November 2022 Update on the Poor Running Optimax EngineThe fix to fuel hose on the fuel tank produced immediate improvement. [The old fuel hose] must have been allowing air into the fuel system.
The [OptiMax 200-HP engine] was run at an engine speed of 4,800 to 5,000-RPM for over 30-minutes. The sea state in this run was rough chop.
I thought the solution had been found, but only at the very end of the ride to the ramp did [the OptiMax 200-HP engine] again begin to run poorly. This was most frustrating. This outing was the last time I was able to run the boat [in 2022] prior to putting it into winter storage.
In Spring 2023 I plan to accomplish the following
- install a new diaphragm kit on the fuel lift pump
- open and clean the vapor separator tank [VST]
- test the pumps
- clean filters on pumps
- replace the needle valve in the VST (which was mentioned elsewhere as causing problems)
- replace the section of gray fuel hose from the primer bulb to the engine
Replacement of the gray fuel hose should be done in case there is any varnish or debris buildup in that portion of hose.
Completing these remaining small items should culminate any do-it-yourself-overhaul of this Mercury OptiMax 200-HP engine since I bought it [as a used] engine in 2021.
I will feel more confident with this Mercury Optimax engine after these maintenance tasks are completed
More options to cure the problem of poor running on the Mercury OptiMax 200-HP engine:
- [service or repair or replace] the air compressor
- clean the injectors
- clean the fuel rails
- replace the trim relay.
I am trying to avoid those repairs due to their cost
[The problems with the Mercury OptiMax engine running poorling at high engine speeds have been] really frustrating. The 2001 VENTURA 21 boat is dry and in great condition. At full throttle the boat is a ton of fun.
I expected to [need to perform] most of these 300-hour-type hour maintenance services when I bought this boat in September 2021.
I really don't feel like the Mercury OptiMax engine is failing. On the report from the engine control module there are no faults and 480-hours of run time. [Maintenance on this] Mercury OptiMax engine was a bit neglected. The simple upkeep should resolve these running problems.
In 2021 when I purchased the boat, I did plan to re-power in the future, but not so soon as 2022.
In Spring 2023 I will give more updates after I have completed the maintenance of the fuel system.
[Problems with engines running poorly at high engine speeds are] part of the fun of buying a 20-year-old engine. To tinker with the engine is fun.