Boat cuts out when throttling up

[Sugarbug]

Yeah. For about 15 minutes

 

[Emperor]

Here are a few shots with the air cover off. Tell you anything?

View attachment 33969View attachment 33968View attachment 33967

Tells me, you don't know how to orient your camera when taking pictures, but that's neither here nor there.

That's an oldie. I haven't seen a manual pull choke outboard in a long time. In this case you are definitely dealing with a "fuel" issue. Start all the way at clean debris free tank (before gas), and work you way toward the carb. This motor is too old to have sensors affecting the performance.

 

[carlosd321]

I would listen to Emperor and also run some seafoam through it for a bit and go from there. make sure your connections are tight at the bulb and filter. I wont be suprised if eventually you make it back to the carb. Most boat motor issues are carb issues IMO

 

[Gus McCrae]

Oh, you can try spraying a little carb cleaner on the outside of the carb when it is running. The liquid will fill any leaking gasket for a moment and the engine will change speed (you will hear it). That will help you figure out where/if there is a leak.

 

[Golden-Eagle]

Not trying to beat a dead horse. A bad fuel bulb will do the same thing. I have seen them collapse when under a load. Seafoam first is definitely in order to purge the system.

 

[carlosd321]

X2 and make sure your air valve on your tank isnt screwed closed! Assuming you have a plastic tank.

Not trying to beat a dead horse. A bad fuel bulb will do the same thing. I have seen them collapse when under a load. Seafoam first is definitely in order to purge the system.

 

[Sugarbug]

Bulb is new and isn't collapsing. I started her up again and she let me throttle up. Turned her off and back on and then she would die if I tried to throttle.

 

[3fifty7]

I have a Yamaha, so I know nothing about the problems of which you speak.



Sorry had to.
I have had a similar symptoms when my carbs got out of sync. Doesn't really apply here.
With as much other work as you have done with this boat I know how frustrating when it won't come together. But old outboards are very temperamental.
Follow the advice you have already been given and you'll find where the trouble lies.

 

[Sugarbug]

Stuck at home while my daughter takes a nap. Will run out for some sea foam ASAP.

 

[Emperor]

I have a Yamaha, so I know nothing about the problems of which you speak.

Funny thing; I know how to fix these old motors. Just chose to buy a "Yami" instead myself!

 

[DiggerP]

Bug,

If you don't have it fixed by tomorrow, give me a call. I'll PM you my business phone. I'm out in the morning for the dentist (oh, joy LOL!). I own a boat-parts company and will be happy to help guide you if I can.

DiggerP

 

[Emperor]

Stuck at home while my daughter takes a nap. Will run out for some sea foam ASAP.

Just hang a note from her mobile telling her if she wakes up, Daddy will be right back!

 

[Sugarbug]

Oh, you can try spraying a little carb cleaner on the outside of the carb when it is running. The liquid will fill any leaking gasket for a moment and the engine will change speed (you will hear it). That will help you figure out where/if there is a leak.

This happened. If I spray it into the carb, it will kill it. If I spray it outside (anywhere near the motor), the RPM's will pick up.

WHAT DO I DO?!?!

 

[Sugarbug]

Yay it runs!

So I went out to mess with it some more and when I cranked it, it cranked really slow like your car does when your battery is nearly dead. So I decided to yank the battery out and go charge it. When I touched the wing nut on the motors battery cable I began speaking in tongues!! That sonbitch burned the hell out of me. For some reason sitting on that terminal (there are two on the battery for positive and two for negative) it couldn't handle the draw of amps and heated up a good 200-300 degrees (blisters to prove it).

I thought that was odd, but decided to throw them on the other terminals. Now it starts right up, idles, revs... Freaking amazing. Gladly pay a couple burned fingers for it to work. Not sure if its just a temporary fluke, but I'll check again in the morning.

 

[general mills]

I'm not to knoledgeable on boats, but I work on cars, bikes and jets often. If charging the battery fixed the problem, check the voltage going to battery at idle and at throttle. A bad voltage regulator (on modern stuff, usuallt a rectifier/regulator unit or all in the alternator) can cause it to make voltage at an idle, but drop voltage as rpm (alternator frequency) picks up. If it is a 12 volt system, you should run over 12V at idle and arond 13.5-14.5 at speed. If the problem I am describing is happening, you will be running 12V at idle, then, as your battery dies down, it will drop voltage to below 12V as engine speeds up. The electrical system will feed off the battery untill the voltage drops to low to give good spark at speed, but will run fine when returned to Idle. If you know how, disconnect the feed from the alternator/rectefier/regulator/whatever your set up is and mesure the voltage that is feeding the battery while running. I've seen this problem most often when motorcycles are jumped off running cars, as the higer power charging system will fry the smaller system's delicate components. bike will run fine at an idle, but sputter and dim all the lights bad when reved, then run fine when returned to an idle. I've had to ride one home that way for miles and it is a pain. Idle while coasting to build up enough charge to give you one burst of speed for about 2 sec, then idle and coast.

 

[Gus McCrae]

This happened. If I spray it into the carb, it will kill it. If I spray it outside (anywhere near the motor), the RPM's will pick up.

WHAT DO I DO?!?!

I'm not sure I made myself clear. Anything going into the carb through the air horn (how all the air enters the engine) doesn't mean much. What I was suggesting was to spray directly on the outside of the carb in little localized areas to see if one of the assembly gaskets was leaking air into the engine. The fluid temporarily plugs that hole and you will hear the engine change speed. If it's not leaking, it won't change speed..... But, you have to be careful not to let the carb cleaner into the air horn otherwise it will end up in the engine that way and may change engine speed.

The point is to find a gasket, crack, or unused/unplugged port leaking extra air into the engine.


In college, we had a buddy with a Mazda truck that had this problem and it needed a rebuild. He needed the truck for the semester and couldn't do the rebuild right away. We sprayed the leaking spot with engine paint and let it dry/harden. He drove it for the rest of the semester until he got home to rebuild it. It was a bit redneck, but I was kind of proud of that idea.

 

[Sugarbug]

I'm not to knoledgeable on boats, but I work on cars, bikes and jets often. If charging the battery fixed the problem, check the voltage going to battery at idle and at throttle. A bad voltage regulator (on modern stuff, usuallt a rectifier/regulator unit or all in the alternator) can cause it to make voltage at an idle, but drop voltage as rpm (alternator frequency) picks up. If it is a 12 volt system, you should run over 12V at idle and arond 13.5-14.5 at speed. If the problem I am describing is happening, you will be running 12V at idle, then, as your battery dies down, it will drop voltage to below 12V as engine speeds up. The electrical system will feed off the battery untill the voltage drops to low to give good spark at speed, but will run fine when returned to Idle. If you know how, disconnect the feed from the alternator/rectefier/regulator/whatever your set up is and mesure the voltage that is feeding the battery while running. I've seen this problem most often when motorcycles are jumped off running cars, as the higer power charging system will fry the smaller system's delicate components. bike will run fine at an idle, but sputter and dim all the lights bad when reved, then run fine when returned to an idle. I've had to ride one home that way for miles and it is a pain. Idle while coasting to build up enough charge to give you one burst of speed for about 2 sec, then idle and coast.

Didn't charge it at all. Just changed terminals.

 

[Sugarbug]

I'm not sure I made myself clear. Anything going into the carb through the air horn (how all the air enters the engine) doesn't mean much. What I was suggesting was to spray directly on the outside of the carb in little localized areas to see if one of the assembly gaskets was leaking air into the engine. The fluid temporarily plugs that hole and you will hear the engine change speed. If it's not leaking, it won't change speed..... But, you have to be careful not to let the carb cleaner into the air horn otherwise it will end up in the engine that way and may change engine speed.

The point is to find a gasket, crack, or unused/unplugged port leaking extra air into the engine.


In college, we had a buddy with a Mazda truck that had this problem and it needed a rebuild. He needed the truck for the semester and couldn't do the rebuild right away. We sprayed the leaking spot with engine paint and let it dry/harden. He drove it for the rest of the semester until he got home to rebuild it. It was a bit redneck, but I was kind of proud of that idea.

Oh I see. If it gives me anymore fits I'll give that a try.

 

[Gus McCrae]

Didn't charge it at all. Just changed terminals.

Short? Are the terminals for different voltages or purposes? I don't know a lot about boats.

 

[Tsharp]

Try this pull the choke out while the engine is running then try speeding up if it does speed up then it is the high speed jet.