1996 Tournament 192 w/E-Tec 150 - Engine Questions

[Woofman]

The motor is great and I actually like it better than a four stroke on this boat. Anyway the engine has a four blade stainless Cyclone prop. Tops out at 41mph with just gas and myself fully trimmed, which is fine with me but the rpms are at the very low end recommended for the engine. Also if I am not trimmed I feel like the rpm's are too low. Has anyone tried a four blade setup? I dont know the size/pitch off the top of my head but I would assume a lower pitch may bring the rpm's up? Anyone have any ideas? Thanks

 

[DennisG01]

Can you add some "data" so we can get a better idea of what you're talking about? "At the very low end" and "I feel" are very subjective. But, generally speaking, dropping a couple inches will net you 300-ish RPM's. 3-blade vs 4-blade... meh. Kinda a personal preference - depends on what you want.

 

[Woofman]

Trimmed up I can get the rpms to almost 5000. Where I boat most days there is little trimming due to the chop so 47-4800. I will take it in after the season and see what the engine scans say but to me it sounds and feels like its lugging when trimmed down. Is the spec supposed to be when trimmed? Maybe it's just because its quieter than what I am used to?

 

[DennisG01]

"Is the spec supposed to be when trimmed?" What are you referring to here?

What is the WOT RPM range for your engine?

If you trim down too far, you're pushing a lot of boat into the water. Too much boat in the water equates to a lot of resistance/drag.

 

[Finest Kind]

First thing to do is have someone look down over your transom at the motor while the boat is up on plane and trimmed normally. If the cav plates are not visible (slightly above, at, or just below the water flow) you have your motor mounted too low. Raise it up one hole at a time until you get it to the right height.

Then, if you're still below 5500 minimum at WOT, you need to change that prop to one with a lower pitch...don't delay!
Running an Etec that cannot achieve it's recommended WOT RPM can destroy your motor.
That engine should top out at 6000 rpm with a light load, trimmed out.

Go here and do a search, there are tons of postings about WOT RPM and it's importance:
http://www.etecownersgroup.com/categories

 

[DennisG01]

We should also know if this is a new issue, or has it always been doing this (for how long)?