Roos
08-08-2014, 01:50 AM
Hi,
I have a Mercury 2.4 200 hp from 1985 which have been giving me a few problems since I got it.
At first it overheated at idle and at WOT.
I have a transom mounted water pickup and when I finally got a larger sice nipple in the lower unit the cooling is much better.
Haven't been doind a lot of WOT runs with it since but it seems much better than it was before even if the temp gauge still creeps upward to 185-190 (though I have reason to believe it shows a little high).
I have then swapped to solid mounts and I have noticed a very small dribble / water leak from one of the mounts, just in case it might be related.
I have also cleaned out the carbs and installed new head-gaskets (mostly since I was looking for debris in cooling system).
As it is right now the motor is quite hard to get started and then idles really rough. It needs probably around 1200 rpm to stay running.
When idling like this the motor can go several minutes without reaching more than about 130 degrees temp. So it idles really cold and the thermostats won't open.
Could the low temp issue be caused by the small leak by the top motor mounts? Or should I suspect my poppet to be stuck open?
Could it be the cause for rough idle or be caused by rough idle?
When putting it in gear it is hard to get the motor not to stumble and die. Same thing goes for throttling up. Once on plane and above about 2500 rpm the engine seem to works just fine.
When pulling the heads I noticed that the engine seemed to have digested something sometime during its life span. In the top port cylinder there was a couple of small marks on the piston. Though compression is even throughout all cylinders. 125 psi +/- 5 psi.
Could there be a chipped reed and would that explain my issues?
Also when running the boat this year we have noticed an extreme fuel consumption.
The boat is a 17ft sports boat easily managing 70 mph and even though we are not really sure how many miles we traveled we used up around 20 gallons on what we think is 20 miles. Meaning 1 mpg. Could be 30 miles and 1.5 mpg but not anymore than that.
I did however find a small crack in one of the oil-mixing lines where it connected to one of the carbs (oil mixing has been removed) and it seemed to have been spraying or seeping a bit of fuel out that way. Thought I might mention it anyways since I guess it could be relevant to the rough idle if the engine is beeing flooded or something?
Thanks,
Mike
I have a Mercury 2.4 200 hp from 1985 which have been giving me a few problems since I got it.
At first it overheated at idle and at WOT.
I have a transom mounted water pickup and when I finally got a larger sice nipple in the lower unit the cooling is much better.
Haven't been doind a lot of WOT runs with it since but it seems much better than it was before even if the temp gauge still creeps upward to 185-190 (though I have reason to believe it shows a little high).
I have then swapped to solid mounts and I have noticed a very small dribble / water leak from one of the mounts, just in case it might be related.
I have also cleaned out the carbs and installed new head-gaskets (mostly since I was looking for debris in cooling system).
As it is right now the motor is quite hard to get started and then idles really rough. It needs probably around 1200 rpm to stay running.
When idling like this the motor can go several minutes without reaching more than about 130 degrees temp. So it idles really cold and the thermostats won't open.
Could the low temp issue be caused by the small leak by the top motor mounts? Or should I suspect my poppet to be stuck open?
Could it be the cause for rough idle or be caused by rough idle?
When putting it in gear it is hard to get the motor not to stumble and die. Same thing goes for throttling up. Once on plane and above about 2500 rpm the engine seem to works just fine.
When pulling the heads I noticed that the engine seemed to have digested something sometime during its life span. In the top port cylinder there was a couple of small marks on the piston. Though compression is even throughout all cylinders. 125 psi +/- 5 psi.
Could there be a chipped reed and would that explain my issues?
Also when running the boat this year we have noticed an extreme fuel consumption.
The boat is a 17ft sports boat easily managing 70 mph and even though we are not really sure how many miles we traveled we used up around 20 gallons on what we think is 20 miles. Meaning 1 mpg. Could be 30 miles and 1.5 mpg but not anymore than that.
I did however find a small crack in one of the oil-mixing lines where it connected to one of the carbs (oil mixing has been removed) and it seemed to have been spraying or seeping a bit of fuel out that way. Thought I might mention it anyways since I guess it could be relevant to the rough idle if the engine is beeing flooded or something?
Thanks,
Mike