Og743300 98 optimax 225. Last time is was a reed broken. Now I have cylinder 4 not working. Engine sputters and bounces until I unplug number 4 cylinder. I did get a record 6 fishing trips since my last breakdown. Just wanted to vent. BTW I have changed plugs and coils still no change. Plug comes out soaking wet. Maybe stuck injector flooding the cylinder I dunno. I'm bout ready to see this opti hit the junk pile and repower
Have you had the engine for the entire 19 years?
This motor has had several issues before, with a donor motor being used for replacement parts.......Originally Posted by Mark Weare
Well just fixed it. Lost a air pressure diaphragm. I have used my last spare. Looks like I'm off to the junkyard to try and find another spare. Correct me if I'm wrong here......the only way to get one is to have one made right???
Bought it last October from an old man. Had low hours so I wasn't scared of it. I have since regretted my purchase. Seems like a constant issue. But she is running again. Let's see how long before my next issue!!!..lol. I'm afraid to take it out in fear of a breakdown. On the bright side so far it's all been simple stuff. No big faI lures yet thank god
That is the first year of the Optimax. Those had a lot of issues. Newer ones are better but still have weaknesses. I have had three with relatively few issuse. Biggest was a blown compressor covered under warranty.
I just hope some day there is a whole line of four stoke (non Verado) motors feom 175-250!
USN Retired
2020 Basscat Caracal
2020 Mercury 225 ProXS 4s
That year model is what gave them the Opti-Pop name.
You can purchase the air/fuel regulators diaphragms by themselves. 8M6002988
Tracker Valves can also be purchased 804533
You really need to get a professional set of eyes of the motor in my opinion. Repetitive failures of any one item is almost never a coincidence but rather an underlying problem that is destined to cause repeat failures and running problems until addressed.
As stated, fuel and air regulators are not plug and play. There is an adjustment screw that has to be accessed then calibrated by someone that has the tools and knows what they are doing.
My Optimax is a 2001 225 and I have had minimal problems. Low Pressure fuel pump (sat for a while) thermostats (fouled them by running in sand) and generalized maintenance.
They are great motors when properly maintained and fixed correctly.
2001 Mercury Optimax 225
0T344965
2000 Mercury ELPTO 125
0T072885
My brother got twin 250's when they first came out. He had lots of issues. They were constantly getting fixed. When I was getting my 1st Bassboat in 2005 he told me to get an Optimax. I said you've had nothing but trouble? He told me he got originals. They got the bugs out nowAnd all issues were fixed by the dealer even after the warranty expired. I'm on my 2nd boat with a Optimax. Nothing but scheduled maintenance. Love my motor! Boat not so much
2012 Ranger Z119 Mercury 200 Pro XS
When only a diaphragm is changed there is no need to calibrate the housing. I have done extensive studying on my engin and nothing I have done calls for calibration. The diaphragms I used were from an older motor so I'm confident that's why it failed. This is the first time I had this exact one fail. First it was the tracker then a broke reed now the air pressure diaphragm. I have done all my own work simply because NOONE in my area can work on these motors RIGHT. Yes Don can but he is 3 hours away and has a 2 to 3 week wait. I hAve gotten to wheree I can lisiten to my engine and figure out what's wrong with it. My local marina Gave me a merc patch and said I should be certified by now cause they were lost when I had my reed issue..lol
I drive 3 hours to Don. It is worth the drive!
USN Retired
2020 Basscat Caracal
2020 Mercury 225 ProXS 4s
As long as you have access to parts you should be fine then.
2001 Mercury Optimax 225
0T344965
2000 Mercury ELPTO 125
0T072885
Tracker valve doesnt need calibrated but fuel pressure regulator diaphragm might
In 2003 my mechanic told me to not buy one so I got a 200 hp EFI MERCURY. He said it was bullet proof and still seems to be true. I have seen lots of Optimax units in the corner of various shops with the head off waiting for parts.
I still have to politely disagree. The housing is where the calibration happens. Changing only the diaphragm makes no changes to the calibration. If the pressures are off then yes maybe calibration is needed. The calibration of these parts is not as complicated as it may seem either. But I still say that changing only the diaphragm has 0 effect on the calibration. I may be wrong but I can say 100% that on a 98 opti 225, no calibration is needed. I changed diaphragm yesterday and motor runs great now with pressure exactly as it was with original diaphragm
The calibration can change with a diaphragm change due to the membranes make-up. Yours is working because your luckily staying "in the window". If you had the pressures calibrated your motor could run even cleaner, and better, than a old motor could run.
The diaphragms im using are the older green ones. The difference in the makeup of the rubber, even if different by a small amount, would only effect pressure by a minuscule amount. maybe im missing something here but I just can't see how the diaphragms can make that much of a difference. the motor runs super after I replaced the broken diaphragm. I can't help but think these motors are not as complicated as some think. At first I was lost on diagnosing it but with a little knowledge on engines and some studying in have found that its really not that bad of a motor to work on. once you understand what it needs to run correctly its simple really. and even calibrating isn't rocket science. Pull the plug and tighten the screw or loosening it to get optimal pressure on the system. Proper tools would be necessary of course. I can see me being "Lucky" 3 or 4 times. during my last issue I removed all diaphragms and inspected them. I even replaced one that looked like it could fail soon. All together I have replaced all 3 with ones from 2 different motors and have not had any change in running. Perfect air and fuel pressures. Im not usually lucky at all...lol. THese things may not work like this on the newer opti. my 98 is way WAY different from the 05 parts motor I have. only some things are the same. maybe im very very very lucky but I doubt it. Im not trying to upset anyone just stating MY experience with MY motor. to each there own I guess.
The ONLY way to calibrate a fuel or air regulator is to drill out the freeze plugs on the housing and give it pressure by screwing in or take away pressure by backing off in a screw that will strip even with the best tools
That's kinda what I said...lol. the screw simply tightens the spring or loosens it to in tease or decrease the pressure. That's why I said proper tools would be needed. It's not rocket science just more than the average guy would be willing to do. I like working on my own stuff and saving the thousands of dollars a shop would charge. So far I have already saved a ton with what I have learned. Now when it starts acting up I know exactly what to look for. I have never owned a boat motor than acted up so often. Even with used parts it should do a lil better than its doing!! IM surprised this thread is lasting this long. I figured ppl would get upset beca use I bad mouthed an opti...lol
[QUOTE=ncshooter;8436181! IM surprised this thread is lasting this long. I figured ppl would get upset beca use I bad mouthed an opti...lol[/QUOTE]
It has happened in the past. Ask me how I know
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