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I've read through a hundred hours of forum questions over the past 2 summers. Lots of problems sound similar but I've replaced all the items that solved their issues to no avail. I have owned the boat for 11 years and never had an issue until 3 years ago when we had a couple trans bolts break that were repaired. Then beginning of summer last year the engine problems began. Many new parts and 2 dealers/mechanics later and no resolution (one is a Mastercraft dealer and the other is a former Malibu dealer). Both have lots of experience with this/similar motor. Boat idles rough (started when issues started) but runs great after throttling up for 2-3 minutes until it reaches temperature (160). After about a minute it falters then loses power. RPM's surge, boat continues to move but with almost no power that continues to fade. Move to neutral and it resets. Boat runs great for about 20 seconds and all repeats. I can do the neutral reset a 100 times and it never changes. The dealers have not been able to duplicate the fail while in the shop. It went to the MC dealer 1st because he is closest to my house: they said the ECM was bad and needed to be repaired. Sent it out for repair. Boat came back and ran for about 4 hours and then failed. After 6 weeks of them not giving my boat attention I took the boat back. Then it went to the Malibu dealer that has serviced/winterized it for me the past 11 years. This is what the former Malibu dealer detailed for me; We found a bad ground last year (19') in the motor and fixed. Motor ran well after that for a couple of hours and then failed and wouldn't start/run. Then we changed the complete distributor because we had no spark. Boat would start and run but then the original power failure returned. Then we changed the distributor again because the motor had no spark again and we found the module in the distributor bad so we changed. The last time in we found the distributor module bad again and changed. Also checked all the power wires and grounds and found one of the grounds going into the ECM to be bad. Repaired but are questioning, since day 1, the ECM rebuild that the other dealer had done. When we hook either my Rinda hand held or Laptop I often can’t get a connection to ECM. Motor also doesn’t run well at idle compared to other like motors. We are at a loss. Here is what has been done, checked, replaced. ECU was sent out for a rebuild Fuel filter replaced Fuel pump replaced Fuel pressure regulator replaced Fuel injectors professionally cleaned and tested Fuel pressure is solid at 44 psi even when boat is failing. MAF replaced TPS replaced New gasket on air intake New distributor Plugs Wires Any thoughts on this would be helpful.

Hi crew, im about to embark on a damper plate replacement on 2002 vlx wakesetter Vdrive with a monsoon 335. If anyone has any detailed guides with photos specific to a vdrive it would be much appreciated.

Hello, I hope someone can help troubleshoot before the summer is over, our summers are short here in Massachusetts. I have a 2003 response lxi with a monsoon 335. Engine starts up ok. Idle is decent sounding. Moving forward, there is loss of power. Opening up throttle will only get up to about 2,000 rpms and 20 mph maximum. And it is slow getting there. When I rev it in neutral. It will go to high rpms, but when I pull back the throttle to neutral it sometimes stalls. The air intake gives a hissing sound more than normal when changing to forward, or throttle coming back down to neutral. here is what I’ve checked so far: fuel pressure is 40 at neutral and 48 when trying to move forward. Changed fuel filter. Put additives in fuel, star tron, stab il, sea foam. Changed MAP sensor, ITC sensor, water temp sensor. Unplugged oil pressure sensor (forward going to gauge) and pointing port side. Runs same with either disconnected. Oil pressure reads 20 when idle, goes to 40 when underway. Temperature gauge reads 160. Checked timing, it’s 20. Changed spark plugs, cap and rotor. A few years ago the alarm started sounding under the dash. Sounding all the time. The engine was running perfect and gauges were reading normal. So I disconnected the alarm. It ran for a few years after that running perfect. Until now.