Is prolonged idling hard on motor?

i have an 77 Evinrude 85. Seems to be running ok.


Is it bad to idle in gear (or out of gear for that matter) for prolonged periods of time?

Here's the scenario. Trolling for kokanee on Lake Samish in WA. The battery for the minnkota dies before I'm ready to be done fishing. My 85 hp e'rude will do about 2.5 mph when idiling in gear, which is what I would consider the upper end of trolling speed.

Is it bad for the engine to be idle in gear for long stretches?

What about constantly shifting in and out of gear to attempt holding a slower speed than it will do at a steady idle? That sounds like alot of wear and tear to me, but what do you smart folks think?

I do have a 3 hp kicker that needs a couple things to be good, and than this problem should be in the past, but until than, what do you think?

Re: Is prolonged idling hard on motor?

Idling will not "hurt" your motor, there is much more of a risk of damage at WOT.However long periods of idle, will tend to build up carbon deposits. So if you run out to fish, troll out the battery, troll some more on the 85, and run back, I don't see a problem. You might need to do a sea foam cleaning on it, more often, and maybe the plugs foul out sooner, but thats about it. As for the shifting in and out of gear, it shouldn't cause problems either, unless you don't let the prop spin down, before shifting back into gear. Sounds like a pain in the arm to me, why not troll in reverse, the transom drag should slow you down more.

Re: Is prolonged idling hard on motor?

This is an odd ansewer but it works, tie about 15 foot of rope on a 5 gal bucket, tie it to the back of the boat and throw the bucket overboard, it will offer resistance and let you run the motor on a fast idle. Told you it was an odd ansewer.

Re: Is prolonged idling hard on motor?

I would not shift in and out of gear continuously as I think it does cause unnecessary wear and tare. I fish for kokanee at 3.5 mph for what it's worth and I'm not just saying that to save your gear case! You could also use a drift sock to slow down and I have heard of the bucket method although I haven't tried it. I heard you need a 3 inch hole in the bottom of the bucket. I do a lot of trolling and at the end of the day I always go wide open for 5 - 10 minutes to blow some carbon and oil out before pulling onto the trailer. Seems to work fine for me. Best of luck. Rick.

Re: Is prolonged idling hard on motor?

Agreed, don't shift it in and out of gear. The clutch dog and forward gear don't last forever, even under normal use.

Re: Is prolonged idling hard on motor?

i troll for hours upon hours for kings and ive found that regapping the plugs wider helps a lot.for example if it calls for .030 go to .040.it works fine and ive never had a running issue.yes the bucket method is the poor mans trolling plate and is or was very popular around here,ive seen it on 50,000 dollar boats

Re: Is prolonged idling hard on motor?

drill holes in bucket, agree old trick for trolling is to open the the plug gap to .035 or .040. creates less plug fouling. decarb the motor more often.

Re: Is prolonged idling hard on motor?

Use good quality synthetic oil, keep the thermostat working properly, and use the correct spark plugs if you troll a lot, and you will have less carbon build-up.

Try to set your idle at the recommended 650 RPM in gear, under load, engine warmed up and unrestrained.

Carbon Guard or Ring Free or similar fuel additive will help. Be sure to perform the recommended annual de-carbon treatment.

Re: Is prolonged idling hard on motor?

Daviet said:

This is an odd ansewer but it works, tie about 15 foot of rope on a 5 gal bucket, tie it to the back of the boat and throw the bucket overboard, it will offer resistance and let you run the motor on a fast idle. Told you it was an odd ansewer.

Click to expand...

I think you just described what's called a "sea anchor." It gives resistance against drifting, but not actually anchoring to a standstill.

I have trolled almost 4 or more hours without a break, other than shifting out of gear to haul in a big fish (hog sea trout). Fortunately, I have a high-speed run back up river to burn out carbon build-up that may have occurred. I usually change plugs once a year - need it or not.

What's the process to "seafoam" a 2-cycle engine?

Re: Is prolonged idling hard on motor?

wellsc1 said:

What's the process to "seafoam" a 2-cycle engine?

Click to expand...

The newer motors have schrader valves for injecting the aerosol treatments. For older motors like this one, follow the instructions by Capt.Dunkelberger in the Engine FAQ forum: http://forums.iboats.com/showthread.php?t=158076

Re: Is prolonged idling hard on motor?

We have a boat at a club that is very heavily used--almost commercial use in the summer. When we wore out a clutch dog, the mechanic looked at the parts and said, "looks like a lot of flounder fishing" because that's when you are constantly shifting, forward and reverse, all day long.

Any use will wear on a motor. But they are made to be used and that's why you have it. But here are things that will help:
After (or during) long periods of slow running, go take a fast ride or at least give a quick rev in neutral--not too high, though.
Do not shift from F to R, or R to F, without pausing at neutral and letting the prop stop spinning.
Along these lines, don't routinely use R for a brake; get better at docking speed.

Shift HARD into or out of gear. Some people think they are saving the parts by easing into gear--that grinding noise is not your friend.

After impressing our club members with these (should be obvious) techniques, and restricting drivers to those with experience, we have made the lower unit last much longer.