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-   -   Rpm issue ideas.... I'm lost.... (https://www.offshoreonly.com/forums/general-q/340112-rpm-issue-ideas-im-lost.html)

monster12valve 08-09-2016 07:06 PM

im trying to think... Everything different between the boat and the dyno... Waves... Vibrations.. Angle.. Drives... Trans

getrdunn 08-09-2016 07:10 PM

Might come to doing a compression and leak down unless you already have. I realize their fresh engines but...

monster12valve 08-09-2016 07:20 PM

Sounds dumb... But thinking out loud.. Do TRS have the fin anodes above the prop? Possible it kicked sideways when drive was out back on?

Full Force 08-09-2016 07:21 PM

I did in fall both engines all 16 within 5 psi across board ..


Originally Posted by getrdunn (Post 4469019)
Might come to doing a compression and leak down unless you already have. I realize their fresh engines but...


donzi matt 08-09-2016 07:31 PM

Tim I have the same issue on my Cafe. Both motors dead on until about 2800 RPM then the port lags between 100-200 RPM. It has been like this since I bought it. Changed the drives from 1.36 to 1.50 and propped accordingly, still the same lag. Bumped power on both motors, AFR's the same, went from 26 to 28 pitch bravo props, still the exact same issue. Did some prop testing and threw a set of labbed 27 pitch Hydromotives on it, couldn't plane for chit but both motors were dead nuts identical, I mean spot on through the entire RPM range. Went back to my 28 Bravos since they have worked the best, and stopped worrying about it.

A thought, have you swapped drives side to side, spinning in to see if the lag changes?

getrdunn 08-09-2016 08:26 PM


Originally Posted by donzi matt (Post 4469026)
Tim I have the same issue on my Cafe. Both motors dead on until about 2800 RPM then the port lags between 100-200 RPM. It has been like this since I bought it. Changed the drives from 1.36 to 1.50 and propped accordingly, still the same lag. Bumped power on both motors, AFR's the same, went from 26 to 28 pitch bravo props, still the exact same issue. Did some prop testing and threw a set of labbed 27 pitch Hydromotives on it, couldn't plane for chit but both motors were dead nuts identical, I mean spot on through the entire RPM range. Went back to my 28 Bravos since they have worked the best, and stopped worrying about it.

A thought, have you swapped drives side to side, spinning in to see if the lag changes?

Sounds very reasonable. Good post. Just looked back to post # 4 & 5 though???

Full Force 08-09-2016 08:44 PM

exactly, leading me to distributor, coil, and wiring to look at, floats good, airflow good, all the other things are good

Originally Posted by monster12valve (Post 4469017)
im trying to think... Everything different between the boat and the dyno... Waves... Vibrations.. Angle.. Drives... Trans


Full Force 08-09-2016 08:48 PM

It lags with all 3 sets of props I have tried, never swapped drives but when I first did engines last June they were equal, then all of the sudden they were not and have yet to be, that's one reason I dynode to rule out engine issues, that's why I am trying to look at things that change once in the boat.

I must figure it out because I know its gotta be something dumb, I am gonna try everything I can until I figure it out lol


Originally Posted by donzi matt (Post 4469026)
Tim I have the same issue on my Cafe. Both motors dead on until about 2800 RPM then the port lags between 100-200 RPM. It has been like this since I bought it. Changed the drives from 1.36 to 1.50 and propped accordingly, still the same lag. Bumped power on both motors, AFR's the same, went from 26 to 28 pitch bravo props, still the exact same issue. Did some prop testing and threw a set of labbed 27 pitch Hydromotives on it, couldn't plane for chit but both motors were dead nuts identical, I mean spot on through the entire RPM range. Went back to my 28 Bravos since they have worked the best, and stopped worrying about it.

A thought, have you swapped drives side to side, spinning in to see if the lag changes?


Full Force 08-09-2016 08:49 PM

they why would they dyno identical?


Originally Posted by getrdunn (Post 4469019)
Might come to doing a compression and leak down unless you already have. I realize their fresh engines but...


Brandonb_05 08-09-2016 09:10 PM

I don't know how your charging system is wired, but a simple check. Check all battery's and connections. Possible a alternator is causing more draw on one motor than the other. I could be way off, just a idea.


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