2003 MerCruiser 135 I/O, Sluggish, Sputtering, RPM's

[03glastron]

Hello all, I will start off by saying that I am new to boating and recently purchased my first boat. Please forgive me for asking what may appear to be "Gomer" questions. With that said, I have a few questions regarding my MerCruiser 135 I/O. I am assuming the motor is a 2003, being as the boat is a 2003. Here are my questions/concerns:

1. When cruising along at about 32 MPH, my RPM's are almost at 5,000. This is with the trim all the way down. Is this a problem? If so, what can I , or should I do differently?

2. A lot of times when I shut the boat off it sputters/chokes and doesn't shut off right away. I have only seen this happen on older carburated vehicles. I have been told to use higher octane fuel as a way to prevent this from happening; however, that still doesnt always do the trick. I have also been told to let the engine idle down for about 60 second before shutting it off. That usually does the trick; however, sometimes it still does it, just not as bad. What could be causing this?

3. I have also noticed here recently that when taking off with a skiier, when pegging the throttle to get them out of the water, the motor is very sluggish and falls on it's face. It's not a problem if I slowly accellerate, only when I give it too much at once. What could the problem be?

 

[Bondo]

Re: 2003 MerCruiser 135 I/O, Sluggish, Sputtering, RPM's

Ayuh,....

1),.. Trim it Up some.....

2),.. Do a Tune Up,+ Service,.... No it Shouldn't be dieseling,... That'll Kill your motor....

3),.. Change the Fuel Filters,.. If that doesn't fix it,... Rebuild the Carb.....

 

[Don S]

Re: 2003 MerCruiser 135 I/O, Sluggish, Sputtering, RPM's

Read post #5 in the thread below.

http://forums.iboats.com/showthread.php?t=50502

 

[03glastron]

Re: 2003 MerCruiser 135 I/O, Sluggish, Sputtering, RPM's

Thanks for the replies. I am dropping my boat of tomorrow morning to a boat mechanic that was recommended to me. I am having a tune-up done, to include having timing checked and set, plugs, wires, etc. I have decided to try and change the fuel filter first before spending the cash for a rebuilt or new carb. I will be out on the lake all next week so i'll post an update after that to let everyone know if that fixed my problems. Thanks again.

 

[03glastron]

Re: 2003 MerCruiser 135 I/O, Sluggish, Sputtering, RPM's

PROBLEM SOLVED!!!!!!

I picked my boat up from my boat mechanic yesterday and took it out this evening for a test run. All issues have been resolved with a simple tune-up.

Prior to the tune-up, my MerCruiser 3.0 idled at about 1000 RPMs, which I didn't know was a big deal. I was also told my timing was off by about 2 (whatever that means). The cap was showing signs of corrosion. Plugs looked good but were changed anyways. Timing and idle were adjusted to where they should be and all is well. My mechanic said he didn't see any reason to change the fuel filter......so far, so good.

Just thought I would post an update in the event any other newbies had similar problems. Thanks to those who responded to my original post.

P.S., It sure pays to know a guy who knows a guy who knows a thing or two about I/O's. A local boat dealer wanted $200 to shake my hand, put my boat in the bay, and diagnose the problem. Then they were going to charge me parts for whatever they deemed needed fixed plus labor. I got off easy - $99 to fix my problems. Thanks again!