Mariner EFI 150 rebuild question.

[hooken203]

1997 Mariner 150 EFI #0G508602
I bought this engine with one cylinder low on compression. #1 cylinder scored but not to bad.
I now have it disassembled and have a couple concerns. The grooves in the block where the crankshaft sealing rings run looks to be normal wear but at what point is it excessive and how would you deal with it?
I have read the post about getting rid of the oil injection system and I would rather not do that. The system got it to the point of being more than 20 years old. So should I replace a 20 year old oil pump or figure it’s not a big wear item and continue on with the original one?

[leonreno]

No idea about the crankshaft seal wear but I would replace/rebuild the oil pump and replace the gear on he crankshaft that runs the pump.

[luvdmymerc]

I agree with leonreno, if you already have it torn down, it would be silly to put it back together without replacing the nylon grear that drives the oil pump.

[hooken203]

#1 cylinder is scored its not bad because as soon as it lost power the guy shut it off and never started it again. I think it was getting hot water pump was ugly. Yes I am going to have it bored .015 over. I know its hard to tell with out seeing the groves. I just wonder what other peoples experiences were.

[JOE54]

the grooves in the cyl blck caused by seal rings are not a problem unless a new crank is installed and new seal rings do not line up or fit block, never had a problem with seal rings out of literaly hundreds of repaired engines , replace the gear on crank

[hooken203]

Thanks Joe

[Have rod will travel]

Like pointed out, fix all. And on top of that, that engine was made before the restrictions took place. If it were me, I would add the parts needed to get it up to 200hp.

[OnTRAK]

Like pointed out, fix all. And on top of that, that engine was made before the restrictions took place. If it were me, I would add the parts needed to get it up to 200hp.

You can't get the 150 up to 200hp just by adding parts. The block porting in a 200 is different from that of a 150. The part needed would be a complete 200hp powerhead.

[Have rod will travel]

You can't get the 150 up to 200hp just by adding parts. The block porting in a 200 is different from that of a 150. The part needed would be a complete 200hp powerhead.

Not going to argue with you because you probably know more about it than I do. But some years ago in a boating mag they said the 150 is a detuned 200. They even gave a list of items that would be needed to get it up to 200. And if I remember correctly it did involve taking the engine apart. My thinking at the time if I ever needed my engine rebuilt, I would spend the bucks and get it boosted to 200hp. I think I saved the article, and if I can find it, I will post it. So, again if I or anybody has the engine torn down, I would be something to think about.

[Have rod will travel]

If I remember correctly the mag was Bass and Walleye boats. Great mag. I may still have the issue in the bsmt, but if not, I will look in their archives.

[OnTRAK]

No problem. I'd be interested to know what you find out if you find the article. It's not impossible. You could have the ports of the 150 block ground to the specs of the 200hp block (it's expensive and run the risk of ruining the block if not done correctly) and change over to the 200 electronics and fuel system, but it would be a lot easier, less expensive, and more efficient to just change over to a 200hp drop on powerhead. Probably the best bang for the buck on the 150 would be to have the heads cut by Jay Smith, add a set of fiber reeds, maybe a set of Chris Carson's reed block stuffers, add a Bob's or a 2.4 liter 200hp bell exhaust tuner (not much to be gained from the tuner swap), remove the timing modules and set the max spark advance timing to about 22* or 23* to be on the safe side (a maximum of 25*). It will still be a 150hp not a 200hp, but these mods will really wake it up. I did this to my 2.0 liter 150, minus the tuner and stuffers, and gained a lot of midrange punch and about an additional 500 - 600rpm on top end.

[hooken203]

I thought about doing some of those things to this engine to increase HP but was told with the exhaust relief ports I would be a lot better off with a different block if I was going to start down that path. They said it’s a very dependable fishing motor at 150 hp and I should leave it at that. What about the oil pump would you replace it or run the original one?

[hooken203]

Removed double post.

[OnTRAK]

The 2.5 150 is definitely very reliable stock. Luvdmymerc gave some good advice on replacing the oil pump drive gear. At least check it, and replace it if it shows wear. For insurance, I'd replace it anyway. If the injectors haven't been serviced in a while (or ever), it would be a good idea to have them cleaned, flow tested and calibrated while the engine is apart. A bad injector going lean will take your engine out again quick. You might want to consider the fiber reeds. If a stainless reed chips or breaks, it too will take your engine out. Plus the fiber reeds will give you a better idle and a little better midrange response. Also, it is not a bad idea to remove the old timing module (trash it) and set the max advance timing to about 22*. If the timing module goes bad, it can over advance your timing and detonate a cylinder or cylinders. The engine & hp remains stock with these changes without hurting reliability. I learned all this stuff on here from Don and a lot of other smart people. That's why I made these changes to my engine.

[Have rod will travel]

Couldn't find the mag with the details, but I found some notes I had made. I would have needed an exhaust pipe tuner from a late 1980 2.4L 200. Also the carbs from a 200. The pipe tuner Merc no. is 41941c

[ChrisCarsonMarine]

The 150 block has much smaller ports than a 200.
The seal ring wear wont hurt anything as long as the same crank is used.
Seal ring wear would have no effect on cylinder compression.
The exhaust reliefs don't effect the performance noticeably,in a sport motor.
Modifing to a 200 would require porting and exhaust chest work,a different tuner and a 200 ECU.The electrics and fuel system are the same.
Our sport reeds and stuffers will improve idle and acceleration.We can mill your heads,but you will have to use fresh premium...ALL the time.
And,I would loose the 2nd rate oil mixer.

[Have rod will travel]

Thanks for the info guys. My engine is running ok, so I do not plan on doing anything to it.

[OnTRAK]

I apologize for my error on the 200 electronics & fuel system. I installed Chris' sport reeds in my engine about this time last year when I was rebuilding my carbs, and I did notice a nice improvement in idle and midrange acceleration just as he stated. Unfortunately, I found out about his stuffers shortly after I had installed his reeds, or I would have installed the stuffers too.

[EuropeanAM]

I will say that I like the "Stuffers" Chris is making, as they are completely removable if someone wanted to remove them. No "modifications" required.