1981 merc 200 performance

[THEFERMANATOR]

Originally Posted by jamesbalog

the johnson was an 88 so it was prop rated

thanks for the explanation

Yep, you swapped from a 175 to a 175, so performance will be about the same. But like you found out, the 2.4L MERCURY is ALOT better on fuel than the old OMC crossflow was. Reprop to a stainless prop, and let it turn up to at least 5300 and it should do a bit better performance wise. And take care of that 2.4L MERC as it is a good engine.

[RidgeRunner]

Most folks don't know it but the old 2.4L 200's and 175's were chrome bore motors.. The chrome isn't the same chrome as what is on your bumper of your pick-up truck. This chrome is a chemical process essentially making the bore very hard. One thing that the chrome bore 200 did not like was being lugged around. Lugging the motor, ie. tuning the setup so that the motor is not in the recommended WOT rpm range, generates additional heat and could lead to pre-detonation. Translation- Certain death to an old carbed 2-stroke.. They didn't like heat because heat could cause the chrome to start to give up and flake off the bore.
Keep the carbs clean too, it should last a while if you follow the rules. LOL! Performance isn't bad for such a load, your using it to its potential..

[draglink]

you might need to re-prop. I have about the same motor. '80s 2.4 200. I turn it 6100-6300 WOT depending on the chop. Motor wants to turn more! I bump 50mph, fastest I have seen on GPS is 53

[RidgeRunner]

I like 5800 RPM. Apparently so does Mercury because at least two of my motors have a 5800 limiter. Draglink- Funny you should say that the motor wants to turn more rpm, they really are a lot happier winging it up high, it is leverage and gearing.

[THEFERMANATOR]

Originally Posted by RidgeRunner

I like 5800 RPM. Apparently so does Mercury because at least two of my motors have a 5800 limiter. Draglink- Funny you should say that the motor wants to turn more rpm, they really are a lot happier winging it up high, it is leverage and gearing.

It's the porting. The older 2.4L MERCS porting doesn't like low RPM's as I understand it. The porting in the engine wants RPM's to increase the air speed through the engine. Most loopers don't like to be lugged, it's just how loop charged induction works. Now cross flows on the other hand pull great down low. I know even my 2.5L I had was MUCH happier when I jacked the jack plate up and turned it up over 5600 than it was with the prop buried turning 5300. It just felt better.

[draglink]

My Merc guy(good friend) who built it says turn it , turn it, turn it! I always come back to him with "of course YOU are telling me to turn it, you want to build it again!" HAHA!!

He is a racer and has a shop FULL of boats that he races every Saturday. He has a sweet 2.5 race motor sitting on a stand I would love to hang on the v!

He built mine 5 years ago, she turns like that every summer weekend and loves it! I wanted to put some cup in the prop, maybe grab a little more top end, but I haven't messed with it

[bigshrimpin]

1981 V200 will be a vertical reed non fingerported 2.4L

It's a decent engine . . . performance is similar to the mid 80's 175. The mid 80's vertical reed 2.4L fingerport 175 will turn about 200 - 300rpm faster than the non fingerported v200. I ran both setups on the same boat and that was my experience.
You can gain power from swapping the front 1/2 to a horizontal 2.4L reed, but you'll lose some of the kickass fuel economy. I run a 1987 2.4L vertical reed 175 powerhead (on top of a 2001 200 midsection) pushing my 23 seacraft (which is a much heavier hull). Get the boat setup right (engine height . . . cavitation plate about 1.5" above the bottom of the boat . . . then play with different props). Setup right . . . you should see some improvement in fuel economy and speed from where you are now.

https://www.youtube.com/watch?v=jg7cdw1vE

[garbubba]

I've run a 1994 2.5 liter merc 200 for years. I use a stainless 19 pitch prop, WOT is around 6k & top speed about 45mph by gps. I've switched props in the past, & this one seems best.

[bgreene]

Look forward to your #'s after you switch props........

Also, make sure it's rigged high enough on the transom.
Many boats are run with motors lower than actually needed.

[reelapeelin]

Originally Posted by RidgeRunner

Most folks don't know it but the old 2.4L 200's and 175's were chrome bore motors.. The chrome isn't the same chrome as what is on your bumper of your pick-up truck. This chrome is a chemical process essentially making the bore very hard. One thing that the chrome bore 200 did not like was being lugged around. Lugging the motor, ie. tuning the setup so that the motor is not in the recommended WOT rpm range, generates additional heat and could lead to pre-detonation. Translation- Certain death to an old carbed 2-stroke.. They didn't like heat because heat could cause the chrome to start to give up and flake off the bore.
Keep the carbs clean too, it should last a while if you follow the rules. LOL! Performance isn't bad for such a load, your using it to its potential..

Vic...ya mighta just diagnosed another 2.4 failure we know about...I never felt I was gettin' it all...