115 merc problems - Maxum Boat Owners Club

bnsf215 · 08-11-2008, 04:49 AM

I have an 1800 xr with a 95' 115 merc elpto. Runs fine, starts fine, surprising out of the hole, but when coming off the throttle it sounds like there is some knocking. This occurs only when decelerating. Any ideas? I am hoping its not getting wore out but for its age probably so.

tglee · 08-11-2008, 06:53 PM

Has this been happening for a while or did it just recently start? Maybe you got some bad gas or the gas has been sitting in there a long time. you can try adding some gas stabilizer. You may also see if using a higher octane helps. Then there is always this to think about. A little-known phenomenon called deceleration knock. Lacking proper carburetor jetting, the outboard will audibly “knock” (similar to a car “pinging”) as the throttle is released, typically when backing off after a high-speed run. The solution is slightly richer high-speed jetting.

It's great to have another 2-stroker on the boards. Please post some pictures for us.

bnsf215 · 08-11-2008, 10:58 PM

It does occur as you back down after running hard for a while. I have only owned the boat for a few monthes. I asked a friend too and he thought it may be something in the lower unit winding down. Thanks for the input. I will work on the pics. It is the same as yours, great looking boat. Very happy with the performance under load and when just out for a cruise. I live in North Dakota but do all my boating in the land of ten thousand lakes. I have had it on some bigger lakes and it really handles well in rough water. Hopefully its nothing major. Have you had your oil reservoir replaced? The dealer said it was common with this model when trimmed up to trailer the tank would leak a little. I have just been keeping it low enough so its not a problem while it is on order.

tglee · 08-12-2008, 05:38 AM

I doubt it is related to the lower unit. however, if you haven't changed the oil in the lower unit you probably should. there's no telling how long it has been in there. Remember to replace the three small gaskets around the screws also.

I still have the original oil tank. It does seem to leak a little when the motor is locked in the uppermost position. Another common problem is with the low oil level sensor. There is a magnet attached to a float, when the magnet gets close to the bottom of the tank it sounds the alarm. The problem is that many times the magnet falls off the float and the alarm constantly sounds.

bnsf215 · 08-12-2008, 05:06 PM

Thats a good idea too, you never know when it was done last. That oil tank is $100 if you wanted to get rid of that problem. Using the transom saver doesn't make it go up high enough to leak so it not really a big deal trailering either.

tglee · 08-12-2008, 06:18 PM

Do you have the original Escort trailer? I purchased a transom saver but I can't figure out a good way to mount the bracket. So I really need to see some pictures of that.

See my post here:
http://www.maxumownersclub.com/forum...hp?p=3844#3844