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View Full Version : 39 w/trip Yami 350's performance



tolock1
07-03-2011, 08:53 PM
Here are the numbers I recorded with the new props (19's outside. 21 center. 3 blade yami props);

Rpm MPG gph mph
3600 .9 30.2 28.2
4000 1.0 34.4 34.7
4500 .9 49.5 45.5
4700 .9 51.7 47.5
5000 .8/.9 59.0 49.7
5500 .7 75.4 54.5
6000 .6 90.3 58.7

The boat is bottom painted and had about 350 gallons of fuel in it. It did top out around 6100/6200 rpms. The center emgine was about 5700 while the outside engines were around 6100 until I trimmed it way up to equal out.

I was running 21's outside, 23 center and the boat seemed to run better with the new ones, but may have lost a little in top end.

Still having some issues with the bow rise. Is the only solution to go to 4 blades? What will this do to economy/speed?

Thanks,
Tom

JoeyM
07-06-2011, 04:17 PM
Hey Tom,

what prompted you to try new props? what's the bow rise issue?

tolock1
07-07-2011, 11:43 AM
Yes, at low rpm's I was having trouble seeing over the bow. The numbers have not really changed on RPM,s.

JoeyM
07-07-2011, 02:44 PM
yeah, no kidding. with our boat, i dont think anybody can drive the boat but me (i am 6'3"). nobody can see anything at a lot of speeds. and even when i sit on the seat, my visibility isnt great. i have to stand and drive. i think the boat was built for heath, ha!

your numbers look pretty good though. i'm burning more fuel (understandable, i guess). i'm most often at 0.7 mpg at 40-45 mph.