prop for 2510 xl with f250

[piano player]

now that my rod racks are "temporarily" installed i have a power question.

yamaha has a performance posting on my boat which indicates that the speed should top out just over 40 mph. i am lucky to get 35 wot (6000) i generally run 4400 @ 27-28 mph.

the yamaha bulletin uses a saltwater II prop in there test and i have the standard black painted prop.

the dealer mechanic says that my prop is fine but in order for an f250 to perform better than an f225 i should try some hi test fuel. something about the variable timing kicking in and 10% ethanol fuel.

what are your thoughts? i will get a new prop if it will help. and or i will find an octane booster if that is recommended. high test fuel isn't available @ my marina.

my sales person is checking with parker and will get back to me.

i am concerned about trolling speed.

 

[Megabyte]

i am concerned about trolling speed.

I switched from the Yamaha black painted stainless prop to a Mirage Plus and realized better performance all around.
I'm still a bit overpropped, but I can live with that.

Trolling speed is an issue however. The prop bites so well that I run between 3.5 and 4 kts at 800 rpm which is a little too fast for Rockfish...
But, I'll be ready when the Spaniards arrive!

Everything about boating is a compromise. You just have to decide if a little more top-end speed is worth the trade-off.

 

[DaleH]

the dealer mechanic says that my prop is fine but in order for an f250 to perform better than an f225 i should try some hi test fuel. something about the variable timing kicking in and 10% ethanol fuel.

what are your thoughts?

It's true ... the F250 only develops that horsepower with 89 or better octane fuel. Regardless of whether or not you can get that fuel, it is always best to MATCH the prop to the maximum RPM band of the motor, trying to turn about 200 RPMs off MAX rating, with 2/3rds fuel, 2 people and typical gear on board.

The absolute WORST thing for an OB motor is to be over-propped.

 

[piano player]

thanks for the advice.

since my engine will hit 6000 with a full tank and two on board it sounds as if more bite from the prop will be good for top end performance. however, 4 miles an hour trolling speed would not work well all the time. though my motor will idle @ 500-600 rpm.

the octane @ my marina is 89. so that is propably not the biggest issue.

i will let you know what answer i get from parker.

thanks

 

[piano player]

my sales person is still reviewing the speed issues with my boat. parker has indicated that i should get more speed. (40 mph @ wot) the tech staff @ the dealer has suggested that someone from the shop should test the boat. i think that is a good idea since i am now down to about 33mph! things must be growing quickly on the hull!

one interesting thought was that i could repower with a new 350hp yamaha (when available) but this would require some bolstering of the bracket etc. and would likely require sending the boat back the factory.

also, trolling might be faster than even a big fish can swim!

i'll let you know when i know more

 

[grouperjim]

Hey guys:

I am not a troller so give some schooling on troll speed.

If your troll speed is a little high due to prop selection, why can't you use your tabs to adjust your min speed?

jim

 

[DaleH]

the dealer mechanic says that my prop is fine but in order for an f250 to perform better than an f225 i should try some hi test fuel. something about the variable timing kicking in and 10% ethanol fuel.

True on BOTH counts~, or should I say "all 3"!

#1 - The F250 allegedly puts out ~mid 230s on 87 octance and needs 91 (I believe) to advance the camming so she puts out 250hp (+/- the 10%) to meet the standard for horsepower ratings.

#2 - E10 or ethanol formulated fuel lacks the 'power' MTBE fuel had and performance can be 5-10% less than before. Remember, we have NO WAY of knowing whether we got 10% or MORE ethanol laden fuel and the more there is of the alcohol - the less powerful a mix it is.

#3 - Don't ever believe any boat test, they are a 'gauge' only, some are close, but I've never seen anyone beat any of the performance speeds or efficiencies posted (regardless of boat or motor brand(s) ... less when being trailered on the highway behind your truck

!

Adding to that, you have more gear, your might have bottom paint, your OB may be positioned too low, not trimmed out until blowout and then in a touch ... etc.

 

[John_Madison CT]

FWIW, I can get in the upper 30's WOT on my Parker 2520DV (21 degree deadrise) with a light load, running a Yamaha 250hp Ox66 on a bracket.

I suppose it's possible to hit 40mph with your boat, especially since it has a shallower deadrise.

 

[rangerdog]

On Trolling. My boat is propped just right out of the factory, I think. In any case I won't change the prop. If you have an aggressive prop there's only so much you can do about trolling. 1) Fully deploy tabs (depending on tide and direction of troll) 2) Trim the motor waaaaay up. 3) Deploy a five gallon bucket(s) drift "socks".

95% of my fishing is trolling, if I couldnt get to a "crawl" with my motor, I couldn't properly troll. Wind, current, and whim of the fish demand ultimate speed control.

 

[tommyr904]

i have been playing with props on my boat the lst few weeks.i have tried several yamha props and the best i can get out of my 2520 with a f250 is 38 mph wot @5300rpm the rpm's should be a little higher but @ 4700 rpm i'm going 30 mph burning 14 1/2 gph.that is the best speed to gph i have found so far.thats with a 151/2 x 17 salt water series 2 prop.i think my next plan of attack is take that prop to a prop shop here in town and see if they can take just a little out to get the next few rpm's i need.

 

[piano player]

i've been away and havent been online.

thanks for all of the thoughts. bottom paint detracts from speed, a thought that came back from the dealer rep. i've been boating for a lot of years and never really thought about that. all of my previous boats were 40mph plus boats and i never go that fast. my dealer sells gradys and parkers and this is my first parker.

bottom paint, prop, gas with 10% ethanol, 89 octane (not 91) gear, a fat man and his wife! a full tank of gas, all probably contribute to my boat getting less than best speed. truth is i don't really care about the extra speed and i certainly wouldn't want to increase trolling speed. though we mostly drift fish. then again i might try a saltwater ii prop some day.

interestingly, this morning was cool and i think we were moving with more power than usual.

we really like the layout of this boat compared to the gradys we've owned.

my understanding on the 350 is that people will not be repowering with it because of the added weight. even though twin 150s weigh more than one 350 the distribution is different. that is what the dealer said came from parker. in the same breath they said the bracket could be bolstered and some holes for more bolts could be added. who's to say?

we were out fishing this morning and caught our usual 30 or so fish. we are catch and release individuals. this parker seems to collect fish in its shadow and it drifts slower than the gradys we've owned. that is quite amazing. and since we don't want to break what doesnt seem to be broken, we will likely leave everything as is and just fish.

good fishing

piano player