Where to start

Texas Heat

Cadet
Joined
Jul 10, 2002
Messages
27
Took the boat out Monday (15” Doggett / 1972 – 65 hrs Evin- hydro / electric )<br />She would not start. Second time this has happened . I ran on muffs Saturday fine. I do not know if all the bouncing around driving to the lake is jarring something or what. It seems to me that the motor is flooding out and fouling the plugs. When I got back home, I tried to turn her over, after a couple of turns of the key, she fired up! This is getting old! I want to be able to actually drive the boat not hear it run in the driveway! Duck season is fast approaching and I need to have confidence in my rig to get me to and from the boat ramp! Should I start with a carp rebuild or should I start with something else. I have my outboard manual but there is nothing in it as far as trouble shooting goes. Post up OMC gurus!
 

ob

Admiral
Joined
Aug 16, 2002
Messages
6,992
Re: Where to start

Carbs sounds like a good place to start .Orifices in carbs are frequently tarnished and gummed with old fuel/oil deposits when motors sit idle between uses
 

kev_alaska

Petty Officer 2nd Class
Joined
Jun 6, 2002
Messages
169
Re: Where to start

Do a search on this site for "backpressure, starting" <br /><br />Running on muffs versus in the water has been discussed by smarter guys than me...<br /><br />Kev_alask***
 

Texas Heat

Cadet
Joined
Jul 10, 2002
Messages
27
Re: Where to start

Looks like I will be playing the guessing game that is engine trouble shooting! I am not sure if it is a back presure issue, I am real green when it comes to boats! This is my first one. I think I am not doing something right @ the lake during my starting procedure. When I start the motor @ home, the motor is up via a transom saver bracket. Say maybe 30 degress. When the boat is @ home I leave the fuel tank cap loose. When @ lake I will back the trailer in lake get out and make sure gas tank lid is closed tight, pump the hose a few times, I then go around to the back and bring the motor down to make sure the prop is clear of the bottom (Hydo /electric prop will spin a few times while starting) I will jump in the boat and turn the key while holding the choke switch. I have had the boat out three times, only once was I able to get it to start. When it does run it runs very well for a 30 year old motor. It just seems that the motor is flooding out on me. Unlike a car motor, you can't "Floor It" to get it to start if you flood the motor.
 

Backlash

Chief Petty Officer
Joined
May 16, 2001
Messages
586
Re: Where to start

Hey Tex,<br />Sure sounds like a fuel delivery issue to me. Check everything from the tank pickup through the carburators. Ensure your tank is vented properly, all fittings are airtight, the primer bulb is firming up, etc. When you pump the primer bulb, does it get hard?.....do you see any fuel coming out of the carbs? Try starting the motor on muffs with the motor down....does it still start as it does when tilted up? Get back to us with that info. Maybe we can help.<br />Backlash
 

Texas Heat

Cadet
Joined
Jul 10, 2002
Messages
27
Re: Where to start

Yes, the bulb gets hard, I havn't checked to see if it is getting to the carb but I did Disconnect the gas line from the motor and gas spewed out and was under pressure. I have not tried to start the motor while it was down @ home and on the muffs. I think it is a fuel problem too. It is flooding out, maybe the bowl float is sticking or the choke is not working. I just do not know.
 

ehenry

Commander
Joined
Jan 6, 2002
Messages
2,393
Re: Where to start

you say the engine will start while tilted upand not when down? Is the tank vent open? Sounds to me like its a fuel/carb issue. Get a rebuild kit. They will come with a fresh float, needle and seat, and other items needed.
 

signus-x

Cadet
Joined
May 28, 2002
Messages
14
Re: Where to start

I was having the same problem, it would start out of water but not in water. It ended up being a blown exhaust tube. Might be something to check.
 

SCO

Lieutenant
Joined
Aug 19, 2001
Messages
1,463
Re: Where to start

Next time it doesnt start, squirt some premix fuel into the carb throats to see if it fires. You say you tighten the gas cap on the water? Have you had success w this engine prior or is this a new engine to you? If you think you are flooded and dont choke it, you might not be getting the fuel into the engine, then later at home enough finally finds the crankcase to start it.
 

Texas Heat

Cadet
Joined
Jul 10, 2002
Messages
27
Re: Where to start

I will tighten the gas tank lid once I am going to start the motor. Yes this is a new motor for me. I was only able to get it to start once and ran it for several hours on the water stoping to fish and re starting the motor with no problems. It is just a cold starting problem I guess. I think it is something simple that I am missing, I might be the "Village Idiot" of the boat world!!
 

SCO

Lieutenant
Joined
Aug 19, 2001
Messages
1,463
Re: Where to start

I don't know what you mean by tightening the tank lid. It must be vented you know to allow air to get into the tank to replace the fuel that goes to the engine. I am trying to help you rule the flooding issue in or out because my engine ('73) fouls the plugs too...nature of the beast that doesnt mean flooding on my engine... and also my experience is that it is tough to get the fuel to the engine on first startup. Gotta have the choke on to shut off air and suck the fuel into the carb throat. On mine the auto choke is not enough, I have to apply full manual choke then crank for a full 6 seconds or more prior to any fire. Keep us posted
 

Texas Heat

Cadet
Joined
Jul 10, 2002
Messages
27
Re: Where to start

So you are saying that I should leave the gas lid loose not screw it down tight? Is that correct?
 

joe steamboat

Recruit
Joined
Sep 24, 2001
Messages
3
Re: Where to start

Based on the size of your boat, you probably have the '72 50 HP electric shift. I have to agree with other posters, it seems like a fuel delivery problem. I don't trailer my boat, it stays in the water all season. Last year, I was having intermittent problems with it much like yours. With no experience, car or otherwise, I rebuilt the carbs. Took about two hours and $50.00 Canadian (About 30 US)for the kits with float. Guess what, it always starts, its faster, and consumes much less gas. If you you want specific advice on rebuilding these let me know.
 

SCO

Lieutenant
Joined
Aug 19, 2001
Messages
1,463
Re: Where to start

There should be a vent somewhere. The cap should be screwed down, but verify that air can get in while running. The tank should have a provision for that. Is it a new OMC plastic tank?
 

SCO

Lieutenant
Joined
Aug 19, 2001
Messages
1,463
Re: Where to start

BTW, because you had pressure when you disconnected the fuel line probably means the bowl is full and the float valve is shut off, ok, good. Could also be clogged fuel filter screen or other restriction so don't feel too good. Once you find you are fuel starved rather than flooded, then go through the carbs. I am with everyone else on this , but it is too easy to confirm with a squirt in the carb throats or cylinders. Could also be a spark or compression issue.
 

Texas Heat

Cadet
Joined
Jul 10, 2002
Messages
27
Re: Where to start

I have an old 6 gal. metal tank and a palstic. The plastic is my back up tank not the main one I use.
 

ob

Admiral
Joined
Aug 16, 2002
Messages
6,992
Re: Where to start

Texas heat.these motors are exhaust tuned and running in driveway on muff is no indication of ruling out carb restriction.Almost all problems inherent to your symptoms are tarnished or gummed orfice related.you'll have to remove the fixed orifices on carbs to check for fuel restriction.you'll also need to remove carb bowls and inspect or replace needle seats.Most motors that sit idle for even two months will develop hard or gummy deposits in carbs. it's just part of owning two stroke motor maintenance.Cab condition is most likely problem and least expensive and easiest to remedy.like I said ,it's a good place to start
 

Texas Heat

Cadet
Joined
Jul 10, 2002
Messages
27
Re: Where to start

Looks like I will be doing a Carb rebuild. I will look around an try to find a parts dealer to get one. What type of $$$ we looking at? If I was going to pay to have thos done by a boat shop, what should I expect to pay? I would like to do it myself but time is something I might be short on. Thanks!
 

KCLOST

Commander
Joined
Jun 22, 2002
Messages
2,095
Re: Where to start

Texas Heat,<br /><br />Before you go tearing into the Carbs, let's make sure you are aware of the vent that should be located on the gas tank cap. Now I don't know much about carb problems because I haven't had any, but if it runs with the gas cap loose and won't when it is tightened down, it sounds like to me and others on this board that the tank isn't vented.<br /><br />There should be a vent on the tank cap, right in the middle of it. You need to open this vent to ensure that air will get into the tank to prevent negative pressure. If not you won't get enough fuel into the engine to keep it running. <br />So my question is, is the vent on the cap open when you try to start it at the lake?
 

Texas Heat

Cadet
Joined
Jul 10, 2002
Messages
27
Re: Where to start

Good question? I never looked! I never did notice such a thing. Is it a piece on the lid that I have to open manually? I mean I ran the boat all day @ the lake once and never had a problem. It is just the starting when cold. I was going to work on it Saturday. I will post what I find out. Thanks all!!!
 
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