Simon Performance Flash - 2017 175TXW w/75HP Fourstroke

[msupc]

I purchased a 2017 Tracker 175TXW w/ 75HP Mercury Fourstroke in November of 2019. At the time of purchase, it had a 18" pitch Vengeance prop. The boat would make 39-40mph @ roughly 5400 RPM. I was looking to increase speed and performance and learned, through searching the forums, that the intake restricting plate could be removed to add power (essentially turning it into a 90hp engine). I removed the plate and took the boat out, and under full-throttle the Mercury Monitor would kill power once on plane. I was able to achieve 40mph @ 5250 RPM with the 18" pitch prop and restricting ring removed, but I could not go full throttle.

I thought that the factor tachometer may be off, and I was running into the limiter, so I purchased a 21" pitch Spitfire X7 prop and put it on. I was then able to achieve 39-40 mph, and the engine would only spin up to 4700 rpm roughly. Again, once under full throttle, the Mercury Monitor would kill power. I later deduced this to the engine running lean?

I then decided to send my ECM off to be flashed by Simon Performance hoping that the increased power would spin the 21" prop faster and increase speed. I received the ECM back this week and took the boat out. Now with the 21" Spitfire X7 prop I could only spin it to 5200 rpm @ 41mph. I decided to swap the 18" Vengeance prop back on, and the RPM increased to 5800-6000 (depending on trim) and can see 42 MAYBE 43 MPH.

Does this sound right to you all? I have seen all of ship's and other's posts regarding flashing their 75 Optimax's to 115, and they are spinning 24" laser 2's and seeing 48-50 MPH.

This is all with only me in the boat (195lb), half a tank of fuel, and rods/reels and tackle. Also, the engine is mounted in the second hole from the top.

[Jraywheat]

Sounds like you are maxxing out on the RPM's (6000). Not much else you can do. I would think you should be seeing more speed than that. Is that GPS speed or from the speedometer?

[msupc]

Yes, that is GPS speed. I was thinking it would go faster than that as well seeing as how the claimed new HP by Simon Perf is 120hp. A jump in 50 HP for only 2-3 mph?

Also, I was wondering if raising the motor might help? It’s in the second from top hole now.

[bassfisher444]

What does Simon performance charge to fash the ECM? I have a 90 HP on my 175TXW and I may get that done depending on how much speed I can get out of it now.

[msupc]

I believe for the flash it was $675. You pay shipping both ways. It REALLY woke my 75hp fourstroke up - holeshot and mid range improved significantly. Just thought top end would improve more.

[fishon396]

I have the same motor on a rt 178 and get about the same stock numbers as you with a x7 Mercury spitfire 17 p 4 blade prop. I think max rpm for the 75hp is 5500 and for the 90 and 115 is 6000 so I wonder which would apply for the flashed motor. Something does not sound right with the top speed it could be the prop or motor height but the stock 75hp ran good at that height so maybe it is the prop. I would maybe check and see what prop the Mercury 4 stroke 90 and 115 motors have on them.

[bshort]

Those numbers seem accurate. I get about 42 with a 17P X7.

[alanhore]

I have a 2013 Crestliner VT17 with a Merc 75 4 stroke. I had my ecu tuned by Simons. My boat with me and a half tank of gas will hit 50 mph gps before the porpoise starts to get started. I have ran a 19 pitch Apollo xhs, a 19 pitch x7 spitfire and a 20 pitch LazerII. they all behave a bit different but over all the 19 spitfire is the best over. I think I could turn the 20 Lazer to redline (6000) but cant get past the porpoise. The one time I let it bounce I got about 53 mph out of it at about 5800, but it was not fun. The Lazer I got used and looks like it has been messsed with. It sounds like your set up just is not working very well. I dont know about the gear box ratio difference between our two motors, But If is close to mine aint no way you are going to turn a 24 pitch prop anywhere near redline. jmho.

[alanhore]

Flashed max rpm is set at about 6300 I believe. Also these motors run a different gear ratio depending on factory hp rating.

I have the same motor on a rt 178 and get about the same stock numbers as you with a x7 Mercury spitfire 17 p 4 blade prop. I think max rpm for the 75hp is 5500 and for the 90 and 115 is 6000 so I wonder which would apply for the flashed motor. Something does not sound right with the top speed it could be the prop or motor height but the stock 75hp ran good at that height so maybe it is the prop. I would maybe check and see what prop the Mercury 4 stroke 90 and 115 motors have on them.

[msupc]

Those numbers seem accurate. I get about 42 with a 17P X7.

Was yours tuned by Simon?

[msupc]

I have the same motor on a rt 178 and get about the same stock numbers as you with a x7 Mercury spitfire 17 p 4 blade prop. I think max rpm for the 75hp is 5500 and for the 90 and 115 is 6000 so I wonder which would apply for the flashed motor. Something does not sound right with the top speed it could be the prop or motor height but the stock 75hp ran good at that height so maybe it is the prop. I would maybe check and see what prop the Mercury 4 stroke 90 and 115 motors have on them.

That is a good idea. I will try to find what prop the 90 and 115 come with. I took her out again yesterday. 5500 RPM and 42 MPH on the nose. Any more trim and prop slip would increase, the boat would slow down, and the exhaust would get substantially louder.

I wonder if moving the motor up one hole would help?

[msupc]

I have a 2013 Crestliner VT17 with a Merc 75 4 stroke. I had my ecu tuned by Simons. My boat with me and a half tank of gas will hit 50 mph gps before the porpoise starts to get started. I have ran a 19 pitch Apollo xhs, a 19 pitch x7 spitfire and a 20 pitch LazerII. they all behave a bit different but over all the 19 spitfire is the best over. I think I could turn the 20 Lazer to redline (6000) but cant get past the porpoise. The one time I let it bounce I got about 53 mph out of it at about 5800, but it was not fun. The Lazer I got used and looks like it has been messsed with. It sounds like your set up just is not working very well. I dont know about the gear box ratio difference between our two motors, But If is close to mine aint no way you are going to turn a 24 pitch prop anywhere near redline. jmho.

This is what I was expecting. I am thinking I may need to raise the engine one hole, see how it performs there, and consider going up in pitch to a 19.

When I had her out yesterday it went 42MPH at 5500 RPM. It was really balanced at that trim level, but any more trim and speed would decrease, RPMs rise (could take it up to 6,200 or so), and exhaust gets much louder.

[bshort]

Was yours tuned by Simon?

Yes. Outboard is in the 3rd hole too.

[msupc]

Yes. Outboard is in the 3rd hole too.

Interesting. I wonder why the performance discrepancy between the 75-115 Optimax flash and the 75-115 Fourstroke flash? Wilds and others were getting 50+MPH and turning 24" props, while it seems we are merely capable of spinning 18"-19" props and MAYBE mid-40's. Our lower unit has a gear ratio of 2.07:1.

I believe I will raise the motor and see what happens. What difference did you experience when raising the motor?

[bshort]

Interesting. I wonder why the performance discrepancy between the 75-115 Optimax flash and the 75-115 Fourstroke flash? Wilds and others were getting 50+MPH and turning 24" props, while it seems we are merely capable of spinning 18"-19" props and MAYBE mid-40's. Our lower unit has a gear ratio of 2.07:1.

I believe I will raise the motor and see what happens. What difference did you experience when raising the motor?

I did them both at the same time, so I have nothing to offer. The flash got me 5-6 mph. The boat is loaded down, always full fuel and always with two people. To me, the tune smoothed everything out.

[msupc]

Well I raised the motor last night to the third hole from the top. My plan is to get out this weekend to see how she performs. Stand by!

Second Hole Down:

Second Hole Down (4).JPG


Third Hole Down:
Third Hole Down (3).JPG

[Judson1]

I have the older V176 mag but had mine done in 2015 and with the different prop I saw about a 6 mph increase.

[stephensondl4]

So looking at your picture are you not concerned with your water intake and motor getting enough water to cool it and not destroy the gear box from over heating?

[msupc]

So looking at your picture are you not concerned with your water intake and motor getting enough water to cool it and not destroy the gear box from over heating?

That is a legitimate point, and I am planning on keeping an eye on the water output as I am testing. My initial thought is that such a minute adjustment shouldn’t raise the intake beyond a functional state. I believe that the water intake cools the engine and not the gearbox, or is that wrong? Either way, other owners of 175TXW have done this without problem. Also, I have an extra battery in the back (weighing the rear down more) and the heavier 75HP engine. We will see!

[bshort]

That is a legitimate point, and I am planning on keeping an eye on the water output as I am testing. My initial thought is that such a minute adjustment shouldn’t raise the intake beyond a functional state. I believe that the water intake cools the engine and not the gearbox, or is that wrong? Either way, other owners of 175TXW have done this without problem. Also, I have an extra battery in the back (weighing the rear down more) and the heavier 75HP engine. We will see!

It's 3/4" difference......I'm set up this way and have more than enough water pressure.