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Thread: Altitude????

  1. #1
    ELIMINAT THIS
    We were at lake berryessa 2 weeks ago,it was running super rich (smell and black transom) it was slugish and I lost 300 to 400 rpm. I was told berryessa is 2000'. Is this normal or should I think about rebuilding my carbs. 509 with a 8-71 running 6psi 91 octane. thank you.

  2. #2
    ELIMINAT THIS
    Thanks Dragboat I called the marina they confirmed 500'.So I guess im going to pull the carbs for a rebuild.

  3. #3
    Robbie Racer
    The density altitude is what affects your fuel mixture. That takes into affect, altitude, air temperature and humidity. The lake may be only 500' but I have seen 4,000' density altitude on my weather computer in the heat of the summer. It was pretty muggy a couple of weeks ago at Berryessa when we were there. I didn't take a weather reading but to me it felt like it was in the 2,000' corrected altitude area. Do you think it's running rich at an idle or at WOT? You might want to do a plug check after a WOT run. (Shut it off quickly after the run and don't let it idle to screw up your plug reading). If your plugs look rich, then you can probably try reducing the main jet size by one size all around. Do you have power valves? If so, you might want to check those too if it is rich at an idle. I blew one last year and it was open all the time and caused my motor to run very rich at an idle until I replaced it. That's my .02. Good luck, RR

  4. #4
    deltarat
    Wow I really thought that lake was higher than 500 ft. I do think Keith is on to something here, it was quite muggy that day.

  5. #5
    mirvin
    Allright, I'm just gonna come out and say this. Berryessa is cursed...... Seriously, I've never had a boat run right there.
    mirvin

  6. #6
    ELIMINAT THIS
    Well mervin I will find out tommorow. I have not had time to do any thing to the carbs.RR thanx for the info. Delta Rat thanx for the bogus info.j/k

  7. #7
    Craig
    Hey when you gonna learn how to use a digital camera and shoot me some pic's of that 28
    Craig

  8. #8
    ELIMINAT THIS
    Craig I still have your email let me know if I can send them on snap fish that is the only chit I now how to do.Mervin maybe you were wright.It ran great last weekend Myself and Racer52 made some nice 100mph runs. Very little black on the transom ? RR if I make it to shasta for the cat attack do you have any sugestions on tune up. what is the altitude or just leave it and hope it was the curse of berryessa like mervin said.

  9. #9
    Robbie Racer
    Craig I still have your email let me know if I can send them on snap fish that is the only chit I now how to do.Mervin maybe you were wright.It ran great last weekend Myself and Racer52 made some nice 100mph runs. Very little black on the transom ? RR if I make it to shasta for the cat attack do you have any sugestions on tune up. what is the altitude or just leave it and hope it was the curse of berryessa like mervin said.
    I will have my weather computer with me at Shasta and should be able to get some good density altitude readings. The black on the transom can be misleading. It can be coming from two rich of an idle mixture or it can happen if your main jets are sized to large for the air conditions. It will be helpful if you can figure which of the two is causing the black on the transom. Have you done a plug check yet after a good long WOT run to see what they look like? That will help narrow it down. If you make it to Shasta we can talk about it in more detail.
    RR

  10. #10
    ELIMINAT THIS
    Thanks Keith.Before we went out last weekend I didnt have time to look at anything since berryessa.It was running fat there couldnt get it over 5400 rpm 2 people light fuel. Delta last weekend 4 people 80-100 gallons of fuel 5900-6000 rpm very little or the normal amount of black on the transom.I will be in shasta late fri. see you there.

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