View Full Version : 1998 SportStar 305 TBI Stalling help

05-05-2011, 08:15 AM
I am new to the forum but have read about everything I can get my hands on over the last couple years trouble shooting this problem on my Throttle Body injection 305. I am desperate to not deal with this for another season. I have attached an word document with timeline and brief explanation of what has transpired over the last 4-5 years. Yes 4-5 years of attempting to remedy this headache.

A brief overview of what is currently happening is as follows: The boat starts perfect and runs smooth as silk for about 7-10min. While running between 4-4500rpms the engine rolls back and surges between 600-1800 rpm, regardless of throttle position, then after 3-4 cycles of surging it dies. After 5-7 attempts to restart the motor, (It starts runs for a couple of seconds then quits again) it stays running and I have no more problems for the rest of the day. I have only run it for about 25 min after the initial shut down and I have stopped and restarted it multiple times with no issues.


06-14-2011, 07:33 AM
For those of you that read this, I went back to Indmar and worked through the electrical diagrams to see what was causing the ECM to put the boat in to "reduce power" mode. Then my dealer cleared out he ECM codes and this time there was 1 for the MAP sensor voltage. Upon clearing the code the boat ran fine for 30-40 min. Then the same problem arose. Finally I hooked up a voltage meter to the alternator to see what that was putting out. When the boat would falter the regulator was spiking from 13.8 to 16-17 volts. I had a local shop rebuild the alternator and now the boat runs perfect. All this time it was a intermittent alternator. I hope this helps someone else in the future.

06-14-2011, 07:49 AM
Thanks for sharing your information. I'm sure it will help someone down the road, or lake.

Welcome to TT!

06-14-2011, 08:14 AM
An alternator going tilt once in a while is not one you are going to see often. Great job working through the problem.