2005 Stratos 386 XF - 140 HP Suzuki

[kwaskow]

Runs like a top. However, it is slow to get a skier up. Are there any adjustments I can make easily...thinking premium fuel, maybe seafoam additives? It does have a sea ray planing fin on the motor.

[Harper]

Might be a matter of propping. What is your RPM at wide open throttle under your normal running conditions? It should be right up there at specs, which I'm guessing is around 6000-6200 (check your manual to be sure). If you cannot reach that RPM at WOT, you are over-propped and need to either reduce the prop diameter or the prop pitch. You need to do this not only for achieving your desired results but it is important for the longevity of the motor.

I'm no expert in towing skiers, but as I understand it, if your motor is not spinning up fast enough when pulling the skier up, you need to reduce the prop pitch, too. If you boat is used for skiing just some of the time, and maybe fishing the rest of the time, you might consider different props for the two different conditions.

[Moonlighter]

Also, check the engine height. At a good fast cruise speed, trimmed out to normal position, the anti-vent plate should not be under water. If you have a fin on there, it also should not be under water, it should be just skimming the surfac in this test.

A motor set too deep will cause excessive drag and that slows performance. It is important to get height set correctly before playing around with props, because you can easily pick up a couple hundred rpm by lifting the motor to the optimum height.

Mike is correct, on that engine at WOT you need to be hitting 6000rpm.

So:

1. Check engine height and adjust if necessary
2. Then check rpm at WOT and make sure the prop you have gets you to 6000prm. If it doesn't, change props - lower pitch.

[kwaskow]

Thanks for the feedback!
I think the RPM's would hit about 5600 at WOT with the motor trimmed all the way up. Max speed with 6 people in the boat was only about 37 MPH, but with just 2 guys I can get mid 40's.

I will check the height adjustment next time I am out.

Any other tips appreciated!

[kwaskow]

I should also mention I am running a 21 In 3 blade prop

[Harper]

If the 5600 RPM @ WOT is all you can attain in your usual load configuration, then you should reduce the pitch from 21" to around 17". The rule of thumb is each 1" reduction in pitch wil gain 100 RPM. What I'm saying is that you are lugging your motor (yes, even at 5600 RPM), You are increasing the wear and tear if you cannot reach the precribed RPMs at WOT. It is also why you are struggling to pull the skiers up out of the water.

I would suggest that you try to find a delaer who is willing to let you try a few different props. I think you will be surprised at the difference in hole-shot performance, even if you sacrifice a little top speed, which in itself may not even happen since your RPMs will be higher.

[kwaskow]

Also noteworthy is the motor gets a lot of "spray" directed up and at the back of the motor. Not accustomed to this on previous rigs

[kwaskow]

A guy has a Michigan Wheel Stainless, Cupped performance prop #013044 15x17 RH for $175. Wondering if that will fit my DF140? It seems to about what you folks have been steering me towards

[Moonlighter]

Also noteworthy is the motor gets a lot of "spray" directed up and at the back of the motor. Not accustomed to this on previous rigs

That right there is another pretty strong indicator of a motor likely set too deep!!

First task before anything else: check engine height as previously advised. Do not pass GO, do not collect $200 until this is done!

And do not buy any prop before engine height is checked and adjusted to correct height. You may pick up 200/400rpm just by getting engine lifted up to right height, and also pick up performance out of the hole.

That Michigan prop is too big diameter anyway. Your 140 takes a 14" prop. Most people find the Suzuki stainless 3 blade 14x20" is a good choice for them. I run same prop on my DF115. But again, please don't mess with props until that engine height is sorted!

[kwaskow]

Is motor depth adjustment a matter of removing the motor from the transom and moving motor up one hole in the transom brackets?

[Harper]

Yep, that's how it's done. Not easy, of course, without equipment. Renting an engine hoist is one option. I live in the country, have a tractor with a front loader and use that with a chain over the bucket. In any case you lift the motor by the two lifting eyes under the cowling.

[Moonlighter]

I'll tell you how we lift motors the easy way, without any lifting equipment! It's easy with motors up to 150-175hp!

You just need a couple of friends to help. And I am assuming you have the boat on a trailer.

Put trailer on a flat piece of ground. Disconnect from car and chock wheels so they can't move. Trim motor so it is vertical. Put some bricks or heavy block of wood under the Skeg. Then wind the jockey wheel up. This means the engine goes down, until the Skeg is now taking the weight on the block of wood you put under it. Don't worry, the Skeg is plenty strong enough to take the engine weight.

Loosen the bolts holding the engine on. Get your friends to keep the motor steady, while you remove the bolts, then they simply tilt the motor back a couple of inches so it comes away from the transom and hold it there. Clean up the sika on the transom and get some fresh sika on there and on the motor bracket.

You then run back up front to the jockey wheel and wind it up a bit more until the motor is lined up with the new hole that you want to set it on. Run back round the transom and slip the bolts in and with help from friends push motor back onto transom. Tighten bolts.

Job done. Piece of cake. Done many this way.

[Harper]

Pretty slick, Grant.

[Moonlighter]

Yeah Mike, it's a neat trick, we picked it up a few years ago when the 70 Yammy I had on my last boat was buried too deep, one of the guys had done it this way a few times before.

The best thing is you don't even need to disconnect steering, harness or anything else. And it's not hard to just keep the motor balanced, that's why with one guy on either side of the engine it's pretty easy. Naturally, you have to go steadily and keep the motor just nicely balanced on the skeg, but it is not too hard and we have never had a catastrophe so far, touch wood!

I lifted my 115 one hole using this method, so the 140 that kwaskow has is the same weight so should be easy to do too.

[kwaskow]

Update: Spent last week in Okoboji. Boat did a good job pulling my kids around. Motor height must be ok, I got it trimmed all the way up at WOT and the planing fin was just out of the water. RPM at that point was about 5800 and I am getting about 41 MPH GPS speed. As a reminder I am running a three blade 21 inch pitch prop. I would still like a better hole shot, and I am thinking that 5800 RPM is a little on the low side.

Can anyone please advise on the next course of action? Likely a prop style and/or lower pitch is in order next....