How to upgrade 4Stroke 50HP to 60HP

[Jdeagro]

Re: How to upgrade 4Stroke 50HP to 60HP

Jordan;<br /><br />The extra Hp is not going to help get you on plane any faster. The extra HP and torque do not come in until the higher RPM range.<br /><br />The stern drops when you accelerate because the path of least resistance for the bow is into the air not the water. What you need to do is keep the stern from dropping (creating the hole) so that the thrust is used to move forward not climb up out of a hole. The most effective thing you can do is to add Trim Tabs (Smart Tabs). We guaranty the performance results - check the mega mall listing for the guaranty.

 

[jordan2]

Re: How to upgrade 4Stroke 50HP to 60HP

As I said, I was able to get up on a plane much easier with he 10 1/2 pitch prop but gas mileage suffered as a result. I maxed out on RPM (5500) so i had to be constantly aware of that and train myself not to push it wide open. Top end speed? I didn't notice much difference. The answer for me is to use the 10 1/2 pitch prop until I get to camp and then to change to my 12 SS prop. I will also look into the Trim Tabs.

 

[jordan2]

Re: How to upgrade 4Stroke 50HP to 60HP

I asked some of the guys in my fishing circle about trim tabs. We all have flat bottom boats....Carolina Skiffs. <br /><br />Here's what one of them said, "Usually a flat bottom boat does not need them-the whole flat bottom acts as a trim tab."<br /><br />Would appreciate any feedback.

 

[Nos4r2]

Re: How to upgrade 4Stroke 50HP to 60HP

what top speed are/were you getting?

 

[longshanks]

Re: How to upgrade 4Stroke 50HP to 60HP

I'm reading this post with interest.

Has anybody successfully replaced a 50 ECM with a 60 ECM?

The dealers will sell me the part, no problem. All other parts between the 50 and 60 look the same. My motor has about 35 hours on it, but with the props I've tried, I've not been able to get RPMs above 5200 or so, @ WoT. Not close enough to the real power band for this motor. I'm thinking that with 17% more power, same weight, all those props I spent good $ on, might suddenly become useful? If I avoid buying more props, $1000 for a new computer doesn't seem that much.

Warranty on my motor comes due next spring. My options are to either try and sell/replace the motor with something larger, or, put a 60HP computer in my nearly-new motor.

Anybody?

 

[Silvertip]

Re: How to upgrade 4Stroke 50HP to 60HP

In most cases you will not notice the 10 HP difference which makes the $800 to $1000 expense sort of a waste. Working with engine height (AV plate even with or above the keel) and trim settings should be done first. Then think about props. Ventilating a prop is an effective "hole shot" modification for a two stroke but it is not as effective on a four stroke. Remember, a two stroke fires all cylinders on every rev while a four stroke only fires half its cylinders on each stroke.

 

[kergoat]

Re: How to upgrade 4Stroke 50HP to 60HP

i made it
swapp ecm 50 efi to 60 efi
remove air restrictor in air admission

the big difference is in nervosity accelerate very fast, in comparison of my 50 efi ! more top speed (+3knt) propeller
on 50 efi :
blackmax 12 " : 6000tr/mn max wot 30 knt
on 60 efi
blackmax 13" : overrange 6250 33knt
blackmax 14" : wot : 6200 33 knt
vengeance mercury ss 14 wot : 6000 perfect 34/35 knt

 

[Silvertip]

Re: How to upgrade 4Stroke 50HP to 60HP

Venting or drilling a prop has very little effect on a four stroke motor so I wouldn't risk screwing up a good prop with that technique. I would also not expect spending a grand on a computer getting you any significant performance increase. Besides -- you are complaining about fuel economy now. You can't get blood out of a turnip nor can you get better economy by going to a 60 from a 50. The 60 will burn 6 gallons/hour vs 5 gallons/hour on the 50 at wide open throttle. When it comes to a boat, you consider acceptable performance first and you must accept whatever economy that level of performance provides.

 

[MercFan]

Re: How to upgrade 4Stroke 50HP to 60HP

I was also going to advice to simply vent the prop. It simply aerates the water around the prop at low speeds. So you get higher rpm for the same speed. Until the water flows over the holes so fast that they don't leak exhaust anymore. Then the prop behaves like a normal unvented prop. But if your engine has a very flat torque curve, you won't score much by doing it.

 

[kergoat]

Re: How to upgrade 4Stroke 50HP to 60HP

i m french so metrics :

smartcraftinfo speed : nautics cons liter by hour

stingray rib 5.20 (500kg) 2 man 70 l fuel

60 EFI:

3500 14 knt 7.6 l/h
4000 19 knt 9.5 l/h
4500 22 knt 11.6l/h
5000 26 knt 13.8l/h
???? 27 knt 14.4l/h
5500 30 knt 17 l/h
6000 34 knt 20.8 l/h


50 EFI

3500 14 knt 7.6 l/h
4000 19 knt 9.5 l/h
4500 22 knt 11.3l/h
5000 25.6 knt 13.5l/h
5500 28.7 knt 16.2 l/h
6000 31.6 knt 20 l/h


fot me same consumption