Factory Starting Procedure For 1991 120 HP L-Drive - Maxum Boat Owners Club

BoaterBob · 06-04-2024, 08:13 AM

Ok guys, newbie good to be aboard. I have a question that may sound extremely stupid! I was taught by my late grandfather, "The only stupid question is the one that was never asked."
So here we go, I have a 1991 US Marine (Force) 120 HP 2-Cycle Maxum 2100 LDC (L-Drive). I would like the factory starting procedure for throttle setting, how to use the carb enrich ignition switch, the US Marine (Pull Out For Neutral Throttle Lever) and whether to pump the throttle 5 or 6 times forward back to the the first forward neutral indent. I have read so many starting procedures, I'm spinning, the motor not so much! It cranks until the battery dies, have spark until then. All I want is the factory starting procedure. I had this thing running perfect last season, only to get an overheat alarm after 3 minutes, the manifold was still cool enough I could lay my hand on it, so I don't think any damage was done. Replaced the old impeller (was like someone had super glued it to the stainless cup.) The upper plastic-Bakelite water pump housing was full of cracks, all since repaired and pressure tested per the factory shop manual. When it overheated last season, there was no thermostat or associated parts in it either, no rust issues present. Ran water through the block with the garden hose, complete flow out the power head with the leg removed. Tested the water pump with a rigged motor to turn the warter pump, working as should. Shift cable and rod adjusted per manual instructions, working as required. Thermostat is now in place with all accompaning parts. The service manual also has in bold black letters, "DO NOT INSTALL FUEL PRIMER BALL!" I think this is actually my no start issue now. The stator was replaced last season as well, 2 fields were fried in the origininal. Was lucky enough to find A NOS stator in the original box! Fired right up after that fix last season. When I rebuilt the carbs last season I primed the bowls with fuel as advised in the manual. I think the fuel in the bowls has evaporated and the diaphram flapper fuel pump (Completely rebuilt) isn't strong enough to pump fuel to the empty carbs. I'm gonna chance it against the manual warning, and add the primer ball where there had been an inline fuel filter. Any leads on the correct starting procedure would be greatly appreciated. I know this is a long one, just wanted to include as much info as I could, so I was'nt bombed with questions. Thanks crew!

mmwjr · 06-04-2024, 01:25 PM

Welcome aboard!

Not many L drivers still around as Maxum and Bayliner only produced these boats for a couple of years. As you probably are aware this is basically an outboard incorporated into the hull like a I/O. I’m not aware of a starting procedure but it should be the same as most outboards. Maybe someone here can provide the details else you may want to try a forum more centric to outboards.

BoaterBob · 06-07-2024, 02:59 AM

Hi Mike
I know from the brochure info for 1990 the L-Drive was an outboard power head placed in the engine bay just as the motor part of an inboard would be. They made a hybrid outdrive that had a straight drive shaft the exited the engine bay straight down through the hull into the top of the outer tilt up/down drive leg. The concept was ingenious. Would have eliminated lots of rubber if they would have crossed over to 4 cycle. Copy of the brochure attatched.
Bob

mmwjr · 06-07-2024, 04:53 PM

Thanks Bob, yes I remember when they came out and was impressed with the design. Force outboards were a bottom end market motor and the line was discontinued. This leaves no simple retrofit based on its design and the hull design. Hopefully you get several more years out of yours.

porthouse1978 · 08-23-2024, 08:01 PM

So I have the same issues you are having. I can get the boat started at the house after a couple chances of starting it. Then I get to the lake starts right up as soon as I shut it off and try to start it back up after awhile it hard to start. How my Dad and I have been starting the boat it a couple clicks of the choke with the throttle in the starting position with one hand on the throttle and one hand on the key just in case the boat gets away from you. Which means fires up and redlines. I have since put a new fuel pump on it all new fuel lines rebuilt the carbs and still had issues starting. The guy I took it to to have him adjust the carbs and idle says I was starting it wrong. He was saying to push in on the choke with the throttle all the way open and again one hand on the throttle and one hand on the key. So I got it to start at his place as soon as I got home it wouldn't start. It would acting like it was trying to but would struggle. I gave it two clicks and half idle and it fired right up. These kind of engines are cold bloody but once they are warmed up they run forever. it just the starting issue. I am going out in it for last summer vacation hope everything works on it and we can finish the season strong and having fun until next year. Can't complain I mean the boat is 34 years old.

Thank you
Patrick

shrew · 10-09-2024, 06:59 PM

Two issues I suspect effect older, carb'd boats.

1) The fuel has to be primed all the way to the carb and the fuel bowls full.

2) As these carbs get older, they really rely on choke and some advance of the throttle while starting. To me this seems like reduced flow in the pilot (idle) jet requiring the main jet be opened and the air reduced to get the proper balance for initial ignition.
I suspect this is caused by the gumming of the jets over time. Even cleaning isn't the same as replacing the jets during a full rebuild.