CARB REPLACEMENT DIDN'T WORK- I THINK I FOUND SOMETHING

[FreeBeeTony]

Re: CARB REPLACEMENT DIDN'T WORK- I THINK I FOUND SOMETHING

I put a vacum gauge on it and it looked fine.......19-20, pretty steady.<br /><br />I know Don.............it's just that I don't have an easy way to pull the boat out right now.<br /><br />And yes Nick has the same problem........and he pulled is O/D and found nothing.........that's what I am afraid of.<br /><br />Would the vacum gauge test show this type of blockage?

 

[ntheyer]

Re: CARB REPLACEMENT DIDN'T WORK- I THINK I FOUND SOMETHING

Just a question to all... Not to be a pain about this but, how long does the fuel in the float bowl last at WOT? If the fuel pump was weak, wouldn't the engine run for one or two seconds at WOT out of the hole from idle on the fuel in the bowl before starving? Or does the bowl empty almost instantly without adequate pressure from the pump? The problem I have is that my fuel line from the pump all the way to the carb is metal. There is no way for me to splice in a fuel pressure tester on my engine. I actually don't have a lot of money and can't really afford just buying a new pump if that is not the problem. (Getting married in four weeks). Sorry for confusing the issue. In terms of the exhaust being plugged. I pulled the leg yesterday and found nothing. I looked in it as well as I could, but couldn't find anything. All three exhaust ports blow water and exhaust freely, so I don't think I have any obstruction. Maybe it is the fuel pump???

 

[Ralph 123]

Re: CARB REPLACEMENT DIDN'T WORK- I THINK I FOUND SOMETHING

FreeBeeTony - Have you considered a boat hauler? They'll pull the boat and put it on jack stands (they'll rent them to you) any where you want it for a reasonable fee (say $100 - $150) depending on where you want it and their minimum. I'm sure there are a bunch listed in the Long Island Yellow Pages.

 

[rattana]

Re: CARB REPLACEMENT DIDN'T WORK- I THINK I FOUND SOMETHING

One last question, what does the vacuum gauge do when you try to hold it at the RPM where it bogs?

 

[Buttanic]

Re: CARB REPLACEMENT DIDN'T WORK- I THINK I FOUND SOMETHING

If it is too much fuel the plugs will be carbon fouled black. How do the plugs look? If they are light brown or white it is not too much fuel. A vacuum gauge will tell you if it is an exhaust restriction. Starting with the engine at idle, slowly increase engine speed to 3,000 RPM, engine vacuum should be equal to or higher than idle vacuum at 3,000 RPM. If vacuum decreases at higher engine RPM's, an excessive exhaust back pressure is probably present.

 

[ntheyer]

Re: CARB REPLACEMENT DIDN'T WORK- I THINK I FOUND SOMETHING

When I looked at mine, they were definitely soaked and black. No backfiring either. The other thing is that I just replaced my engine oil yesterday and definitely had a gas smell and gas in the oil. This is from trying to run the engine through this 'bog'. I sure over time (100 hours) of trying to work through this issue, some fuel has blown by the rings when soaking the pistons. I definitely feel like it's rich, not lean. All indications lean to rich. The wierd thing is that it is fine until about 3/4 throttle or, 3200 rpm. Beyond that, it's too rich. In a previous post I said that I even jetted down on my mains by two sizes and it didn't change the symptom at all.

 

[FreeBeeTony]

Re: CARB REPLACEMENT DIDN'T WORK- I THINK I FOUND SOMETHING

I thought that vacum went down as rpm's increased?

 

[Trent]

Re: CARB REPLACEMENT DIDN'T WORK- I THINK I FOUND SOMETHING

I know this deals with automotive but it should help some....<br /><br /> web page

 

[Don S]

Re: CARB REPLACEMENT DIDN'T WORK- I THINK I FOUND SOMETHING

Take it out and try it again, if the vacuum gauge drops to zero and stays there at 3200 rpm, then you either have a dirty bottom causing the boat to act overloaded or you have an exhaust restriction.

 

[FreeBeeTony]

Re: CARB REPLACEMENT DIDN'T WORK- I THINK I FOUND SOMETHING

So you guys are saying that the vacum should stay high (~20) even up to 3200RPM? I thought that vacum decreases at higher RPM? Or does it only decrease when you are accelerating and go back up at a steady RPM?<br /><br />I am going to try this tonight before we try to watch some fireworks on the water.......<br /><br />I hope I find something!

 

[FreeBeeTony]

Re: CARB REPLACEMENT DIDN'T WORK- I THINK I FOUND SOMETHING

I THINK I FOUND SOMETHING!!!!<br /><br />Here are my results:<br /><br />These are the vacum readings at different RPM's:<br /><br />1) 600 @ idle: 19<br />2) 1000 (in gear) 16.5<br />3) 1500 17<br />4) 2000 15<br />5) 2500 13.5<br />6) 3000 11<br />7) 3200 9<br />8) when bog occured and I gave it more throttle the vacum went to 2<br /><br />Is this a clear indication of an exhaust restriction? Or could it still be something else?

 

[Don S]

Re: CARB REPLACEMENT DIDN'T WORK- I THINK I FOUND SOMETHING

Yes!

 

[ziggy]

Re: CARB REPLACEMENT DIDN'T WORK- I THINK I FOUND SOMETHING

i think dons just posted that it was either a dirty bottom or a exhust restriction if it drops to 0 at the bog. yor went to 2hg. perhaps ya could try a little swim with a scuba mask and snokel to confirm that the bottom is not dirty as suggested w/o removeing it from the water. if clean then yer down to the exhust restriction. i'm just reading..........sounds like yer gettin close perhaps though, were all rootin for ya...........

 

[bigdaddyofhouse]

Re: CARB REPLACEMENT DIDN'T WORK- I THINK I FOUND SOMETHING

pull the damn thing out of the water and have it fixed !

 

[FreeBeeTony]

Re: CARB REPLACEMENT DIDN'T WORK- I THINK I FOUND SOMETHING

I guesss I have to make arrangements to get it out of the water.<br /><br />Wish I would have known about this test 2 weeks ago!

 

[rattana]

Re: CARB REPLACEMENT DIDN'T WORK- I THINK I FOUND SOMETHING

Another idea is the timing. Did you check that it is advancing through the RPMs from idle to 3000 RPM? Just another idea before you go to the trouble of pulling your boat out of the water.

 

[FreeBeeTony]

Re: CARB REPLACEMENT DIDN'T WORK- I THINK I FOUND SOMETHING

Timing was defintly advancing through 3000RPM.<br />I taped a piece of colored paper with increments on the damper and monitored it with a light while my son operated the boat.

 

[rattana]

Re: CARB REPLACEMENT DIDN'T WORK- I THINK I FOUND SOMETHING

okay good, I was just throwing ideas out.

 

[ntheyer]

Re: CARB REPLACEMENT DIDN'T WORK- I THINK I FOUND SOMETHING

Just to let you know, I did take everything apart today. I split the outdrive, took out the riser and ran a pipe cleaner through everything, including the gear housing. Absolutely no obstructions. I also ran a pipe cleaner through the manifold on the exhaust side and found nothing. So I still have the same issue. Where else might I have an exhaust restriction? By the way, my flappers are completely removed. There is nothing in the exhaust system at all.

 

[Richard Petersen]

Re: CARB REPLACEMENT DIDN'T WORK- I THINK I FOUND SOMETHING

If it is at all possible. You have a defective RPM rev limiter. What else can be so accurate?