21 SS Extreme questions if you don't mind

[bassdogg]

Hi all, have some more questions if you don't mind.

225 Johnson HO, Paralift jackplate ( I hate this thing, lol ), 4 blade 25P Renegade ( switched out a 26P Raker ), 3-1/2" below pad running 60 solo. (Tach and water pressure gauges not working)
Should I be seeing more? Hole shot is better, no chine at all. I can trim out more than half my gauge, which I don't feel is right.

Where is everyone mounting their transom transducer?

Thanks guys!
Suggestions are greatly appreciated

[javelin90]

With that motor and boat you should see 70-73 mph. First you need to replace tachometer and water pressure gauges. Second check compression. Third check prop to pad motor height. Good reference point to start would be 3" . Then adjust up and using rpm and water pressure as an aid. Fourth what type brand and model GPS unit?
Before you do anything replace rpm and water pressure gauges then report back. You do not want to overheat or over rev the motor.
Has boat been sitting long before use?

[bassdogg]

GPS is a Lowrance unit. Prop to pad is 3-1/2", which from my research seems to be the sweet spot for these boats, but I will try 3.
Yes, Tach and water pressure need to be replaced. It's a pia getting to them with the dash. Is there a way to remove the dash so I can get to everything?
I'll buy a compression tester this week and check it when I can.

Thanks

[javelin90]

Not easy to replace gauges. I found on my 201 i has small flexible wrenches to loosen the nut from the gauges. From what I have read not easy to remove panel.

[bassdogg]

Ok, did a compression test
Two cylinders on 80, the rest right around 90.
I haven't checked anywhere to see if those numbers are good or bad.

[bassdogg]

I should mention that the test was done on a cold engine

[tdt91]

OP,
What you are looking for is all cylinders within 10% of each other. Yours are not so you may have an issue there or you just need to do a cleaning, it's called a DeCarb. This will clean the carbon up and free the rings up. My guess is this why you are not within 10% on all.

Next, your OMC trim gauge on that rig your needle will show all the way up when full out running so it sounds to me like you are not trimming enough. Get your gauges replaced so you can watch your pressure. You should be able to trim it as much as it will go while at WOT. Your rooster tail should not really go much higher than the top of the motor. If it does you are not deep enough, probably. You need to know your RPMs and water pressure so put it in the garage and get that done before you do anything else. You cannot test your performance without those readings.
I would also recommend finding an experienced buddy to help you out.
One more thing, if your prop isn't new or you didn't have it tuned up by a performance prop shop then you have no idea the true condition of it. I don't care how pretty and shiny it is, that means nothing.

[javelin90]

The 80psi cylinder readings was it the bottom two cylinder on each side? As mentioned carbon define would be good. Another thing I the stratos 21ss is that the rub rail on the stern tends to leak under the water line. Are you having issues with the bilge being full of water?

[slickrick6922]

The 80psi cylinder readings was it the bottom two cylinder on each side? As mentioned carbon define would be good. Another thing I the stratos 21ss is that the rub rail on the stern tends to leak under the water line. Are you having issues with the bilge being full of water?

[bassdogg]

Bottom two cylinders were 80.
I did find in the manual that if they are less than 15psi apart, I should be in good shape. I will plan to decarb. There is a BRP product that I can screw onto the primer lever to decarb, I just forget the name of it.
Do you guys decarb in the driveway, or hit the lake? I usually hit the lake, but I ripped the dash apart to get part numbers for the Tach and water pressure gauge. Can I use just about any gauge? They are both Faria guages, but the RPM gauge has the Startos name and "logo" on it. I assume I can just stick with Faria?

Also, I mentioned my 3 blade was a 26P Raker, but it's actually a Raker II

I am having water issues in the bilge, but I also get a lot of backwash if I don't gun it when I'm coming to a stop. Rub rail doesn't sit below the water line

[javelin90]

Brp makes product called engine detuner. You can attach it to the shrader valve.
I now have a 205 yamaha ox66.
I clean the carbon off the heads one of two ways.
1. hook remote gast tank with yamaha ring free and double 2 oz per gallon of gas. using 2 gallons and let it soak it in through gas line.
2. Remove kill switch and tilt motor 75 degrees forward with plugs out and spray lots of seafoam deep creek in each of the 6 cylinders. With a tray underneath the lower unit just in case any oil drips out from power head not to stain driveway. Ilet it sit 24 hours. then crank it again with plugs still out level and then put plugs in. Go to lake and let it idle/warm up and then run it w.o.t. Once i get home i use my boroscope and remove the plugs and look in each cylinder. I then install new plugs as the old ones are fouled from the carbon from the heads.

Carol at C & O Marine in Tenn will have the gauges. The gauges are black face with gold dials and stratos inside the glass bezel.

To verify if there is a leak in the bilge do these things.
1. launch boat at ramp and slide off trailer with rope, no motor power. Open compartment battery door and if you have a boroscope/inspection camera run camera under the middle tray and look at the livewell valves, hoses ,and fittings.
2. next with a friend at the wheel, start up motor with battery door open and use camera and have friend put it in reverse a couple of times decent power and look for any water passing from the screw holes, or top cap where the marry the hull and top cap. Livewell valves over time get brittle and crack at the hose connections or in the 90 degree bends.

[javelin90]

When you perform a compression test, do it immediately with the kill switch removed on the boat trailer and throttle plates in wide open position. If not on lake do it at home after running on ear muffs. It is best to do compression test after motor is warm. f the bottom two cylinders have lower compression that the average of the other 4 cylinders then you should be able to de tune the motor. Just make sure when you use an engine detuner or seafoam you look at how much carbon has built up inside the spark plug holes. If carbon is overly excessive detuning the engine could cause the carbon to break free from the rings and get caught up on cylinder walls and exit the exhaust and then a rebuild would be required.
Keep us posted on results

[tdt91]

OP, one more thing, use the OMC props as spares and get a 25 Trophy plus. Use a Michigan Wheel #200 hub kit. Your welcome.

[bassdogg]

Thanks guys.
Looks like I have some work to do this weekend. I bought the BRP Engine tune and spray nozzle that hooks up to the primer solenoid valve. I think I have some Deep Creap too.
I was asking about the gauges because I don't want to pay an arm and a leg for two gauges at C&O, but I will call and check prices.
I'll look into that Trophy Plus, thanks

[javelin90]

You can use any water and tach gauge. I was suggesting same gauge as wire placement would be simple.

[mactlman]

Thanks guys.
Looks like I have some work to do this weekend. I bought the BRP Engine tune and spray nozzle that hooks up to the primer solenoid valve. I think I have some Deep Creap too.
I was asking about the gauges because I don't want to pay an arm and a leg for two gauges at C&O, but I will call and check prices.
I'll look into that Trophy Plus, thanks

don't decarb in the driveway -it will stain badly

[Finlander]

I saw 74 out of my 07 225 HO Etec powered 201. Same hull but newer motor. The old OMC 225 should get you to 70 but you need to go back to the 26 and that 26 may need some tuning up? I was spinning a 27 Tempest and gave her time to develop 74. It rocketed to 65 then creeped up the last little bit. Speed comes at a hole shot price, you will need to play games with lift and hole shot plates to help that big wheel out of the hole.