In need of Basic Operation instructions for my '73 Merc 1150

[AntelopeWI]

Hello everyone,

So I feel a bit silly asking this, but I am new to boat motors, and I need some real basic operation guidlines. I have gotten my engine running, and am excited to try it out. Just haven't operated a boat engine by myself before. Just been going off what I observed from my Dad and Uncle with their boats when I was a kid many years ago.

To start it, I pulled the warm-up lever all the way up and depressed the choke button.
How long should I leave the warm-up lever up?
I suppose until it warms up. Seems to rev high with it up all the way up. I have been easing it down to the point where it starts to bog down a bit. The other day I ran it a bit longer, and then pushed the warm-up lever all the way down. The engine didn't die. Seemed to settle into a nice idle. I'm assuming I warmed it up enough.
Is that the right way to use the lever? Do I have to wait until I push it down before using the throttle/shifter lever? Do you just use the lever if the engine is cold?

When I put it in reverse, do I pull the throttle all the way back? Does the engine not rev as high in reverse? Or do you only pull it back a bit?

Any basic do's/don'ts I should know about? Really any info would be appreciated and help me feel more confident. I am just nervous about doing something wrong and damaging the engine after I have put all this time and energy into fixing it.

thanks,
john

 

[emckelvy]

Re: In need of Basic Operation instructions for my '73 Merc 1150

Fast idle lever is used pretty much as you described. Hold the choke button down until the motor starts. Use as much fast idle as you need to keep it running stably until it warms up. If the motor tends to die when you release the choke button, hold it down again. You'll know when it doesn't want anymore 'cause it'll slow down instead of speed up when you choke it. Note that the choke button activates an electric solenoid which pulls on a plunger to move the choke linkage. The choke shutters are closed only as long as you hold down the button.

One thing you'll want to add to your startup routine is to pump the bulb up hard and then another squeeze for good measure. These old Beasts like lots of fuel for cold starts. Any time I thought I had flooded my '71 1350, turned out it just wanted more fuel!

BTW 1350's (Red Stripers) were only made in '70 and '71, you've got a Classic indeed!

On the shifting, only use as much throttle as you need for Reverse. As you surmised, throttle travel is limited but you normally don't need a lot unless you're trying to halt forward motion.

When you shift be sure to use a sharp motion with the wrist, don't 'ease' it in gear (this wears out the shift clutch and the 'cogs' on the gears).

A few other tips, it would probably be a good idea to rebuild the fuel pumps. Alcohol fuel tears up the old diaphragms and this inexpensive & easy maintenance will save you a lot of grief.

Pick up some Seafoam or the Mercury/Yamaha/OMC carbon cleaning product and do a decarbonization treatment as per this FAQ:

http://forums.iboats.com/showthread.php?t=158076

Tune up your motor with a nice new set of Champion L76V plugs, or NGK BUHW as an alternative. Drop the distributor cap (you don't need to disconnect the wires) and clean it out. The cap is held in place with a stainless clamping band and one screw. Note the orientation of the clamping band to make sure it goes back the same way.

Likely the cap will be be full of carbon dust and other corrosion products. Carb cleaner will flush the stuff out nicely. Just let it air out before installing! Check the spring-loaded carbon contact in the center of the cap, it should be free to move. If not, pull it out along with the spring and clean/reinstall.

Caution on the plug wires, they screw into the cap so you'll just ruin them if you pull them straight out. The rotor does not come off the shaft, so don't try! It's a very very expensive part to replace if broken!

Check your gear oil, the drain plug's at the bottom of the L/U and the vent/fill level plug is up by the anti-ventilation plate. Right next to a flushing screw, don't get them mixed up! The vent plug is located aft of the flushing screw.

Pick up a quart of Hi-Vis marine-grade gear oil and a hand pump (should cost less than $10 for both, check your local Wal-Mart marine section near Automotive or Sporting Goods). Pop the drain plug first, then the vent. After draining, screw the pump into the drain hole and fill until oil comes out the vent. Reinstall vent plug, remove oil source, install drain plug, that's it!

For fine-tuning the motor, it won't like to run a lean idle mix. You'll have to settle for a slightly "lumpy" idle to keep it from hard-starting and bogging on the hole shot.

Each carb has an idle mixture screw on the right side. Warm the motor, in the water, and idle in gear. Adjust each screw for highest, best idle. Once all (3) carbs are adjusted, turn each idle mixture screw approx. 1/4 turn CCW (rich). Check the hole shot, if it bogs, try another 1/8 turn to the rich side and check hole shot again. If one more adjustment doesn't help, there are other issues you'll need to address (carb service, primer bulb, fuel hoses, tank).

If you need to readjust your idle speed after setting the idle mix, use the Idle Stop screw on the distributor front bracket, to make an adjustment. This is the most outboard screw of the (3) on that bracket. The inboard screws are for Throttle Stop and Spark Advance (maximum spark advance setting) and you don't want to mess with those until you're ready.

Use Stabil Marine fuel stabilizer or other marine stabilizer such as Starbrite. Ethanol blends are tough on these old fuel systems. And the anti-corrosion additives in the stabilizer will help keep the lousy fuel from corroding the carbs.

BTW mix fuel/oil at a 50:1 ratio. Use a Name Brand fuel (I like Chevron myself) and major mfr's TCW-3 oil or a quality aftermarket brand. Penzoil makes a pretty good 2-stroke oil and your 1350 would like the Penz Synthetic. Your local Wal-Mart may carry that as well.

Be sure to get a good service manual for your motor. Until you have that, use this forum's Search feature for tons of tuning and service Tips for your Tower of Power.

The repair FAQ has a lot of good info to check out as well.

This is of particular importance for an Inline (Link and Synch procedure):

http://forums.iboats.com/showthread.php?t=168855

And, last but certainly not least, Change the Impeller!!!! The very inexpensive part can really ruin your day when an old impeller lunches itself. Not to mention a $1500-$2000 repair bill !

You'll find some parts for your motor here at the iBoats store. These sites sell parts and also offer good diagrams which will really help in figuring out what you've got and what you need:

www.boats.net
www.crowleymarine.com
www.mercruiserparts.com

The 1350 is right at the top of my list of Favorite Motors I have Owned. Many times I've regretted selling it. Guess I'll just have to build another!

HTH & enjoy yours................ed

 

[AntelopeWI]

Re: In need of Basic Operation instructions for my '73 Merc 1150

Thanks Ed for all the info. That's great.

I have a 1150, not a 1350, but I think they are similar in operation.

Here is what I have done so far. ..
Overhauled the fuel pumps. Replaced a leaking internal fuel line and the feed line to the gas tank.
Put a new (used) distributer on it, as that seemed to be the root of the problem with it. The little pickup arm inside the cap on the bottom of the trigger had broken off and the previous owner JB Welded it back on. Also put new (used) spark plug cables on as the ones on there looked like they had been attacked by mice or something.
Checked compression. All between 115 and 123.
Had to remove the flywheel to switch the distributer assembly.
I drained the lower unit. Found some water. Replaced the water pump base with a new one with new seals. Replaced the water pump impeller, upper housing, baseplate, and gaskets. She pumps real good now.
I put Quicksilver lower unit gear oil in and put the screw plugs in with new gaskets.
As for gas... I got 91 octane as it was the only one around me without ethanol in it. Hope that is ok. I put some Marine Stabil in it. I used Mercury Quicksilver 2-stroke outboard oil in it at 50:1.

Think I'll do the Seafoam think you mentioned. Thanks that was an imformative post.
The idle adjustment info is very helpful. I was wondering about that.
I would like to overhaul the carbs, but seems like it would be a pain to get them off. I will though, just hoping to get some use out of it this season yet as I live in the UP and have a narrow window.

THis fourm is great and has been a great resource. I have a Seloc manual for it, but I find this fourm very helpful.

Another issue is I need to adjust the shift cable. Seems to be a hair off.
I wrote a post about it right before this one.
http://forums.iboats.com/showthread.php?t=421364


Again, a world of thanks for taking the time to help me out. I really appreciate it.

john

 

[emckelvy]

Re: In need of Basic Operation instructions for my '73 Merc 1150

OOps, guess I better check my glasses! :0

Oh, Well, the stuff still generally applies, your 1150 has a slightly different block with upgraded exhaust tuner but the pistons and crank are the same as the older motor.

Sounds like you're well on your way to getting your Inline purring! BTW the carbs are not a lot of fun to get off the motor, but unless they're really messed up you can do a lot of maintenance on them without removing from the motor.

The filter tops come off, this lets you get at the float bowl and replace floats, check needles/seats, spray with carb cleaner, blow out, etc. Pull the idle adjustment screws and you can blow carb cleaner and air thru. Pull the brass main jet covers on the upper 2 carbs and you can flush cleaner and blow air out those holes. The bottom carb's main jet cover is a bit harder to get at but it's do-able.

The "carb packing kit" would have all the little gaskets etc you'd need to do this quickie carb servicing. You'll need to get one packing kit for each carb.

For more extensive carb work you're gonna have to bite the bullet & pull them off the motor.

I'd recommend replacing the floats if they're the old formed/foamed plastic type. Ethanol fuel tend to chew these up. The newer floats are supposed to be alcohol-resistant. Float needles/seats need to be replaced as a set and be sure to check the height/drop at the float lever after replacement.

Speaking of carbs, it'd be best to disable the 'back-drag' feature if you have it. A little black vacuum hose goes from the carb throat to the top of the float chamber. Airflow at mid-speed and higher rpm draws a vacuum on the float chamber. This causes the mixture to lean out, for fuel economy. The float chamber is vented, and there is a 'vent jet' screwed into the cover. The size of the vent jet determines how much vacuum is pulled on the float chamber; a larger jet (or no jet at all) would develop less vacuum than a smaller-sized orifice.

Anyway, that's how it works, Bad News is it was an idea that didn't work out so great for Inlines, which don't like to be leaned out at all! They tend to burn pistons when run lean, especially on today's Wonderful fuels! ;(

To disable this function, you need to block off each back-drag hose. Some folks stuff a BB in the hose, this plugs it up real good. Then just hook it back up and this keeps debris out of the float bowl. It's also recommended to remove the vent jets, if you can't get them out it'll probably be OK since there will no longer be any vacuum being pulled on the float chamber.

Your Merc might use a tad more fuel at higher speeds but then no one said these were Gas Mizers! Your pistons will thank you, though.

Anyway, like Forrest Gump, that's all I've got to say about that! Have Fun..........ed