17
Nov
It accelerates and cruises just fine up to this rpm but attempting to accelerate beyond this rpm results in the engine sounding like its hesitating or misfiring and fluctuating between about 4400 and 4800 rpm. The compression is 90 lbs in both cylinders.
When an outboard motor runs at speed but cannot hold an idle it usually indicates a problem with the carburetor.
Outboard running rough at low speed. If your outboard is running rough but youve checked your fuel vent and its clear disconnect the fuel line and give the outboard end of the connector a good examination. If it appears OK inside but the outside is corroded and worn consider replacing it with a new one. There may be a blockage or failure you cant see inside it.
My 1998 Yamaha 25ELRW outboard runs rough at RPM below 2200. Above that it runs smooth and has plenty of pep gets right up on plane. It starts right up but idles rough and shakes until the RPM rises above 2200.
The carburetors have been cleaned and the fuel pump was rebuilt. The compression is 90 lbs in both cylinders. Boat running rough and dieing at low speed Idle speed should be set in neutral 750-800 rpm.
If it dies when you put it in drive you need to adjust the link rod with the 2 plastic ends. Once you get it to shift into gear without dyingshut the engine off and go to full throttle position and make sure the carb shutters are level and wide open. Runs rough at low rpm - questions please.
I have a 1995 Evinrude 90 hp outboard from new. It has about 800 hours on it and last spring had a lot of work done on it primarily because it would contiue to dripooze gas when shut off. Currently it starts fine and has never failed to start.
Rough running and occasional misfires may be lean sneeze Clean carbs and do the link and sync when put back on. This include timing checks Does this motor have a chokeor is it a prime start enrichment system. Check fuel pump and thermostat simple enough to do or just replace.
Water pump kit and inspect housing to see if it needs replacing. It has roughly 190 hours on it. For a while it barely would run at all at any level of throttle as it seemed to surge and would eventually die.
After running it at around at lower rpms for a while 15-20 minutes it seemed to work itself though the worst of it. Suzuki DF300 - running rough-stumbling. Boat sat for a little longer than usual over the winter.
The first time I tried to use it this season it started fine and seemed to run ok for a few minutes but then started to stumble and surge. Then it started running really rough under load. I did drain same cloudy fuel water out.
Top tips from one of Suzukis expert engineers focussing on possible causes of your large horsepowerperformance outboard running rough and how to maintain. 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.
Mercury outboard idles rough andor stalls refers to when a Mercury outboard runs in an irregular or uneven manner while in neutral or out of gear. Have a 2000 115hp 22 mercy outboard that runs rough with some hesitation at mid range rpm. Motor runs fine at low and high speed only thing that changed was input in non ethanol premium gas and amsoil 2stroke marine oil.
Sometimes boat issues seem like theyll be really complicated but end up being easy to fix. My 2001 50hp mercury outboard at low speed skips and cuts out and then comes back motor runs fine when igive it powerit only does it when i click in gear and low speed trollingI broght it to a merc dealer and they changed the fuel line and fuel filter and primer ballthey cleaned out the fuel pump and leaned out the engine and said the motor was putting out plenty. My outboard starts fine and when i take off runs good for 15 sec then starts to bog down.
If i leave the throttle where it was full power will come and go every few sec. If i let up on throttle and idle in gear it runs fine. I take off again and same thing runs under throttle for 10 to 15 sec then starts cutting in and out.
Another possible cause is an air leak in the fuel line. When this occurs theres a constant fluctuation in the amount of fuel thats pumped to the boats carburetors and as a result the motors RPMs go up and down. Regardless of your boats throttle setting the presence of an air leak will greatly restrict its speed.
I have a 22 Hewescraft Searunner with a 2006 Yamaha F115 outboard at 1000 hrs. The motor runs rough above about 4300 rpm. It accelerates and cruises just fine up to this rpm but attempting to accelerate beyond this rpm results in the engine sounding like its hesitating or misfiring and fluctuating between about 4400 and 4800 rpm.
2006 50HP 4 stroke EFI Rough cold idle and surging and stalling at low rpm You may want to check the TPS throttle position sensor while the problem is occurring It didnt throw a code on my 115 but was out of spec while problem was occurring. When you adjust the gas intake and speed of a Johnson outboard motor youre accomplishing two tasks in one. Youre setting the motors low speed its idle speed and youre adjusting the mixture so that the motor performs at its optimum efficiency at both high and low speeds without sputtering or coughing.
Why does my outboard stall. Your outboard may be stalling running out of fuel due to three issues. Either the lift pump has failed the boat is out of fuel or there is an air leak or blockage somewhere in the fuel lines running fuel from the tank to the engine.
There are several methods to troubleshooting a stalling outboard engine. My 2005 Mercury 60-HP FOURSTROKE Bigfoot EFI outboard engine runs rough stutters quivers quakes and shimmies intermittently between 900- and 1800-RPM. At higher engine speed it runs fine.
Idle air controller has already been changed and the spark plugs were changed within 20 hours. Hi All - Appreciate all ideas on this. Im trying to troubleshoot a nasty problem on a 1999 Evinrude 70 HP Four which I understand to be same as DF70 open to someone telling me Im off on that if Im wrong.
The basic symptoms I have are difficulty with initial cold start and difficulty maintaining. When an outboard motor runs at speed but cannot hold an idle it usually indicates a problem with the carburetor. Outboard motor designs vary depending on make and model but all operate on similar principles.
Consult your owners manual to check items that may be unique to your motor. Most manuals come with a. Mercury optimax 90hp starts but runs rough at idle speed and sometimes stalls.
Will run at higher RPMs and speed. Carbs rebuilt and now its determined 2 valve is leaking a bit of fuel–it runs rough at low idle but does run. 11 years experience working on outboards inboards sterndrives pwcs.