Boat Won't Start HELPPP!!!

[tolbertn]

I recently purchased a 1980 four winns with a 302 v8. When i went and looked at it the boat started right up. When i got to the launch for the first time it fired then went out. I hit the carb with starting fluid and slammed it into reverse. It ran until i went to go forward and stalled. I proceeded by giving it another shot and went forward and ran it for about 5 min at full throttle. Once again i went back to the dock and tried to dock it when i put it in nuetral just to have it stall again what do i do to get my boat running properly?? where should i start. Thanks for looking
Tolbertn

 

[Lyle29464]

Re: Boat Won't Start HELPPP!!!

Do a search on the operation of the choke and interrupter switch + operating a cold engine at full throttle.

 

[tolbertn]

Re: Boat Won't Start HELPPP!!!

I guess i didnt run it at full throttle just enough to keep the boat running.

 

[tolbertn]

Re: Boat Won't Start HELPPP!!!

Any Other suggestions about my problem??

 

[Raystownboater]

Re: Boat Won't Start HELPPP!!!

Sounds like a Carb or Fuel issue. How long has the boat been sitting? You can start by hooking up a remote fuel tank with fresh gas and see if that fixes the issue. If you are still having problems, think about a carb rebuild and a complete tune up

 

[dubs283]

Re: Boat Won't Start HELPPP!!!

sounds ike the boat starts fine, you just can't keep it running

do you know the proper way to start a carb'd engine??

 

[tolbertn]

Re: Boat Won't Start HELPPP!!!

Well i just bought it and the guy I bought it from "says" he had it out a few weeks ago and it was fine. He started it up for me when i looked at in and ran it for about 30 seconds and shut it off. I had the choke on for about a miniute and it sounded like it wanted to stall so i turned it off and it died. That was probably my bad. I did get it started again but it still didnt want to stay running unless there was a a little throttle applied. I just took out spark plugs and they looked a little gunked up. I also checked the distrubuter wires and one didnt have a good conection.

 

[dubs283]

Re: Boat Won't Start HELPPP!!!

I did get it started again but it still didnt want to stay running unless there was a a little throttle applied. I just took out spark plugs and they looked a little gunked up. I also checked the distrubuter wires and one didnt have a good conection.

tune-up time, and probably a fuel system inspection and testing too

most sterndrive/inboards do not have operator controlled chokes, at least not factory unless they are real old

 

[petermarcus]

Re: Boat Won't Start HELPPP!!!

Sounds like the shift interrupt switch to me, as mentioned above.

Here's the deal -- when you go from forward to reverse there's a switch on top of your engine that cuts off spark to half your cylinders. It acts as sort of a clutch so the gears have time to mesh. Normally, this switch pops on and off in less than a second. If the switch itself is bad, or if the shift cable is kinked or bent or just plain bad, the switch will stay open and the engine will die with only half the cylinders firing. You normally see this when switching between forward and reverse, or vice-versa, or when going to neutral from forward or reverse. So, the most common time I've seen it is when trying to dock when you go back and forth and neutral a lot.

If you know where the switch is (you can see pictures of it if you go to images.google.com and look for shift interrupter switch), you can try fiddling with it if you stall -- you can try to snap it back and see if you can start your engine again. I found out the hard way about it, about 4 miles offshore, but wiggling back and forth between neutral and forward freed it up for me so I could get home.

If it's the switch itself, it's an easy replacement. If it's the cable, it's a little harder as there are some tight squeezes, and sometimes you need to take off the outdrive.

 

[tolbertn]

Re: Boat Won't Start HELPPP!!!

Thanks so much guys. I guess give it a tune up and check the switch and see what happens. I really appreciate it.

 

[dubs283]

Re: Boat Won't Start HELPPP!!!

.Here's the deal -- when you go from forward to reverse there's a switch on top of your engine that cuts off spark to half your cylinders. It acts as sort of a clutch so the gears have time to mesh. Normally, this switch pops on and off in less than a second. If the switch itself is bad, or if the shift cable is kinked or bent or just plain bad, the switch will stay open and the engine will die with only half the cylinders firing.

that is NOT an accurate description of the shift interrupt switch operation, at all

the switch only works when coming out of gear, and disrupts the primary side of the coil thus cutting spark to ALL cylinders, not just half

here is the correct explaination of the shift interrupt switch operation:

http://forums.iboats.com/showthread.php?p=1930449#post1930449

besides, IF it is the shift interrupt switch causing the op's problem, that means its working, it would be a bad shift cable causing it to engage at the wrong time

 

[petermarcus]

Re: Boat Won't Start HELPPP!!!

All cylinders with a Mercruiser, half with an OMC. I didn't mean to be authoritative or pedantic about the number of cylinders on a 1980 V8, just that spark was cut when the switch is triggered. Tolbertn mentioned that it worked "slamming" it into reverse, but died going forward, then later said it died from forward position when going into neutral at dock. I've seen shift interrupt problems matching that description.

95% of the time, I'd agree that it's the cable not the switch, but since the switch is usually up on top, it is a consideration. My own problem a few years ago was debris bending the switch arm. Personally, I just had to remove the debris and bent the arm back and didn't have any more problems with my engine cutting out.

 

[petermarcus]

Re: Boat Won't Start HELPPP!!!

To talk it out a little more practically -- if the problem happens when going through neutral (forward to reverse, reverse to forward, or either forward or reverse to neutral), then I'd look at the switch/cable. If it works fine at half-throttle and dies going to full throttle.... or basically, if it's in the same gear and just dies and you're not transitioning through neutral when it dies, then it's not the switch/cable, it's most likely the fuel system or carb or tune up described above.

 

[Pete104]

Re: Boat Won't Start HELPPP!!!

Yes, there is a problem with description of engine here. Mercury hasn't used a 302 ford in 30 years! However OMC did. & the interupt system they used was pretty accurately described!

 

[dubs283]

Re: Boat Won't Start HELPPP!!!

However OMC did. & the interupt system they used was pretty accurately described!

that would be fine if this were the OMC forum, but this is the mercruiser forum

 

[searay3]

Re: Boat Won't Start HELPPP!!!

Tobertn - what exactly is it you have for power....Merc, OMC, please include a serieal number for the engine and/or drive....seems to be some confusion...

 

[tolbertn]

Re: Boat Won't Start HELPPP!!!

I will check. Im pretty sure that this motor was put in by a previous owner.

 

[sandersps]

Re: Boat Won't Start HELPPP!!!

Tobertn - what exactly is it you have for power....Merc, OMC, please include a serieal number for the engine and/or drive....seems to be some confusion...

I will check. Im pretty sure that this motor was put in by a previous owner.

???????

 

[tolbertn]

Re: Boat Won't Start HELPPP!!!

Here are some pics.

 

[bds85466]

Re: Boat Won't Start HELPPP!!!

That settles that.

If the switch was bad (and not partially stalling the drive), would there even be a chance at going back into neutral with with engine still running?

Part of this sounds symptomatic of a shift cable out of adjustment. I had my lower shift cable go out completely and all I could use was reverse (just rev'd when you put the arm in F!) to get home -- which sucked.

There's plenty of info out there about shift cable adjustments, and even some threads about replacements if I remember correctly.