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  1. M

    Under proped with light load

    The slip at 5100 looks better after some more digging. Thank you for the vessel view recommendation, I just assumed the mpi was too old for that. I found a prop shop an hour from my work, so I will let them recommend a prop since it is returnable.
  2. M

    New to Forum / New Boat / Selecting the correct prop

    You were trimmed out for max rpm, correct?
  3. M

    New to Forum / New Boat / Selecting the correct prop

    I'm really not an expert, but it calculates to 19% slip, which I wouldn't think is terrible for a damaged prop. I guess it depends on how it is bent? Then again, you really have no idea of actual speed. Even if your slip was 10%, you'd only be at 44mph. 4mph accuracy is a lot to ask of that...
  4. M

    New to Forum / New Boat / Selecting the correct prop

    Speedometers are pretty notorious for being way off, especially when they are 30 years old. Either the engine is not running great, or it just can't handle more prop based on rpm. It would be a good ide to check the accuracy of your tach also so you dont end up chasing rainbows.
  5. M

    Under proped with light load

    2007 Tahoe Q7I 20' 5.0mpi alpha one 48 832828a45 17p (aluminum 15x17) With 2 bodies on board and pretty light on gear it does 48mph GPS @ 5500 (verified tach at idle and 2k) Does this sound ok for 6 people and tubing and such? I need to have this prop repaired and wanting to try a different...
  6. M

    Why an increase in engine horsepower will hurt your ‘holeshot’, acceleration and midrange cruising.

    I'm definitely interested what chris finds with a degree wheel. I just can't help but wonder if mercruiser would sacrifice some usable torque just to be able to advertise a bigger horsepower number. Would they even mess with optimising a cam when it is cheaper and easier to use something off...
  7. M

    Why an increase in engine horsepower will hurt your ‘holeshot’, acceleration and midrange cruising.

    I looked for specs on mercruiser cams, and that is a muddy abyss. The fact that you all are saying marine/truck/RV, tells me the cam isn't very critical. A truck cam is good for what, 1600 to 5500 while an RV cam is good from idle to 4400? That is a significant difference in a truck, but I'll...
  8. M

    Why an increase in engine horsepower will hurt your ‘holeshot’, acceleration and midrange cruising.

    You grouped the marine and rv cam together, are you saying they are typically identical? If so, the RV cam is already pretty flat on top and I probably wouldn't want any less overlap or duration than the RV cam. I'm not sure what you mean about getting more "ponies" (HP I assume) out of a...
  9. M

    Why an increase in engine horsepower will hurt your ‘holeshot’, acceleration and midrange cruising.

    The real question is if there are torque gains to be had in a cam swap due to advertising HP numbers.
  10. M

    What is this gel-like substance in my carb? Mercruiser 3.0L Alpha 1

    It looks like someone added marvel mystery oil to the fuel at some point. When it sits in the float bowl, the gas and oil evaporate but the mystery stays behind for the owner to marvel. TLDR; I don't know what that gel is.
  11. M

    Help Diagnosing carb vs ignition problem, 5.7 mercruiser

    If we never hear from you again we will know the carb rebuild worked, or you sunk it for insurance.
  12. M

    Help Diagnosing carb vs ignition problem, 5.7 mercruiser

    I'm leaning towards ignition. I'm not sure what ignition system it has, but I would swap coils, modules, etc between the two engines and see what happens. Coils and modules can get hot and act up, just not as common as a total failure.
  13. M

    Help Diagnosing carb vs ignition problem, 5.7 mercruiser

    Has base timing and advance been verified? I would get that engine off idle every 5-10 minutes, and if it still happens after 20-30 minutes, its probably not the carb.
  14. M

    Cleaning IAC

    I'm not sure what the deal is, but it was fine on the water today. I didn't actually clean it, as it wasn't really dirty at all. I did put a few drops of dry silicone lube on the shaft and tried to work it inside. It still drives me nuts that it cranks for nearly 2 seconds before it fires up...
  15. M

    Cleaning IAC

    The idle is smooth and consistent, and shows 550 on the tac for what that's worth. It has no issues or surging at idle, just returning to idle quickly. The iac shows 10ohms, and is obviously working to some degree.
  16. M

    Cleaning IAC

    On muffs it stumbles pretty good and occasionally dies with a quick return to idle. In gear it stumble really hard and dies if I dont bring it to idle slowly. Probably going to have to order a scanner at this point.
  17. M

    Cleaning IAC

    2007 5.0mpi SN 0W68iforgettherest 2 wire iac. Should the iac be spring loaded? I have seen pics of them with a spring, but mine doesn't have a spring, nor does it stay open or closed, just kinda stays put if I move the valve. Is this normal? Having issues dying when returning to idle.
  18. M

    Getting 1st Covid/Pfizer shot romorrow

    Y'all just had to turn it political. If you think fox is propaganda, but CNN is reputable, that is just nonsense.
  19. M

    Getting 1st Covid/Pfizer shot romorrow

    The CDC confirms those facts, although they are worded more coherently.
  20. M

    Getting 1st Covid/Pfizer shot romorrow

    Let's hope it doesn't turn into a "guess the mutation" game like the flu shot. There have been some pretty terrible guesses with the flu shot that made it essentially useless recently. For me it is easy to forget that some places are still struggling with covid.
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