View Full Version : Motor problem? or Normal operation?

09-13-2007, 03:14 PM
I have a well maintained 2000 PS195 w/ a Predator TBI motor.
It basically starts and runs really well with 390hrs.

It occasionally seems to run rich along with some increased white bubble wake trail. I say its running rich because there is a slight smell of fuel from exhaust if turning around for rider.

Keyup fuel pressure at schreader within spec, 30 psi.
Compression at 282hrs was awesome:
202.8 Average
208.0 Max
200.0 Min
3.946% % Difference
Wires, plugs, cap, & rotor are new.
Pulled map sensor and shook all accumulated liquid out of it, also pointed its connecting hose up so it is now "self draining". Did not replace the sensor. This "seemed" to help, but hard to tell for sure.

Can find no inline fuel filter ... have a past post on this.

Any thoughts on if i have a developing problem? Any better way for me to check the fuel side of tbi?


09-13-2007, 03:28 PM
I have a 2001 with the Predator engine, and it has a fuel filter just back from the carb on the passenger side of the engine.

09-13-2007, 04:03 PM
A Predator doesn't have a carb, but if you follow the fuel line up from the transmission area you should see the fuel filter.

09-13-2007, 04:33 PM
Honest, i have performed a very thorough search for a fuel filter external to the tank. Open to suggestions though.

09-13-2007, 05:53 PM
Try opening the gas cap and see if it gets better. If it does, the vent line is probably clogged. The 2000 usually had a second filter but some of the later ones didn't. The main one is on the bottom of the pump and it may be clogged.

You need to check the pressure at key ON, idle, 2000RPM and WOT. Key ON tells you very little. There's no demand at all, then.

Do you have two orange fuel lines or just one?

09-13-2007, 08:00 PM
Two orange lines. It seems to get fuel. Never stutters. Only seems to run/smell slightly rich. I'll check that vent, guess that could cause additional pressure.

09-13-2007, 09:00 PM
plugged fuel filters, vent lines will not cause it to run rich.
sounds like your fuel pressure is ok, TPS and the MAP sensors are the other key players in your injection system.

It would be nice to be able to monitor those 2 sensors with a meter and catch them doing something erratic.

390 hrs is low for something to be wearing out on your engine although any sensor can fail at any point. I don't like the fact that your draining the map sensor. monitor or swap it out with a known good sensor.

make sure all your engine grounds are clean and tight, battery as well.


09-13-2007, 09:47 PM
A clogged vent causes a partial vacuum in the tank, making it hard for the gas to be delivered properly, especially with a carb or lower pressure pump.

TPS glitches are usually way too fast to see on a meter, but the ECM can sometimes pick it up, throwing a code, either high or low. Anyone have a 2 gig digital storage scope handy? That's about the only way to see it, really.

OK, now that we have a common issue with no apparent cause, clean the flame arrestor. If I find out it's the reason it runs this way and smells rich, I'm comin' down there!

09-13-2007, 10:50 PM
Close call ... but I have sprayed it twice w/ carb cleaner. This seems like a part that can be more clogged than it looks.

09-13-2007, 11:07 PM
How much gas was in the MAP sensor? It's really not made to get any in it.

09-14-2007, 08:15 AM
It was not full, but did have some liquid, maybe one or (two small) drops total.

09-14-2007, 06:58 PM
Should i try replacing MAP sensor?

09-14-2007, 08:11 PM
I would suspect that the MAP sensor will fail fairly soon if you don't. I haven't seen many last long when they have had gas in them. Not that I'm trying to spend your money but if it was my boat, I would replace it.

If my truck somehow got gas in the MAP sensor, I would expect it to act up but if at all possible, have the boat hooked up to a diagnostic computer (MC dealer), have them grab the full sheet of data and write it down or print it from the screen (if it's done with a PC). Also, do the fuel pressure test, compression/vacuum/leakdown tests so you'll have a benchmark when it's running right. If anything is drastically different later, it'll be a pointer to the problem.

ProTour X9
09-14-2007, 08:46 PM
sorry I got nothin............breath through your mouth maybe :D J/K