Re: Surging Optimax 1999 200hp
Call 1-920-929-5000. Have your engine serial # at the ready. This is Merc corporate customer service. The rep will be able to tell you right then and there exactly what the Merc Corporate computer has on file in regards to your specific engine's serial # as to ECs and if they are all shown in their system as having been completed. If the rep confirms all ECs have indeed been done then you should explain the situation and request that a corporate rep take a ride on your boat with you to help resolve the issue since you have made more than a fair effort thru the dealer channels without success. Confirmation of the ECs not having been done would clue you in that you are being mistreated at the dealer level. The Merc rep will bring along the DDT (laptop for diagnostics) and the pressure checking tool for fuel and compressed air pressures. If you are unsatisfied with the support at this phone number (they refuse to set you up with a corporate rep visit), call 1-920-929-5512 which is the first line manager of Corporate Customer Service, Mike Butler. You might also harass one of the dealers to send out a rep with a DDT and go for a ride. Under warranty, or not, corporate Merc will take efforts to achieve and maintain a satisfied customer. The early Optimax 3 liter blocks had a lot of problems with fouling spark plugs and grenading power heads. With a 1999 you really might want to consider taking a loss and getting out from under that motor for a brand new 2006/2007 as they were still cutting ECs on the 2004/2005 related to loosing compression on some of the engines on cylinder #6. Even the vertical drive itself has had several ECs since then. One was for the seal on the shift shaft. The seal would sometimes pop up from pressure in the gear case and allow water into the lower unit. In later years this seal was "captured" by a flange to prevent the problem. This would also cause some momentary hi temp alarms for a few seconds after a warm restart because the water had another path to go into initially upon restart. This did not effect the "at speed" running temps but did , of course, fill the lower unit with water. The plugs you are using are the Iridiums. These are the best. Another typical check done on these motors is a simple device is hooked up to the two Schrader valves. One valve is the hi pressure fuel output and the other is the compressed air. These must maintain a 10 PSI delta, the fuel being the higher amount. You can check yourself if you simply rig something up thru the Schrader valves. You should see 90 psi fuel and 80 psi air. There is a "tracker valve" that assures this delta of 10 psi. Perhaps at part throttle there is an issue here. Let us know how you make out with the corporate Merc customer service team.