1978 Evinrude 140 stalls when turned to right.

Evinrude 140 · #1 August 1st, 2005, 05:22 PM

I just bought a used boat with a 1978 Evinrude 140 (4 cylinder). In neutral at idle speed (in the water or with muffs), it sometimes slowly loses rpm after about 30 seconds and eventually cuts out. At higher rpm the engine is strong and smooth. I also found a strange phenomenon (try not to laugh): it seems to idle okay with the muffs when the motor is straight or turned to the left, but when the steering wheel is turned all the way to the right, it slowly stalls. I checked compression, 125 to 135 psi on all four cylinders. Replaced the entire fuel line(s) from tank to carbs, suspecting a restricted fuel supply or air leak, with no change. Also, I noticed the left side of the moter seems cooler to the touch than the right. Thermostat or plugged water jacket? Carb float? I bought a manual, but was hoping to stumble upon a quick fix instead of going through the whole engine right now. It is a short boating season in Maine. Many thanks!

00000dan · #2 August 2nd, 2005, 12:02 PM

i dont know what your problem is but i would like to know about having one side of the motor hot and the other not because i am having the same problem. 76 135hp.

fireman57 · #3 August 2nd, 2005, 04:35 PM

I would check my tstats on the cooling issue right away. No reason to fry this engine yet. Are you sure that your throttle cable is not getting in a bind when you turn to the right?

DHPMARINE · #4 August 2nd, 2005, 04:59 PM

Port side is always cooler on your engine,due to water flow thru it.A temp stick will tell you if either bank is too hot (over 163 degrees).

Sounds like motor stalls either way,just quicker turned to starboard.

Try pumping the primer ball to see if that eliminates the problem.If so,maybe time for a new fuel pump.

DHP

Evinrude 140 · #5 August 2nd, 2005, 05:48 PM

Thanks for the replies. I checked the throttle cable and electrical cables as I turned the motor, they are not the problem. I think I will change the thermostats, as suggested. I do not believe either side is over 163 degrees, but the port side is definitely much cooler. Maybe the port side thermostat is stuck open, which might explain both the different temperatures and the poor idle? I have a good feeling about this! I did try pumping the ball and choking as it started to stall, but neither helped, so I do not think it is a fuel supply problem anymore. Thanks again, will let you know how I make out.

jwyler · #6 August 2nd, 2005, 11:12 PM

This might be a long shot, but I had a similar problem... I was kinking/pinching the fuel supply tube against the transom when I turned one direction, which temporarily cut fuel supply and kept severing the tube. Took me a couple months to figure that one out...

Evinrude 140 · #7 August 3rd, 2005, 03:23 PM

Thanks jwyler, but I have been over and over the whole fuel supply chain from tank to carbs several times, making sure there is good flow and no restrictions. I have pretty much ruled that out. Thanks again.

OBJ · #8 August 3rd, 2005, 03:56 PM

Being a new engine to you, do you know the last time the carbs were serviced? A carb overhaul might be the fix. As for the heads....as DHP said, the port side runs cooler. Look on top of the engine just in front of the heads and you'll see a flat place. At idle, you should be able to put your fingers on that flat place for a few seconds before removing them.....that's on the starboard side. The port side may run cooler at idle.

One more thing to look at, check the spark with a timing light on both sides with the engine running. Make sure all cylinders are firing. If one side is not firing, it will be very cool to the touch.

Evinrude 140 · #9 August 3rd, 2005, 06:06 PM

The temperature on the flat spots is about as you describe on the starboard side, but port side is much cooler, barely warm. I just took the thermostats out, (which was a pain in the butt because of the big-*** exhaust cover above them!) and one of the thermostats had a small chunk of something wedged in it, keeping it from seating. Maybe that was the problem? On your suggestion about spark, wouldn't it run rough at higher RPM's too if the spark was not good? That is not the case, it runs great at anything above idle speed. Was I supposed to take the lower engine cover off to change the thermostats? I don't know how I'll get them back in without doing so. The manual doesn't really deal with those details. My hope of a quick fix is fading fast...

RandyJ · #10 August 3rd, 2005, 07:40 PM

Just a long shot...but, is there a possibility that the fuel pick up inside the tank is picking up something it isn't supposed to when you are turning right? Such as water or trash? You might check this by using a full tank of gas and proping up the Fuel line end of tank and having it toward the bow rather than the stern....or some kewl idea like that...maybe even having the pick up to the left rather than to the right...just an idea.

Evinrude 140 · #11 August 6th, 2005, 07:35 AM

It has a remote gas tank, and the stalling problem happens in the driveway with the muffs hooked up, so the gas pickup is not changing when the steering wheel is turned. Thanks for the suggestion. I am waiting on a new T-stat kit to arrive. I am hoping the stuck-open T-stat was the problem. I'd still like to know from anyone who has done this before whether I need to take the exhaust cover off or even worse, the lower motor cover, in order to get the thermostats back in. Thanks!

Evinrude 140 · #12 August 7th, 2005, 09:26 AM

Got the new thermostats in today. It definitely runs a little warmer on the port side of the engine, so that problem is resolved. However, it still stalls when turned to the right. I guess I will be doing a carb job this winter, I'm done screwing with it for now.

THANK YOU to all you experts that share your valuable knowledge for free, it's great to see such camraderie.

Mark