225 Optimax opinions

[jasoncooperpcola]

Just talked with the gentleman with the 1994 Merc 2.5L 200. He said he has had it out about a dozen times, but needed a short shaft motor. It needs a cowling seal, the po took it out. He said he is willing to let me do a comp check. What all do i need to lookout for on this motor? What should my comp numbers be? Going to look at it saturday.

[THEFERMANATOR]

Compression should be around 120-130 for a 2.5L I believe. The only real downfall to them is the oil injection system, and the power packs for the ignition. Other than that they are strong reliable engines.

[jasoncooperpcola]

Should i plan on running premix or can i trust the oil injection if i replace major components? What should i be reading at the plug leads with a multimeter? Will Mercury new gauges work with it?

Also i might take what is left of the loan and get a Mercury 2 stroke kicker. Thinking 15-25hp 20" shaft.

[phatdaddy]

there are 2 different schools of thought on the oil injection system. i have a 94 150 with 1500 hours, all on the injection system. it is a simple pump system that works off of a plastic ring on the crank shaft. if that ring breaks, pump no pump, engine no go. the only alarms on it are one on the pump that will sound if the pump quits rotating and another in the engine mounted tank that sounds if it runs low on oil. i have friends with the same motor that they have disabled the system. they use a lot more oil and have to clean carbs more often. i have never had the carbs off of mine. one day, i am going to get snake bit, but for now i like the system. i do carry a spare gallon of oil and at the slightest hint of a buzzer , i dump a gallon in the fuel tank. i have only had to do this once in 18 years because a hose split & the top tank was not refilling. the oil is moved from the storage tank to the motor tank by crankcase pressure. i do keep a eye on my hoses and have replaced them twice. to change out that ring, you have to take the whole motor apart.
i am sure 80% on here will tell you to run premix to eliminate a varible.
also make sure the steering arm is in good shape, mine almost rotted off and a major pia to swap out.

[spareparts]

steering arm is the big issue, make sure its not rusted real bad, it would cost around $1500 to have it replaced, if it all came apart easy. I'd ditch the oil injection, if the motor was run on a regular basis, I wouldn't worry about it, most of the gear failures I've seen are from engines that sat a lot, if you want to gamble with it, mix some amsoil 100 to 1 oil at about a 200 to 1 ratio, if the gear dies, you have some lube in the gas to prevent immediate failure, then add oil to get you home

[jasoncooperpcola]

It would be nice not to have to premix, but if oil is in the fuel tank then i know its there. I think i found the oil pump gear, its called a "gear kit" on the crankshaft and is $40 but dam Phat was right you have to disassemble the entire powerhead. You would think there would be some way to retrofit a new oil pump onto the flywheel or something. I dont even know if the oil pump is hooked up or not. But i plan to have a premixed 6 gallons of fuel.

I learned from the Johnson to check the steering shaft etc.

[spareparts]

good luck finding one(2.5 200), seems like the price on the newer four strokes have driven the price on good used two strokes up. Look on craigslist cities around big fresh water lakes. I've been looking for a 200 for a friend of mine, found a bunch of 150's, even a 175, but 200's are getting hard to find. The 225 Opti seems to be the most common used engine for a decent deal, you just have to deal with the weight

[captpete13]

Originally Posted by jasoncooperpcola

It would be nice not to have to premix, but if oil is in the fuel tank then i know its there. I think i found the oil pump gear, its called a "gear kit" on the crankshaft and is $40 but dam Phat was right you have to disassemble the entire powerhead. You would think there would be some way to retrofit a new oil pump onto the flywheel or something. I dont even know if the oil pump is hooked up or not. But i plan to have a premixed 6 gallons of fuel.

I learned from the Johnson to check the steering shaft etc.

a couple months ago I installed an electric oil pump conversion for a 2.5 merc. It uses an electric motor to run the merc mechanical pump. It all fit under the cowl with no real modification to the engine. When I go to work on Monday will try to find the papers for it.