Is it normal for Merc 3L I/O to run on when turned off?

[csanna]

Re: Is it normal for Merc 3L I/O to run on when turned off?

whats wrong with killing the motor in drive (low rpms coming off plane ect.) move back to neutral then turn key and away you go!<br /><br />I work on cars all day everyday. Its either a hot spot, advanced timing and or overheating.<br /><br />One sure way to make it stop is to replace the mechanical fuel pump with an electric one.<br /><br />Key is off motor wont run! \\(",")//

 

[outboardguy]

Re: Is it normal for Merc 3L I/O to run on when turned off?

Csanna, If you kill the motor in drive there is a possibility the the extra load just might make the engine run backward, therefore sucking water out of the lake into your engine via the exhaust pipe. <br />If you replace the mechanical pump with an electric it still won't solve the problem as the engine will run on as long as there is enough fuel in the float bowl.<br />Canadian, I'd stick with the majority here, lower idle, let motor cool, check timing, etc

 

[P.V.]

Re: Is it normal for Merc 3L I/O to run on when turned off?

I think that someone (Merc dealer, for one) is not reading the service bulletin fully!!!!! Yes, it says, fuel, prolong'd idling, etc... but it also references to proper throttle/carb idle settings (mixture and rpms), timing, temp (colder thermostat), spark plugs, if the dealer doesn't know the answer to this question then he doesn't know jack and cares not to find out/help!! Shame on him!!!! Find another!!!

 

[chrisg]

Re: Is it normal for Merc 3L I/O to run on when turned off?

Thanks all for your responces. ( Not sure about the cheap boat thing, mine has prases from my skier buddies, they like the way it pulls out of the hole, and has little wake (Relatively speaking, and is stable in corners and with waves, works fine for me)<br /><br />As for an update: took it to a different marina ( on the water) The idle was high, as someone above pointed out. He also adjusted the timing. Had the boat doing 60MPH with 2 people in it! backed it down abit - top being 55mph). He also got my speedo to work again. (plugged tube). It now turns off with little or no run-on.<br /><br />Have to test it with pulling the 8ft diameter tube and kids! I'm also going to tell my co-workers who have the same boat.<br /><br />Thanks all again, This is a great forum! now I got my boat working, the jetski works, now to move onto other repairs!

 

[Trent]

Re: Is it normal for Merc 3L I/O to run on when turned off?

A 3.0 doing 55mph?? Man I want to see this. My bet is your speedo is wrong. Bet its going around 40-45 wide open. Check it with a GPS. Glad you got it worked out.