So after taking the boat to the dealer today and recording the results on the computer the Merc gods say I need to try a 27 pitch Max5ST prop
So after taking the boat to the dealer today and recording the results on the computer the Merc gods say I need to try a 27 pitch Max5ST prop
I would think the 26 would be a better starting point. JMHO.
These Max 5’s runs about 5% slip.
Did they have to change the throttle setup to achieve 100% demand?
If NO, 27P is still going to be too steep.
If YES, what percentage was it achieving?
Dual Mercury Master Technician- for Mercury Outboards, Mercruiser and Mercury Racing at European Marine in Greenville, SC.
Still consider myself a "Marine Apprentice" after 47 years (learn something new every day).
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Throttle was set to 100%. Myself with the tech on board with computer recorded a run and sent it to Merc tech and they said to try a 27 Max5ST I think it will turn maybe 5600 with it but don't have the prop yet to try...Going to try a 27 Pro Max tomorrow
You need to be around 6200 rpms
I Haven’t seen it mentioned here and not sure what gearcase OP had on the previous 250 but he will need to run this gearcase with the propsahft at least 1-1/2” above the pad to get this boat to perform to it’s potential and achieve the correct RPMs. With a Max5 prop probably 1-3/4” to 2” above.
‘17 Bullet 21 SDC ‘20 Merc 300R 1.60 SM 1E081012
Have no experience with a Bullet..... I do know these redesigned LU are way different than there predecessor and to achieve full potential of the V8 its going to take some work. I'm running the 250R over 1" higher than same boat with a 300XS 2 stroke.Originally Posted by rocketmanjp
Happily on my rig I can turn the same props on this 250R that I used with 300XS but it took some work and a lot of advice from Geoff Erickson, Jay McDaniel and Tim Powell-- who is also well versed on Bullits. I know he is busy at Fastbass Marine but I bet he could give you some set up tips.
Soon to be 300R owner. If you look at the throttle blade turn the key on push the throttle to WOT does the throttle blade not move because the engine is not running?
Ran the same 27 pitch Pro Max prop that I ran on the 250XS and could only turn it 5800 rpm and 82 mph I have a hydraulic jackplate so raising the engine is easy. Tried inch and a half above pad and it ran slower.
ETC (Electronic Throttle Control) is PCM controlled, based on Operator's Demand- Engine Load and other parameters, and the Available Power threshold the PCM is permitting for the given conditions.
To tell accurately- must be able to view G3-2019 CDS Data parameters (Demand, Demand Linear and Demand Linear (w/Guardian)).
Dual Mercury Master Technician- for Mercury Outboards, Mercruiser and Mercury Racing at European Marine in Greenville, SC.
Still consider myself a "Marine Apprentice" after 47 years (learn something new every day).
Mercury Parts, Mercury Outboards, Smartcraft & Accessories, Injector Service, TDR Reeds- BBC Sponsor
On the Bullets some have said they cannot get away with running the same props they ran on XS engines prior to getting the R. On the Allison's that is not the case. On both boats we all agree the motor runs much higher than with the XS. Many of the Bullet guys have not liked the Promax on the R. With the higher motor heights and the smaller diameter they feel it is an issue. On the Allison we haven't seen that. Not that this helps you but on the Allison's the prop is running an 1" or more higher, still hooking up, and takes the boat right into the 100's with the Promax. You may want to reach out to some of the Bullet guys on this forum or FB for some prop suggestions. Steve Bishop in Florida has done a lot of Bullet 300R testing.
In 3 days of testing on two different boats we could not get the 1.6 300R to run with the 1.75 300R. On my boat I couldn't even get the 1.6 case on my 300R to out run the 300XS 1.62 I had on before the R with the same props. Very confusing results as we did the same test on my boat with a 300XS 1.62 and 1.75 and the results favored the 1.62 case on top and 1.75 for acceleration as logic would have one think. The 1.75 300R on my boat out accelerated and had a bigger topend vs. the 1.60 300R. All testing with the same motor, just swapped cases. Many tests were back to back.
The goal of all the testing was to re-do this video below with the 300R. We ended up doing so much trouble shooting that we never got around to it. That was 3 straight days of testing from sun up to sun down with over 20 props available. It was a perplexing time.
Allison XB21 2+2
Mercury 300R
The Pro Max prop was the one I ran on the 250xs torquemaster 1:62 gears. It will be for sale soon . Just thought I'd see if it would get close to 6200
Considering a 300 r on mine anyone have advice I have a 300xs with 160 hrs on it.....
Ron Fears
Stroker/300XS
1E003823
If you don’t have a DBR kit on your current 300XS the R will be more powerful. Is it worth the cost to upgrade? That is a personal decision. I would get 1.75’s.
Here is the best comparison I could make. For a number of reasons I couldn’t do back to back testing but despite that the results are consistent with day to day performance.
Allison XB21 2+2
Mercury 300R
^^^ what Geoff said ^^^
I would concur- 1.75 gear ratio would be best suited for your application.
Dual Mercury Master Technician- for Mercury Outboards, Mercruiser and Mercury Racing at European Marine in Greenville, SC.
Still consider myself a "Marine Apprentice" after 47 years (learn something new every day).
Mercury Parts, Mercury Outboards, Smartcraft & Accessories, Injector Service, TDR Reeds- BBC Sponsor
How can I get a 1.75 case? Mercury doesn't seem to care that I'm not happy with the 1.6o...They say the 1.60 case was designed for triple digit boats...I tried a 26 Pro Max and could only turn it 6000rpm and 83.4 mph
Have the folks at Performance not been able to provide you with any assistance on that? Normally that would be the "1st stop".
While you'd want to get clearance from Merc before changing the gear ratio I know I've seen some 1.75's out there.
Dual Mercury Master Technician- for Mercury Outboards, Mercruiser and Mercury Racing at European Marine in Greenville, SC.
Still consider myself a "Marine Apprentice" after 47 years (learn something new every day).
Mercury Parts, Mercury Outboards, Smartcraft & Accessories, Injector Service, TDR Reeds- BBC Sponsor
Don,
The folks at Performance have been great to work with. We are waiting now on a 27 Max5st to try but with the tests I've done with the Pro Max props I'm sure it wont turn it either
A Max 5 prop is a lot tighter then a pro max.
Example I have a 30 pro max I can spin to limiter 6250. and a 29 Max 5 only to 6000
The boat is a Stroker and motor is 250R with 1.75 gears. Boat loaded, 3/4 tank gas, 2 people over 400lb, 2 power poles, loaded to fish
Both prop run just a shade over 90.
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