cooling issues

[tomoad]

on a 1988 2.4 200 fishing motor, will 1 pc heads cool better than the two pc heads

[sosmerc]

With proper setup and service, there is no reason you should be having cooling issues with a stock 2.4....one piece or 2 piece.
If it's a salt water motor, it may be time to take the heads apart and bead blast all the surfaces clean. If you want to run a little cooler, substitute 120 degree thermostats for the 143's. Service the poppet valve assembly...consider cutting one coil out of the poppet valve spring....it will then open a little sooner and give you better block cooling at between 1800 and 2500 rpm. And naturally, always start your season with a new water pump impeller and pump gaskets.
Highly recommend a water pressure guage, and a temp guage, and a tach.
If you still have cooling issues, be sure to post some basic data such as engine serial number, water pressure at various rpm's and any mods that have been done to the motor.
Good Luck!

[us1]

Yes they will.

[tomoad]

this is a fresh water motor only, replaced (everything) in the popit valve assembly, new thermostats, new water pump,(i have a sportmaster lu) have always had a tach, temp gauge, and water psi gauge, i have plenty of water psi, 23 lbs sometimes more, (motor is setting low on the jackplate). my temp gauge does not say the temp, it just has cold and hot, anyway it has always atleast for the last year anyway ran on the hot side where the red mark starts, just as soon as i come to a idle it cools back down, i'm starting to believe it's the nature of these 2.4's. i guess if it was to hot the warning horn would go off and would have burnt up by now, just thought maybe the 1 pc heads would cool better, i've tried the quarters that i seen trex mention one time in a post with different holesizes, 1/4 3/8 and so on but i like the t-stats better, so it would slow the water down and cool it better like it was designed to do, my holes may of been too big it just seem like the water was going too fast threw the motor to cool it. and i have heard one pc heads cool better and thought about giving it a try. thanks for your answers

[T-REX]

1 piece heads do cool better than 2 piece, but slowing down water flow don't cool an OB...It cools with more water flow...Unlike a car motor, if the flow ov water iz too fast, it won't cool, because it don't stay in the radiator long enuff to cool...OB's have a bigger problem building heet with open water flow, sumtimes a pumped up 2.4 haz a cooling issue because ov the lack ov cooling holes drilled in the block, the 2.5's have the extra holes...Thermostats build heet quick, because they only open at a certian temp...once open, it flows the same az a 3/8th open hole, but if the temp drops below a certian temp, the thermostats will close...I run thermostats in the winter on my stock motors, but use the quarters wit 1/8" holes for summer, and even bigger if water temp git's hotter...REX

[us1]

They do run hot in the stock state but that’s what they should do. The problem is you really need a gauge that has numbers on it and a sensor that is in the water jacket. That way you will really know what’s going on in there.

[tomoad]

i agree, thanks for you all's help

[tomoad]

does mercury make one ith the numbers on it

[AnthonySS]

It Sounds like I have similar problems with my 84 2.4 200.

I am on a very weedy lake so I do not run t-stats. I belive my restrictor washers have 1/4" hole (Standard merc washers).

Mine will actually come up as hot as the Horn at times...mine just does not seem to want to make any pressure either. Lots of water coming out of the tell tale...but very little pressure ( not much more then about 6psi) and engine will get hot before I can even get it to run WOT.

I think part of my problem is a 2 hole CLE on Weedy lake...I had the same problem years ago with the same case. Most times after an outing I will inspect the inspection plate area and find some weed debris in there.

I need to try a differnt Gearcase...aslo is there any service that should be done to the poppet valve?

Interested in your input guys and THANKS

[tomoad]

got me an new gauge, one with numbers on it, what temp should it be around 190, 180 ?????

[pyro]

My 2.4 200 never goes over 160 at any speed (except when idling with a bad impeller :D )

[hsbob]

tomoad


sound like you poppet is starting to go south. the 23psi and higher sound to high. my 2.4 and 2.5 would max out at 15 to 18, until the poppet start acting up.

[kingsbiship]

I have to side with T-Rex! The blocks on the 2.4s are different!
Some have a group of 3 holes and some have 2! I make all the blocks
have 3 holes... 12 altogether! I've even went as far as to drill holes
in #1 & #2 cyl. where the wall is very THIN! Then modify the gasket &
cover plate accordingly! I also add diverters... but leave space at top
& bottom for a little flow (don't want stagnent water cooking)

[tomoad]

went to the lake yesterday, 81 degree water temp, according to the gauge cruising around 3500 to 4000 rpms 200 degrees, wot around 220 degrees, when i come back down to idle it cools off to 160/170 degrees.