Running Rich? Loads-Up at Take-off

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   1994 Ski Nautique O/B.  5.8 Pro Boss - throttle body fuel injection.

For the last 6 months or so, the boat seems to "load up" when I'm idling and waiting for the skier.  If I go from idle to W-O-T to pull up a skier, the boat seems to bog down at take off.  After the RPMs run up, the boat takes off like a scolded dog.

One "trick" helps a little:  If I go to neutral and rev the engine a couple of times to 3,000 RPMs and then immediately engage the transmission when the RPMs come down and then take-off, the boat seems to run much better.

The engine exhaust looks a little too dark gray/black to me and my first thought is that it is running a little rich.

Any suggestions?  If it is running rich, can the TBI be adjusted?  I was a wrench-turner back in the 1970's and my experience is with wheeled vehicles and carbureted vehicles, so EFI is a little "black magic" at times.

Thanks,

JQ

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Jonny Quest Members Profile Send Private Message Find Members Posts Add to Buddy List Grand Poobah Joined: August-20-2013 Location: Utah--via Texas Status: Offline Points: 2958	Post Options Post Reply Quote Jonny Quest Report Post Thanks(0) Quote Reply Topic: Running Rich? Loads-Up at Take-off Posted: August-20-2013 at 12:57am
	1994 Ski Nautique O/B. 5.8 Pro Boss - throttle body fuel injection. For the last 6 months or so, the boat seems to "load up" when I'm idling and waiting for the skier. If I go from idle to W-O-T to pull up a skier, the boat seems to bog down at take off. After the RPMs run up, the boat takes off like a scolded dog. One "trick" helps a little: If I go to neutral and rev the engine a couple of times to 3,000 RPMs and then immediately engage the transmission when the RPMs come down and then take-off, the boat seems to run much better. The engine exhaust looks a little too dark gray/black to me and my first thought is that it is running a little rich. Any suggestions? If it is running rich, can the TBI be adjusted? I was a wrench-turner back in the 1970's and my experience is with wheeled vehicles and carbureted vehicles, so EFI is a little "black magic" at times. Thanks, JQ
	Current 2003 Ski Nautique 206 Limited Previous 2001 Ski Nautique Open Bow 1994 Ski Nautique Open Bow Aqua skiing, ergo sum

Bri892001 Members Profile Send Private Message Find Members Posts Add to Buddy List Grand Poobah Joined: September-27-2008 Location: Boston MA Status: Offline Points: 4947	Post Options Post Reply Quote Bri892001 Report Post Thanks(0) Quote Reply Posted: August-20-2013 at 12:49pm
	Your TBI should have an actual injector that is squirting into the throttle body. My only suggestion is that maybe this is hanging open or is gunked up somehow. Maybe gas is just dribbling in and not spraying in nice like it should. Unless this injector corresponds to another one in the automotive or marine world, your choices could be kinda slim. Of course, maybe it could be cleaned somehow as well with a fuel tank additive etc.

Jonny Quest Members Profile Send Private Message Find Members Posts Add to Buddy List Grand Poobah Joined: August-20-2013 Location: Utah--via Texas Status: Offline Points: 2958	Post Options Post Reply Quote Jonny Quest Report Post Thanks(0) Quote Reply Posted: August-20-2013 at 5:59pm
	Yea, clogged fuel atomizers was my first thought. I've run several fuel additives through (Lucas, Sea-Foam). No help. My sense is that the fuel atomizers are just getting old. From what I can see, the options to repair are pretty slim as parts appear to be hard to come by. I may just opt to convert to Mallory ignition and carburetor. JQ
	Current 2003 Ski Nautique 206 Limited Previous 2001 Ski Nautique Open Bow 1994 Ski Nautique Open Bow Aqua skiing, ergo sum

Dreaming Members Profile Send Private Message Find Members Posts Add to Buddy List Platinum Member Joined: May-21-2010 Location: Tacoma, WA Status: Offline Points: 1870	Post Options Post Reply Quote Dreaming Report Post Thanks(0) Quote Reply Posted: August-21-2013 at 12:07am
	JQ, have you checked your fuel pressure? if it is low, the injectors would not atomize correctly. I have a pro boss that I am working on, and might be interested in your electric fuel pump arrangement if they work and you do decide to swap out for a carb.

Running Rich? Loads-Up at Take-off

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