15mph then nothing?

[QC]

Re: 15mph then nothing?

If a remote fuel supply clears it up that does not necessarily mean it is the tank, or the fuel for that matter. It just means it is not the carb . . . Still could be filter, air leak, fuel itself, anti-syphon valves etc. One thing at a time

 

[BUMP]

Re: 15mph then nothing?

ok fellas, thank you all very much for all your advice, input, and patience! I think i got good grounds to start with. I'm thinking a carb rebuild isn't a bad idea, a buddy said he would do it for a minimal cost. I had one guy tell me to take the carb off and soak it over nigh in carb cleaner.... Think i have it rebuilt, surely it needs it after sitting for 2 years. next, ill replace the fuel lines, and fuel/water seperator again and see if that clears it up. if not all thats left is the fuel pump right? ( other than dirty tank) BTW, were is this " anti siphon valve?? can't find it in my book. THANKS AGAIN!

 

[BUMP]

Re: 15mph then nothing?

Another noob question. Could the prop, or anything in that area ( antiventilation plates) have anything at all to do with any of this? it really seemed as if it had no power, hi rpm's but no push. ( tach doesn't work, just going by ear ) makes alot of noise but doing 15. I tried messing with the trim and all with no change. Just seem right. Prop wasn't changed since last owner took it out. altho a dog chewed on the little wing looking add-ons, but mabey only 1 sq in. was slighty damaged. Im just asskin, because i just read a few things about ventilating lol.. seems like same type of symptoms .

 

[watermellonI]

Re: 15mph then nothing?

Hey Bump
Your anti syphon valve is on the tank generally speakin, it s the fitting where the fuel line attatches to the tank, it will allow fuel to pass but only if its pulled out with suction. So that if your fuel line should rupture or get cut at the tank then it wont leak fuel into the boat.

Yes check your outdrive to make sure its in good shape, you ll need to learn your make and model you should rule out any trouble there first

If you have a spun hub on your prop it could cause some of the problems your describing.

 

[QC]

Re: 15mph then nothing?

Hey BUMP, yeah, what he says ^^^ this is what I was trying to get to when I asked if it revs . . . Now you're saying that it does rev and not go anywhere, right? Dude, we need to start over. If it revs and doesn't go anywhere, how is that almost dying? This could be ventilation too (prop grabbing air instead of water). Do you have a spare prop? If not you need one, go get it and use it to test that end of this deal. Do a search for spun hub and you'll find out how to test that, If it revs and doesn't go, it is either a spun hub, ventilation, or possibly a bad coupler. Most other stuff wouldn't allow the 15 MPH . . .

 

[Fishermark]

Re: 15mph then nothing?

Like the others - I'm confused.

Bottom line - if the motor revs up but the boat doesn't go anywhere - or at least not above an idle speed or so I would suspect a spun prop or bad coupler. If the engine doesn't overheat, I would suspect the prop... if it does I would go with the coupler.

If the engine wants to die and sputter I would suspect the fuel system.

 

[erikgreen]

Re: 15mph then nothing?

erikgreen : Yes sir, i can go all day long at 15 MPH. I do think it's a fuel problem also. What/were exactly is the " fuel pump overflow"? I did replace a clear hose that ran from the back (towards engine) side of the pump to the back side of the carb. The original hose was completly glogged.

When you run the engine, is there any liquid in the clear hose?

Erik

 

[BUMP]

Re: 15mph then nothing?

I'm laughing at myself even... i replaced the clear hose with a black hose so i couldn't tell ya. I'm going to adjust the throttle cables as i have read here, and clean the carb. At that point i will take it back out. If its still doing the same thing, I will make a video of the entire event. THAT , I bet , will eliminate alot of confusion coming from my end, i hope. i spent all day reading posts about various things. I am still learning, and still reading. my bad for getting a OMC cobra..hey, it was free. When i get it squared away ( and I will)
I shall buy you all a beer of your choice!

<><><><><><><><><><><><><><><><<<><><><><><><><><><><><
RECAP of events as i remember them ( I read some of my own post...i'm sorry)


- I give it the throttle ( tried it fast and slow)
- i get to about 15 mph ( give or take)
- when i throttle past that point, it gives in. ( no more go, slips , everyone fly to the bow if standing)
- i QUICKLY bring the throttle back to neutral in fear it will stall. (didn't give it a chance to stall)
- did this many many times thruout a 2 hour time period, some times i would cruise 20min or so before attempting to go faster again.

<other possibly useless information>
-the wake at 15mph was huge, like a rooster tail, fat and about a foot tall than the back of the boat. ( i thought i didn't know how to trim properly, but ran it thru the motions as i was running 15 mph)

-Tach is broken, rpms i'm not sure of. Throttle was at about the 3/4 way to being parallel to the deck. if i were to guess, id say 2500-3000rpm no less

engine did start to overheat a few times, particularly in no wake zone and running with the waves, running into the wind( into the waves) temp was ok. It did this most the first 30 min or so, the was ok till was in no wake zone again.

 

[D445547]

Re: 15mph then nothing?

Hey BUMP, yeah, what he says ^^^ this is what I was trying to get to when I asked if it revs . . . Now you're saying that it does rev and not go anywhere, right? Dude, we need to start over. If it revs and doesn't go anywhere, how is that almost dying? This could be ventilation too (prop grabbing air instead of water). Do you have a spare prop? If not you need one, go get it and use it to test that end of this deal. Do a search for spun hub and you'll find out how to test that, If it revs and doesn't go, it is either a spun hub, ventilation, or possibly a bad coupler. Most other stuff wouldn't allow the 15 MPH . . .

EXACTLY!!!

 

[Coors]

Re: 15mph then nothing?

I'm laughing at myself even... i replaced the clear hose with a black hose so i couldn't tell ya. I'm going to adjust the throttle cables as i have read here, and clean the carb. At that point i will take it back out. If its still doing the same thing, I will make a video of the entire event. THAT , I bet , will eliminate alot of confusion coming from my end, i hope. i spent all day reading posts about various things. I am still learning, and still reading. my bad for getting a OMC cobra..hey, it was free. When i get it squared away ( and I will)
I shall buy you all a beer of your choice!

<><><><><><><><><><><><><><><><<<><><><><><><><><><><><
RECAP of events as i remember them ( I read some of my own post...i'm sorry)


- I give it the throttle ( tried it fast and slow)
- i get to about 15 mph ( give or take)
- when i throttle past that point, it gives in. ( no more go, slips , everyone fly to the bow if standing)
- i QUICKLY bring the throttle back to neutral in fear it will stall. (didn't give it a chance to stall)
- did this many many times thruout a 2 hour time period, some times i would cruise 20min or so before attempting to go faster again.

<other possibly useless information>
-the wake at 15mph was huge, like a rooster tail, fat and about a foot tall than the back of the boat. ( i thought i didn't know how to trim properly, but ran it thru the motions as i was running 15 mph)

-Tach is broken, rpms i'm not sure of. Throttle was at about the 3/4 way to being parallel to the deck. if i were to guess, id say 2500-3000rpm no less

engine did start to overheat a few times, particularly in no wake zone and running with the waves, running into the wind( into the waves) temp was ok. It did this most the first 30 min or so, the was ok till was in no wake zone again.

Does it slip? or just lose power? This matters a lot.

 

[BUMP]

Re: 15mph then nothing?

lose power.

 

[Coors]

Re: 15mph then nothing?

http://forums.iboats.com/showthread.php?t=167561

 

[BUMP]

Re: 15mph then nothing?

Roger that. I've read it,understand it, and printed it out for reference later. I guess I would have to take it to the lake in order to put it on a load? Unless there is a trick I don't know of to do it in my driveway. Thanks Coors for your patience and advice. thanks to all you guys.

 

[QC]

Re: 15mph then nothing?

lose power.

Alrighty then. Important distinction. What we were worried about was anything that sounded like it was slipping. Fact is that could be nothing to something pretty big . . . back to your irregularly scheduled program . . .

 

[Don Ayd]

Re: 15mph then nothing?

Try taking of the gas cap. If the fuel tank vent is clogged it could cause the same type symtom. Also when the shift interrupter switch or shift cable is out of adjustment or binding it you will loose half the power as the switch allows the shift module to cut out two cylinders at a time. If this is happening at the time the problem occurs the boat would never get on plane, its like taking half the power away or similarily disconecting two spark plug wires and attempting to run the boat. Try disconnecting the shift interrupter switch to see what happens. It has a connector you can disconnect near where the shift cables are on the engine. Disconnecting this will cause the engine to stall when coming out of gear or not to be able to get it out of gear without increased effort on the shift handle to get it out of gear, so be for warned of this. If you want to be some what daring and want to experiment a little go and disconnect two sparkplugs on a four cylinder car and attempt to drive it you'll tell pretty fast what the result will be.--- this may be whats happening with your boat.