Info Merc Opti 150

[willy]

If the motor on that V21 had a JohnnyRude or Yammi or even a Zuki I would have taken it home today

[cterrebonne]

willy there was an update kit that included all new injectors and new thermostats. the inj should be blue and the t stats should be 160's if i remember correctly. like ferm said if the air motor goes out it can cost but when they go out it is pretty obvious and you can replace it your self. the key is keeping the air pump cool and lubed.

[willy]

CT if you are talking about a color you can see on the outside from what i can remember they were all basically black I believe.
Do you guys run Optis, have they been good for you?

[cterrebonne]

Originally Posted by willy

CT if you are talking about a color you can see on the outside from what i can remember they were all basically black I believe.
Do you guys run Optis, have they been good for you?

yeah it probably did get the update kit, because i think both the 2.5's and 3.0's used the same update kit. i never owned one but ran several as a tech. they really are easy engines to work on and diagnose. you only need a mercury DDT to help with dropping cylinders and testing tps voltage but major stuff like air pump locking up and belts snapping are easy fixes. the worst part on those engines are changing the plugs. they are like all of the older DI engines either they run forever or you have to rebuild them at least once. when i worked on them i really didnt see a whole lot of burn ups but i saw many comps go down mostly due to overheating the pump, which the ddt will tell. plus side on them are they sip fuel and will spank any 4 stroke on economy and the lower units are very solid. just make sure you use a oil which is a clean oil, fully syn because plugs are around 15-18 a piece and cleaning the carbon off the injectors is rather a pain.

[THEFERMANATOR]

MERCURY recently released a bulletin to run ONLY MERCURY DFI oil in the OPTI's. they felt alot of the early failures were due to standard TCW-3 oil not lubricating properly. So rmember that your looking at about $30 a gallon for oil. Spark plugs from MERCURY are $21 EACH, but they say you can order them from an auto parts store for $7. The OPTI's are the BEST for fuel economy right now outing the ETECs and the 4 strokers. The older FICHTS were actually on par with the OPTI's for fuel usage. The injectors in 01 were the cause of the OPTIMAX's getting the OPTIPOP name, or the OPTICRAP. There was an update, and I want to say the injectors should be blue as well, the black and red ones were the bad ones IIRC. I don't think a DFI is for me, I like being able to fix them myself with a timing light and a PRV. Not a laptop and RINDA or a DDT.

[spareparts]

I've never owned an DFI engine, I've ran more than my share, and I personally like the OPTI's. I have yet to run an engine that sipped fuel like an OPTI(no, I have put in enough time on an e-tec to have an opinion). I've allways prefered Mercury V6's over the compition, you can't beat the hp to weight(e-tec excluded). Around here everybody wants Yamaha, so I hear all the "horror stories about Merc's" . Excluding the injector issues, the biggest problems I've seen with the OPTI's ( and with HPDI's) is carbon build up casuing burnt pistons. Carbon will create a hot spot on the piston as well as increase the compresion ratio to above normal from build up in the combusiton chamber. The number one cause of this is using cheap oil. I could never figure why anyone would spend $10,000 on an engine, then pour $12 a gal oil into it, then complain that it blew up. Combine cheap oil with all day of slow trolling, that after the boat was run out to the fishing spot over loaded because it was propped out for a light load. And any motor will scatter. Using "ring free" or carbon guard in every tank, allong with using DFI specific oil will aleviate most DFI issues. Bomb had a good idea in offering their 100 to 1 oil, no one has a cheap version, so every one has to run the good stuff. AFter having to run higher priced oil, and fuel additive, it eats into the fuel savings.

After all this being said, due to the high price of parts for any DFI engine, I wouldn't own one thats wasn't under some kind of factory warranty. Older DFI engines(HPDI included) don't have any resale around here. Allong with the aircompressor failure being expensive, price out the fuel regualtor rail assembly at over $800. There is a lot of planned obsolecence into these motors. I'll stick with good old sloppy carb motors that i can rebuild the entire power head for less than the price of the outside accesories bolted onto the block

[Airslot]

Willy,

If you do any reading on THT, the OPTI's have the best rep of any of the DFI engines over there. They do like a fully charged battery. I've been able to run a pair of 225's for quite a few hours. For what its worth, I WAS planning on hanging a 150 OPTI on mine this summer. Looks like I may have to wait until spring...