The Infamous L-Drive Overheating!! - Maxum Boat Owners Club

MaxDizz · 05-24-2014, 11:26 PM

New guy here. So I have a 1990 Maxum 120 L-Drive. Boat does fine on the trailer. Boat does fine at low rpm, 1000-2500, putting around. It has a hard time getting up to speed but it will eventually make it....but it overheats after a few mins of running over 3000 rpms. Would this possible be an impeller issue? I like the boat but I'm getting stranded every time I go out!!

mmwjr · 05-25-2014, 01:43 AM

Max welcome aboard.

My first thought is the impeller but you mentioned power power.

Is the engine showing signs of over heating then loss of power or the other way around?
The L drive uses a Force outboard power head and may be nearing end of life which results in excessive heat.

Try replacing the impeller and see what happens. Unfortunately there is no easy way to rep owner the L drive.

Post back with the results

MaxDizz · 05-25-2014, 11:48 AM

Thanks Mike. Im new to boating which also makes me new to this rare motor. After reading and reading and reading my first step was the impeller. Since that is an item that is a probable cause and is inexpensive I will start there. Ive read that some suggest as previnative maintenance replacing this once a season or two?? ANd Ive watched a video or 2 on the replacement but how hard is it really? I plan on doing this myself. And there is no power loss at overheating. It just takes a little bit to get to speed. Is that normal for a 120 on a 21ft cuddy??

mmwjr · 05-25-2014, 12:07 PM

I don't know the exact proceedure to replace the impeller for this set up but for merc Alphas is requires you to drain the gear lube but on O/Bs you don't have to. Since this is more like an O/B I am thinking you just need to drop the lower unit to gain access to the water pump housing where the impeller is located.

If you have any mechanical experience it won't be that bad.

How many people are on board and how much gear typically. The more weight the slower the time to plane. Try shifting some weight forward. Does the boat have trim tabs?

MaxDizz · 05-26-2014, 11:57 AM

Ok. So getting to the impeller was very easy save the lower unit being stubborn in coming off. As long as it goes back on with the same effort I would suggest no one with this type of motor ever pay to have this done. I do not have the parts yet, I wanted to see how bad it was first. The impeller looks ok...now I dont know if most motors are set up the same way but the impeller slides inside of a metal sleeve and it fits over the drive shaft. Then a plastic housing fits over that. The metal sleeve has a notch in it that catches on the housing to keep the sleeve from turning....I assume only the impeller is suppose to turn during function. With all that nonsense that you probably already knew, the plastics housing has a crack in it. Its small but big enough that I can see daylight through it. The obvious is that I need to replace but could this be a reason for the overheating at high rpms?

mmwjr · 05-26-2014, 12:56 PM

If the housing is cracked then it will leak under pressure created by the impeller so this results in less water flow to the engine so I can see this a being the cause for overheating.

Most engines have a way of telling if the pump is working in the form a small water jet that shoots out water in steady stream, anything like that on this set up?

MaxDizz · 05-26-2014, 01:11 PM

Hopefully that will solve my problem. I can get the rebuilt kit for about 90 bucks. As for the pisser, which is what I think you're asking about, its different. There are 2 holes on either side of the LU. Right above the water intake (where I put the muffs on). On land they always have a decent stream, in water I can not see them. Underneath there is a large, 3.5" dia, hose that feeds water up to the engine. The way it circulates it comes back out a 1' hose directly beside the large intake hose. At first I thought something was wrong until I climbed under there and saw what was going on. So i think the answer to your question is...on land, in neutral, everything seems to run as it should, even when I run the rpms up.

mmwjr · 05-26-2014, 02:51 PM

yep that's what i was refering to. all you can do is replace the pump and see what happens.

MaxDizz · 05-26-2014, 03:28 PM

Thanks For the help. I will order parts and install them this week. I'll let ya know how it goes this weekend!!

Joshua · 05-09-2020, 07:03 PM

I am having an issue trying to find engine coils deos any one know where I can get them and not have to trade my kids in on them thanks for the help and yes I am a new boat owner. Just got a good deal on this guy

donald · 05-09-2020, 07:59 PM

Best to start a new post as to your problem as this is a 6 year old post.
Post your signature with boat model, engine and drive info so we can help you.
Also welcome.
Don

mmwjr · 05-09-2020, 08:47 PM

Quote:

Originally Posted by Joshua

I am having an issue trying to find engine coils deos any one know where I can get them and not have to trade my kids in on them thanks for the help and yes I am a new boat owner. Just got a good deal on this guy

As Don said best to start a new thread as this only is old, about overheating and L drive. New thread should be what engine and looking for coil packs.