350 engine bogging

westcard

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Joined
May 5, 2013
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8
Just purchased boat (used), 1976 24' bayliner Skagit with a 350 omc and volvo 280 outboard, edelbrock 1046 carb. Previous owner stated that the engine bogged when throttle was applied, he had messed with the timing thinking that was the issue. After that he could not get it started. I was able to get it timed and running again, set at 8 deg. as stated in the manual #27 from bayliner. Took it out to the lake with wife and another boat for safety along with several extra fire extinguisher, not know the boat and wanting to make sure that it was safe. Oh, forgot to mention that I was able to get it running in the back yard using a 100 gal trough and lower the outboard into it.

Once on the lake, found out the praws did not work in reverse, (another issue), but engine bogged when throttle is applied. I have read all of the forum posts looking for any that posted the answer to their problem but was unable to find it. Many stated fuel problems so I tried this;

replaced the siphon tube in the fuel tank, replace all fuel lines, installed a backup pump, had mechanical one connected when heading to lake. I removed water separator, and fuel filter, replaced fuel filter with new one. Started great, idled rough for a few minutes then smoothed out as it warmed up. Started increasing throttle in forward engine rev'd up fine until about 2k rpm then began to bog, never reached plane even with WOT, and revs never really increased to 3k or above. Sounded like it was starving for air more than fuel.. switched to electric fuel pump (to rule out failing mechanical pump) started forward again, increased throttle again, same problem. Removed siphon tube from fuel tank, stuck hose directly into tank, started and tried again, same issue.

I have spent a lot of time reading posts and forums about engine bog and that is why i took extra precaution the first time out.

I also read several posts about props, and although not in pristine condition, no edge damage, but paint is cracked along edge of prop and flaking back, I ran my fingers along the props cutting edges and very little ware. Could the prop be causing all of the bogging or if not please give me some idea as to the problem...
 

bonzoscott

Senior Chief Petty Officer
Joined
Jul 26, 2008
Messages
745
Re: 350 engine bogging

What exactly is Bogging? Does it mis-fire or just level out and no more power? I'm not sure Edlebrock carb is OEM so you may need to look into carb rebuild, specifically float adjustment. It may be running the bowl dry at higher RPM. You may also want to check out the distributor. With unknown history, possibly sounds like may not be advancing properly (weights-springs hung up).
 

westcard

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Joined
May 5, 2013
Messages
8
Re: 350 engine bogging

The cap and roter are both new, I replaced them before beginning the timing, did not know what previous owner did so started there along with wires and plugs.

I called Bayliner to get the specs and they told me that the 350 would be OEM and the carb is not what they stated it was when manufactured.

Bogging - lack of power, no additional rpms, and sounds like it is under a lot of load. My dad had a 350 chevy as a kid and I remember the power and roar that came from it, this begins to climb then levels off and no further power.

The bast way I can explain the sound was someone gasping for air. I really felt like it was a choke issue but it has a manual choke and it was wide open.
 
Last edited:

bonzoscott

Senior Chief Petty Officer
Joined
Jul 26, 2008
Messages
745
Re: 350 engine bogging

Easiest things to check first - make sure your throttle plates are opening up all the way by looking down throat of carb while someone moves the throttle forward all the way. And as stated before, assuming it has a traditional distributor, check that weights and springs are not hung up. These are below the base plate in the distributor. Some dis-assembly. Other than that, time to check out carb. If not too mechanically inclined, you may want to have a marine mechanic look at it. Checking throttle plates is easy enough though.
 

westcard

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May 5, 2013
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Re: 350 engine bogging

I am not sure which type of prop I should have on this one.
 

QC

Supreme Mariner
Joined
Mar 22, 2005
Messages
22,783
Re: 350 engine bogging

OK, you need to start with some basics. Although you have done a good job of trouble shooting the fuel supply system, there was no indication that was your problem. At least it is eliminated. Need to start with some basics:

1) You mentioned the previous owner. Are you still in touch with him/her? Can you get any history?

2) You need to read up on prop pitch, and gear ratio. Since this is a frankenmotor/drive combo we can't make any assumptions. Gear ratio and prop pitch determine your "gearing". The engine may be fine, and the prop and gear ratio combo too "tall" for a pretty heavy boat, but we can't tell without more numbers. Prop pitch is usually noted somewhere on the "barrel" or on the end where the prop nut is. Volvos are a little different this way, but you need to scour the prop for numbers.

3) Do you know how to use trim? Does she have trim tabs?

4) You may be overloaded. Get everything out of the boat except safety gear. Everything and retest.

5) That is NOT a marine carb. Read up on that was well. SERIOUS safety issue!!

All of this needs to be understood before we can make serious attempt at figuring this out. The engine may be perfect (minus the carb) but here is no way for us to tell without a lot more info. We can tell you how to confirm gear ratio later, but let's start with the prop pitch. And study up on the carb. This is a big deal. Do you know how to use your bilge blower? read up on that too ;)

Welcome aboard!! :)
 

westcard

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Joined
May 5, 2013
Messages
8
Re: 350 engine bogging

yes i am still in touch with previous owner, he only owned the boat for a short period 1 yr, and from what I got is that it is now running like it did when he got it. He replaced many parts on the motor that needed it, starter, risers, pullies. He stated that these were all purchased from a marine repair shop real close to me. Not much on the previous owner before him.

The prop has the number 15 some symbol then 17, the coating on the prop is blurring the center symbol.

As far as gear, we took everything off, only put in a quarter tank, and had more safety gear mainly fire extinguishers and the rest of the required safety gear. I required the second person so that while driving they could concentrate on nav while I was watching boat and engine reactions.

Trim: it does have an additional trim tail on the outdrive, and one on each side of the stern, all are manual, boat has no trim settings except for 3 positions on the volvo 280. Trying to attach pics....

Yes, using blower before starting and anytime that we sat for a while.
 

Don S

Honorary Moderator Emeritus
Joined
Aug 31, 2004
Messages
62,321
Re: 350 engine bogging

Prop is not your problem with only getting 2000 rpm out of it.

Just a thought here, but have you changed the points? Was the C shaped spring installed with the points? Without that spring, when you get up to rpms around 1600 to 2000 the points stop closing because the spring is missing.
 

QC

Supreme Mariner
Joined
Mar 22, 2005
Messages
22,783
Re: 350 engine bogging

For clarity I think he is saying he is getting 3000 RPM out of it. Prop sounds like a 15 x 17, and thinking this through it probably has the original gear ratio as the drive doesn't sound like it was changed, just the engine.

Pictures may help.
 

Don S

Honorary Moderator Emeritus
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Aug 31, 2004
Messages
62,321
Re: 350 engine bogging

Started increasing throttle in forward engine rev'd up fine until about 2k rpm then began to bog,

Sounded like it happened at 2K to me.
 

QC

Supreme Mariner
Joined
Mar 22, 2005
Messages
22,783
Re: 350 engine bogging

"and revs never really increased to 3k or above."

Not trying to be argumentative in any way, but I can see this being a combination of non-engine things, or a combination of engine and boat stuff (likely). The 17 inch pitch puts me more at ease, if in fact that is what it is. I am less concerned about gear ratio now as well. I am still concerned about trim (manual setting) and I am concerned about the whales tail (I think that's what the "trim tail" is), and I am concerned about trim tab use. Originally he was only going down the engine path, and I saw other warning signs as well. I agree if it hits a wall at 2000 RPM that is not prop pitch. But I could see one hitting the wall at 3000, and it not just being engine as well. What we do know is that the data is suspect, and particularly a diagnosis without a lot more info.
 

westcard

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May 5, 2013
Messages
8
Re: 350 engine bogging

Yes it starts at about 2k but flattens out, or doesn't seem to increase much, at around 3k at wot
 

westcard

Cadet
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May 5, 2013
Messages
8
Re: 350 engine bogging

With the notification about the carb, I am trying to figure out which card i should get.
 

westcard

Cadet
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May 5, 2013
Messages
8
Re: 350 engine bogging

I have included a picture of the stern so that you can see it;

IMAG0122.jpg
 

westcard

Cadet
Joined
May 5, 2013
Messages
8
Re: 350 engine bogging

I ordered a replacement carb for the boat and hoping that it will be here before the weekend. Ordered an Edelbrock 1409 Marine carb. The boat has a Edelbrock manifold on it so is there anything that I should watch for or have to change to place the new one on?
 
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