Still Bogging.....even after taking it to mechanic

[Nathan S]

===

 

[iwombat]

Re: Still Bogging.....even after taking it to mechanic

From what you describe, your plugs are telling you that you've got a mixture problem. Let's assume for a moment that your carbs are nice and clean (It still may be the case that they aren't, but lets look elsewhere first). Possible culprits would be a defective primer solenoid, or clogged recirc valves. Those are pretty easy to check.

 

[Nathan S]

Re: Still Bogging.....even after taking it to mechanic

I believe the primer solenoid is operational. It works when you push the key in and quits when it is not pushed in. I will check it for sure when I get off work this evening. As for the check valves I actually replaced all of the ones that were not recessed in the crank case (Forgot to add that). There was one broken one and I wasnt happy with how a couple other operated. The ones in the crank case were functional. I did initially have a recirculating hose wrong, but I have all those correct now and it was corrected before taking it to the shop.
Thanks!

 

[iwombat]

Re: Still Bogging.....even after taking it to mechanic

I've never had it happen, but I believe there's some diaphragms in the solenoid that if torn or worn will cause it to leak into the cylinders once a vacuum builds up. Try a search, or maybe someone else with more information will chime in here soon.

 

[Faztbullet]

Re: Still Bogging.....even after taking it to mechanic

If it is not spitting at idle, make sure you have about 1/16 space between throttle roller and cam, up mains .002 and downsize pullover jet .003. Try either tapping choke while planing off or plug pull overs with tooth pick. If it stops bogging richen idle.002 and pull over.003.

 

[Nathan S]

Re: Still Bogging.....even after taking it to mechanic

Faztbullet, it doesnt spit at idle and there is a slight gap between the cam pickup. I am not sure what the pull overs are? Are these where the primer adds the extra gas?

 

[Lone Duck]

Re: Still Bogging.....even after taking it to mechanic

Shouldn't the fuel mix be 50:1 ? Try leaning jets 1/4 turn . Don't know much about that particular engine. Don't just turn the carbs upside down to check, make positively sure your floats are at the correct height.

 

[petryshyn]

Re: Still Bogging.....even after taking it to mechanic

Before I got the boat/motor the VRO was removed so everything is premixed. And it runs on a holley electric fuel pump at about 8psi

I would guess the electric pump is overpowering the needle/seats and floats. It is likely causing too high of a float level and flooding the engine. Disconnect the electric pump and see if it improves with running it on the primer ball alone. If it does, replace the pump with a pulse type replacement....

 

[Faztbullet]

Re: Still Bogging.....even after taking it to mechanic

No the pullover jets or intermediate jets as proper name is the small jet on carb at 11 o'clock and idle jet is at 7 o'clock. Try the tapping choke trick, bet it helps.

 

[Dhadley]

Re: Still Bogging.....even after taking it to mechanic

Nathan, you are running this with the airbox on, right? What spark plugs are you using?

 

[Nathan S]

Re: Still Bogging.....even after taking it to mechanic

Yes the airbox is on. I did notice when it came back from the shop they had not put the air box gasket back on, if that matters? Champion plugs QL177 I think. I will double check, but it what whatever the manual called for.

Lone Duck, we are still in break in so thats why its 25:1

petryshyn there is no fuel primer bulb. It ran like this before it was rebuilt with no problems, but I can drop the pressure some if need be.

 

[Azonic]

Re: Still Bogging.....even after taking it to mechanic

I am going to say the fuel pump is over doing it on the float seats and forcing to much fuel in the bowl...

When this happens you can run WIDE open with no problem, but idle speeds just flood the carbs...

 

[Dhadley]

Re: Still Bogging.....even after taking it to mechanic

Agreed, lose the electric pump (I missed that part). Don't try to out guess OMC engineering on fuel delivery. Some other areas, yes - but not on fuel delivery.

 

[Nathan S]

Re: Still Bogging.....even after taking it to mechanic

Ok. Just curious why it would change now, when it ran fine on it for the last couple of years? It was this way when I got it. Any ideas as to why?

 

[kenmyfam]

Re: Still Bogging.....even after taking it to mechanic

Ok. Just curious why it would change now, when it ran fine on it for the last couple of years? It was this way when I got it. Any ideas as to why?

Maybe a combination several previous wrongs made it run O.K. Stranger things have happened.
Lose the electric fuel pump. Disaster waiting to happen in my opinion.

 

[Nathan S]

Re: Still Bogging.....even after taking it to mechanic

I havent got a new pump yet, but I did notice that tapping the primer will help keep it alive at idle, will allow for fast idling with the hot foot, and will also help it overcome the bogging without the need to rev it up and "clear it out."

 

[daselbee]

Re: Still Bogging.....even after taking it to mechanic

Take a small vise grip and lightly clamp off the fuel input side of the primer solenoid. This shuts off the gas flow TO the solenoid, and will prove if it is leaking excess fuel into the back of the intakes.
Do this after you get it started the first time, because you will never get it started if you clamp it off and then try a cold start.

 

[petryshyn]

Re: Still Bogging.....even after taking it to mechanic

Before I got the boat/motor the VRO was removed so everything is premixed. And it runs on a holley electric fuel pump at about 8psi

Did you actually measure the fuel pressure to be 8 lb, or just guess?
Now it sounds like a fuel pressure/supply problem.....

 

[daselbee]

Re: Still Bogging.....even after taking it to mechanic

If it is not spitting at idle, make sure you have about 1/16 space between throttle roller and cam, up mains .002 and downsize pullover jet .003. Try either tapping choke while planing off or plug pull overs with tooth pick. If it stops bogging richen idle.002 and pull over.003.

Faztbullet...can you please give me a detailed explanation of the intermediate circuit on these carbs? I see a very small pickup tube that extends down into the bowl and feeds gas to the int. side plate / labyrinth where int. mixture is done. If you increase the int. jets, will that give more fuel (riicher), because it allows more air thru that labyrinth and draws more fuel?
Seems that is the way it works...
Anything you can add to help me understand will be greatly appreciated.

 

[Faztbullet]

Re: Still Bogging.....even after taking it to mechanic

smaller jets =richer on both circuits. What size jets do you have now? the best I have found on a .030 motor is 33 idle and 30 inter.