I've got a 2017 90 HO ETEC tiller. I've got it on a 2017 Larson FX1850TL. The dry weight on these boats are 2100 lbs. I've got a 15 pitch Turbo prop on it. I've tried a couple others. My issue is that I can't get over 5100 RPMs no matter how much I trim it. I trim it just to the point where the nose of the boat starts to bounce, and then I lower it just a touch. I know I'm missing out on RPMs and speed. Nobody around here knows what prop to put on it. Any help?
08-22-2017 07:16 - edited 08-22-2017 07:17
If your engine does not go over 5100 rpm after trying different props or trimming the engine, the first thing to do is to check the accuracy of the tachometer. A dealer with a laptop can quickly compare actual engine rpm with the tachometer readings.
What is the complete model number on your engine as printed on the serial number tag?
What speed are you seeing with the 15" Turbo prop and is it a GPS speed reading or from a speedometer?
4 weeks ago - last edited 4 weeks ago
Seems underpowered to me. My bay boat weights 1850lbs dry and when we test drove it with the 115 Etec, it was sluggish. Opted for the 150ho. Cruising at 30mph and getting 4-5mpg is nice.
Edit: i just looked at the website for Larson boats. The tiller model FX1850 is max rated to 90hp, but the dual console FX1850 is max rated to 200hp and only weight 200lbs more. Same length, same beam (i.e. same hull). Tiller operation must limit the hp rating since they are the same hull.
3 weeks ago
that model has the 2.27 gear ratio lower unit. From the numbers you stated, the tachometer could be inaccurate by a few hundred rpm. Have your dealer check the tach accuracy by using the diagnostic software and a laptop and comparing the readings.
Also check if the motor is mounted too low on the boat. The anti-ventilation plate should be visible skimming across the top of the water at speed, not underwater.