Bogs when pulling

[TMoNeE]

Hey Guys I posted this in the inboard forum but since a lot of wakeboarders use inboards and pull a lot, this may be a better place,

I'm a fairly new boater, the boat runs great when just cruising and all that, put when im pulling wakeboarders out of the water it bogs and stalls sometimes. I really have to ease into it to keep it from dying which makes it harder to pull the boarders up. This is on a 1991 Sanger DX w/ 350. If i need to provide more info let me know, other than that do you guys have any ideas that would help? Also, the carb was just rebuilt in the off season.

Thanks

 

[craze1cars]

Re: Bogs when pulling

Not a lot of mechanics here. You did the right thing by posting in the inboard section...very knowledgeable people there who will probably give you help.

My first gut guess is the accellerator pump is not functioning properly. This would be directly related to your carb rebuild. Has it been doing this ever since your recent rebuild? If yes, the rebuilder possibly used a generic rebuild kit that came with wrong size accellerator pump, or he didn't hook it up or adjust it properly. And maybe you can adjust the bog out...

Is it even hooked up? Stare down into the carb throat and have someone mash the throttle wide open while you watch. While your helper moves the throttle you should see a very obvious squirt-gun effect of gasoline being shot into the manifold. If you don't see this, it is disconnected. If you CAN see the squirt, is likely not enough due to being improperly adjusted.

I believe you're describing a lean bog. You hit the gas, throttle bores open, air rushes in, and there's not enough fuel for the air to mix with to combust properly. This means you need the accellerator pump to spray more fuel into the carb to mix with that shot of air that occurs every time you give it the gas. I have no idea what kind of carb you have. Some brands have a fairly simple screw/bolt adjustment for this. Others have multiple holes to put linkage to to change the amount of squirt. If you can figure out how, adjust it to pump more fuel and test-drive. If it improves, adjust it further and test drive again.

And again, maybe your rebuilder put a new pump in the carb that is not enough cc's...in which case it can't be adjusted out and you need a larger pump.

And you could have an ignition timing problem. Check your base timing and check for proper distributor advance.

 

[TMoNeE]

Re: Bogs when pulling

Some great info in that post, thanks.

Keep the ideas coming but the suggestions above are a good place to start.

 

[mxfever]

Re: Bogs when pulling

Some great info in that post, thanks.

Keep the ideas coming but the suggestions above are a good place to start.

craze1cars hit it right on the money. I wouldn't even know what else to look at. If the boat is out of water and you're running on muffs it may not do it unless there is a obvious problem with the accelerator pump. Under a load it will take longer for the R's to come up and the need for a good squirt from the pump will become more obvious. I would check this out first. Without a question.

 

[craze1cars]

Re: Bogs when pulling

Stare down into the carb throat and have someone mash the throttle wide open while you watch. While your helper moves the throttle you should see a very obvious squirt-gun effect of gasoline being shot into the manifold. If you don't see this, it is disconnected. If you CAN see the squirt, is likely not enough due to being improperly adjusted.

Just to clarify above...You are to do above check with the engine OFF. I didn't say this. But I'd hate to see someone get hurt...or have you over-rev the engine.

With engine off, you'll see stream(s) of fuel get shot in there plain as day if the accellerator pump is at least functioning...not ripped, not disconnected, etc. But obviously this will not tell you whether it is injecting the correct quantity fo fuel. That can only be identified by experimenting/test driving, or maybe partially by comparing to specs in a service manual.

 

[sickwilly]

Re: Bogs when pulling

Sure sounds like the accelerator pump is not working right. Could be they did not get the right bend on the linkage that activates it, or did not get a good setting on the float, idle or mixture.

Also, the prob with a carb rebuild is they often set it as good as they can after reinstall, but to really dial it in, you need to get the boat in the water with the back pressure on the exhaust and the boat idling forward, and then dial in the idle and mixture. Its also a good idea to do the timing right then too.

Go back to who ever did the carb rebuild and tell them your symptoms.

 

[TMoNeE]

Re: Bogs when pulling

Well, I got in the boat and pulled the cover off and opened the carb throat and hit the throttle, and I dont know what it is supposed to look like but it sure looked like it was spitting plenty of fuel in there. Is there a possibility that it is spitting too much fuel? Or should I maybe take a vid with my phone of how much its spitting and show you guys.

 

[sickwilly]

Re: Bogs when pulling

Nope, no video. You see good streams of gas when the accelerator is pumped, so you can rule that out.

Did it do this prior to the carb rebuild? Why did you do the carb rebuild?

Have you brought it back to the carb rebuilt guys.

On second thought, post a thread in the Mercruiser, OMC, Volvo & other I/O & Inboard Engines & Outdrives section and get some real engine advice.

 

[TMoNeE]

Re: Bogs when pulling

Nope, no video. You see good streams of gas when the accelerator is pumped, so you can rule that out.

Did it do this prior to the carb rebuild? Why did you do the carb rebuild?

Have you brought it back to the carb rebuilt guys.

On second thought, post a thread in the Mercruiser, OMC, Volvo & other I/O & Inboard Engines & Outdrives section and get some real engine advice.

The previous owner had the carb rebuilt, i Bought it in June... in fact the first time I took it out to wakeboard it went fine most of the day then kind of started doing this towards the end of the day... then we went out the last time and it was doing it a lot.

 

[sethjon]

Re: Bogs when pulling

The previous owner had the carb rebuilt, i Bought it in June... in fact the first time I took it out to wakeboard it went fine most of the day then kind of started doing this towards the end of the day... then we went out the last time and it was doing it a lot.

Check the obvious. Change the water sperator and the fuel filter at the carb if there is one.

 

[TMoNeE]

Re: Bogs when pulling

Check the obvious. Change the water sperator and the fuel filter at the carb if there is one.

Yeah my dad said that yesterday, I think ill change those out and see what happens