Rpm issue ideas.... I'm lost....
08-09-2016, 04:43 AM
#13
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Both engines have MSD ready to run dist, my engines were BOTH dynode in full marine trim as they sit in boat, even my Stainless marine exhaust, oil is fine, all is fine and identical on engines like I said they are .3TQ apart and 3 hp apart... I have seen full rpm with this drive, not often but I have, so I don't thin k the drive would vary the rpm..
hydraulic roller lifters correct. What kind? What are you using for ignition? Did you try swapping those out. Otherwise throw a simple HEI on the engine down on rpm. Also did you dyno engines with your ignitions your currently using. I only ask cause some dynos are set up to use their own. Oil looks same in both engines. Cut open filter on down rpm engine. I'm just throwing that out there. Sure it's fine but rule it out anyway. Drives feel good and spin the same after warmed up in neutral on trailer.
If you ruled out pretty much all the above maybe reset valve lash.
If you ruled out pretty much all the above maybe reset valve lash.
08-09-2016, 04:45 AM
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Not many dyno as they are in the boat like I did..
https://m.youtube.com/watch?v=KqmM7YHqnaE
https://m.youtube.com/watch?v=F5sQmgFHOf4
https://m.youtube.com/watch?v=KqmM7YHqnaE
https://m.youtube.com/watch?v=F5sQmgFHOf4
08-09-2016, 05:49 AM
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Swap carbs. Run it and see if it makes a difference. I rebuilt one of my motors a week ago do to Mechanical Advance in MSD not advancing and dropped an exhaust valve. (Distributors are locked now).The motor that dropped the valve was always the stronger of the two. When I rebuilt the motor I went from flat tops to a dished piston. (Getting ready for winter project) lost a full point of compression in the motor. Took it out an ran it this past weekend. Guess what... That motor is still stronger still accelerates harder than the other motor even with full point less compression. I figured the thing was going to be a turd.
08-09-2016, 06:23 AM
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Did you have any work done to your drives? If so, is it possible that one is set up tighter than the other? Also what about the condition of the running surface in front of each drive, any thru hulls, gouges ect? Any of these could induce air into the prop and cause higher RPM on that engine.
08-09-2016, 06:47 AM
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I did do a lower gear on port drive but pretty sure I seen equal rpm since that, we did also verify proper overall resistance in the drive and was well within spec, if it comes down to it I will swap with another left drive I have 3 spares... Even spinning by hand I don't feel it different tben other.
Hull and all that is fine the boat always hit 5500 before nothing changed on hull, water pick ups or any of that.
You guys will see why I am going insane trying to figure it out!
Hull and all that is fine the boat always hit 5500 before nothing changed on hull, water pick ups or any of that.
You guys will see why I am going insane trying to figure it out!
