Trx189 with 150l motor little help please.

[cobracrazed]

Okay so I’ve got a 2018 trx189 with the 150L 4 stroke. Boat came factory with 21 pitch tempest plus. I thought all this time that I was running 6100-6200 rpms on stock tach only getting 52-53 mph wot but after installing the vesselview last week I realize I’m getting ONLY getting 5,430 rpms max with h20 water pressure 35 psi on vesselview. Motor mounted second hole from top so I could move motor up one notch and be all the way up. Boat gets out of the hole great. Prop to pad at 5” best I can measure. Trimmed all the way up zero rooster tail and looking behind boat you’d think my boat was a pontoon. I know this boat is never going to be a race boat but I just think 53 is sad and would like some opinions. Jackplate? Then play with prop? I’d think this boat would be 57-58 when right? Any input appreciated.

[CaymasMan250]

I realize your motor size but I’ve had two of the 250 4s Mercs and both never got above 5500 rpm per my vessel view. Didn’t matter what prop etc that all it would turn. I have no advice as not familiar with the 189 but though I’d let you know my RPM issues.

[cobracrazed]

I realize your motor size but I’ve had two of the 250 4s Mercs and both never got above 5500 rpm per my vessel view. Didn’t matter what prop etc that all it would turn. I have no advice as not familiar with the 189 but though I’d let you know my RPM issues.

well I be darn. Interesting. I see where folks are getting 58-5900 out of their 189trx but that has the newer 150 pro xs motor. Thanks for sharing. I’d think if I could get the motor out of the water some, I’d think it would help. She’s plowing pretty bad trimmed out.

[CaymasMan250]

My 21 trxs boats did the same because they are heavy and just can’t get out of the water, I added two degree wedges and made lots of difference. There is a man on here I helped with that same issue on his boat and it woke up big time.

[Jimmy3]

For what it's worth my dealer put my 2018 trx with the 150 optimax in the forth hole down. Boat still shoots out of the hole but has a ton of slip on the top end. Analog tach reads that I'm getting 5800 rpms but I'm only getting 51 mph most days and 6400 rpms for 52 MPH on good days.

The boat's in the shop getting a 6" manual plate put on right now. We'll see how it goes in a couple weeks. So far I love the fishability of the boat and handling on the low end but very disappointed with the top end results so far. Based on what I read it should be a mid to upper 50's boat with a 150 on it.

[itsahog]

If I’m not mistaken the max RPM for the 150 L 4 stroke is 5800 RPM, is this correct? I have a good friend who has the same year/boat as you, same motor with the tempest prop, almost certain its also a 21 pitch. He has two power poles, and he can get about 54 miles an hour out of his boat. He has a jack plate, and I helped him raise his motor to 3 inches PTP, he does not have a water gauge so that as high as we dared bring it. I’m guessing with out the power poles he could probably get maybe 56 mph. You can raise your motor and increase your RPMs and probably your speed a bit, just make sure you maintain water pressure. My prior boat was a Triton TR 186 with a 150 hp OptiMax, I had my motor 3 inches PTP and got 59.9 mph GPS. That boat was quite a bit lighter than a 189. If you are 5 inches below pad, you need to raise your motor, in my opinion pretty much everything will improve, handling and the speed. I don’t think you will reach 60 miles an hour although I could be wrong.

[Jimmy3]

I know the rpm limit is 5850 on the optimax, at least that's what my dealer said. I think he said it was 6200 for a 4 stroke but I could be mistaken.

[itsahog]

I know the rpm limit is 5850 on the optimax, at least that's what my dealer said. I think he said it was 6200 for a 4 stroke but I could be mistaken.

I’m almost certain 6200 is for the Pro XS motors only, I think for the 150 4 stroke it’s 5800 RPM, the Opti was 5850.

It gets confusing, from what I understand the Pro XS 4 strokes have a max RPM of 6200, the non-Pro XS 4 strokes have a max RPM of 5800, and your correct my old Optimax had a maximum of 5850.

[cobracrazed]

I’m almost certain 6200 is for the Pro XS motors only, I think for the 150 4 stroke it’s 5800 RPM, the Opti was 5850.

It gets confusing, from what I understand the Pro XS 4 strokes have a max RPM of 6200, the non-Pro XS 4 strokes have a max RPM of 5800, and your correct my old Optimax had a maximum of 5850.

sure enough 5800 max per my book. With being only one hole left that may get me out of the water another inch or so? I may just look into a 6” jack plate (max on my boat) and go from there. I’ve got no idea how else to get that motor from plowing so deep and with me having 35 psi water pressure I’d think I could come way up. I will have to check and see what minimum water pressure is on these motors. Thought it was somewhere around 12-15.?

[cobracrazed]

For what it's worth my dealer put my 2018 trx with the 150 optimax in the forth hole down. Boat still shoots out of the hole but has a ton of slip on the top end. Analog tach reads that I'm getting 5800 rpms but I'm only getting 51 mph most days and 6400 rpms for 52 MPH on good days.

The boat's in the shop getting a 6" manual plate put on right now. We'll see how it goes in a couple weeks. So far I love the fishability of the boat and handling on the low end but very disappointed with the top end results so far. Based on what I read it should be a mid to upper 50's boat with a 150 on it.

.

Have them check what your max rpms has been at the dealer man. Those gauges SUCK. I installed vesselview (I’d recommend it for $200!) and you can get digital accurate readouts right on your phone for all important information but most importantly rpm’s and water pressure!. My boat was showing me at 6200 rpms. Wrong! Got vesselview and it’s turning right at 800 less than that at 5,430 max. I’m not sure how anybody could actually get the most out of their boat/motor without having a water pressure gauge and ACCURATE rpm gauge. I’m telling you, don’t trust those stock rpm gauges. Seriously though bud look into mercury vesselview. I love it. And it’s cheap!

[Jimmy3]

I just found out about the mobile vessel view a few days ago, it's definitely something I'm looking into. I'll probably get it after I get my boat back so I can adjust my jack plate without worrying about being to high.

[cobracrazed]

I just found out about the mobile vessel view a few days ago, it's definitely something I'm looking into. I'll probably get it after I get my boat back so I can adjust my jack plate without worrying about being to high.

Exactly.

[TritonTRXV8]

I’m almost certain 6200 is for the Pro XS motors only, I think for the 150 4 stroke it’s 5800 RPM, the Opti was 5850.

It gets confusing, from what I understand the Pro XS 4 strokes have a max RPM of 6200, the non-Pro XS 4 strokes have a max RPM of 5800, and your correct my old Optimax had a maximum of 5850.

This is correct. Only real accurate way of knowing is from either a smartcraft gauge or the vessel view. Never messed with the vesselview so i cant vouch for their accuracy. I would say to get the most out of your setup a 6” jack plate is the best bet. Its not just raising the motor its the setback that improves performance as well putting the prop in cleaner water for better bite.

[cobracrazed]

This is correct. Only real accurate way of knowing is from either a smartcraft gauge or the vessel view. Never messed with the vesselview so i cant vouch for their accuracy. I would say to get the most out of your setup a 6” jack plate is the best bet. Its not just raising the motor its the setback that improves performance as well putting the prop in cleaner water for better bite.

thanks for the reply ��. It is actually at the shop now having a warranty part replaced (trim pump issue) and they are putting a 6” manual plate on it while there. Do you think that getting the motor up some will also help me get more rpms/speed? I know she will never be a speed boat. A small improvement would be fine by me.

[jjtriton]

thanks for the reply ��. It is actually at the shop now having a warranty part replaced (trim pump issue) and they are putting a 6” manual plate on it while there. Do you think that getting the motor up some will also help me get more rpms/speed? I know she will never be a speed boat. A small improvement would be fine by me.

The jack plate will definitely allow you to pick up a few more rpms and a few mph. The engine needs to put mounted in the third hole. Raise the engine until it has a tendency to cavitate coming out of the hole, the drop it until it hooks back up. On the standard 150 4/stroke you will probably need a 21 Tempest.

[itsahog]

The jack plate will definitely allow you to pick up a few more rpms and a few mph. The engine needs to put mounted in the third hole. Raise the engine until it has a tendency to cavitate coming out of the hole, the drop it until it hooks back up. On the standard 150 4/stroke you will probably need a 21 Tempest.

I have a buddy with the exact same set up, we have his prop to pad at 3 inches. If you have somebody that will let you try a 22 pitch I think it would be worth trying. he’s getting 55 at best with two people in the boat, with his 21 pitch and a JP. It would be interesting to see how a 22 pitch would work, you may give up some RPMs but actually gain speed, I’m not sure. All of his vent holes are plugged with solid plugs if that helps.