 2
On the tachometer back you have secured a wire thread just like the one from the brakes of a bicycle. The other end of the wire is secure to the engine. This wire complete, need to be replaced. As a test first disconnect it from the tachometer and see if ok if not then the problem is with tachometer.
141 views
Usually answered in minutes!
×