Speed not what it was promised...

[bkft]

I just bought an '06 Alumacraft 175 TP with an '07 Suzuki DF140. I'm in the stage of warm-up where I can hit full throttle, but not for more than a couple minutes at a time. My problem is that I have not yet exceeded 35 mph with only myself and 1/3 tank of gas. The dealer told me I would be able to hit the mid 40s easily. Is this something I should be concerned about, or is it natural for the motor to gain some speed after the full warm-up period? Could it possibly be an incorrectly-pitched prop (which is SS)? I'm sorry I don't know the current pitch, off-hand. Any suggestions are greatly appreciated.

Thanks!

John

[bassNspear]

When you break in the motor, it is going to get to a point where they are going to loosen up a bit. The more you get throw the breaken period, the motor itself will loosen up.

Im not sure if your going to get 10 mph more out of it, but you will gain a few more mph.

[marine_man]

Bass N Spear is right on here.

Any idea what kind of RPM's you're seeing at WOT? I would wait to do any changing of things unti after you've completed the break-in procedure, but there's a chance the reason you're not hitting your target speed is because it's not propped correctly. Providing your WOT RPM's would be helpfull in making this determination.

marine_man

[DRH1175]

Your motor will loosen up quite a bit with time. There are a few other things to consider. Prop? Weight etc... What were your RPM's at WOT, and what prop did they put on that motor? With that said honestly. You are not going to like this. But I think 38-42 is about all you could ever expect out of that combo. Unless you are a speed demon you still should be quite happy out of that rig. If speed was your main goal I would have gone with the 150 or 175 personally. However the DF 140 would be a little more fishing friendly trolling down etc...

[snowman678]

One other thing to consider would be how the motor was trimmed. If it's all the way down, it will rob probably 2-3 mph from a properly trimmed motor. I agree w/ you guys on the break-in period. As for the speed, I would think low to mid 40's is about where you'll end up. I've got a 2000 TP 175 w/ 100hp Yamaha 4/S, that will hit a max of about 35-36 on gps with only me in the boat & the motor trimmed all the way up.

[bkft]

I was pushing about 6000 RPMs to get to 35.

I absolutely love how quiet and smooth the motor is. I'm no speed freak. I was just curious if the dealer swindled me or not.

There were a couple other things on the boat that made me raise my eyebrows when I picked it up: no quick-release TM bracket like I asked for, missing some minor non-vital screws and one of the guages was upside-down -- seriously. It just seemed that the boat was kinda thrown together hap-hazardly. And when I bring these issues up to the dealer, they react as though it's inconvenient for them to fix these little problems. Am I wrong thinking those things are completely their responsibility to take care of? Anyway, sorry for the mini-rant. I greatly appreciate your responses. I'll wait until the warm-up period is done, then see what we get.

Thanks again,

John

[bkft]

Quote:

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One other thing to consider would be how the motor was trimmed.

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Yup, sorry I forgot to mention that I did trim up a little bit. Thanks, Snowman.

[Black_Bay]

I'd take it back to the dealer and have them set the boat up correctly this time.

BTW Did you buy the boat in Bloomington?

[bkft]

Yep, I sure did. I was surprised. I've dealt with them before and had relatively good experiences, so I don't want to bash them too bad. I mean, you should pretty much take their selling shtick with a grain of salt. I do, anyway, but this just kinda left a bad taste in my mouth. For the amount of money I just spent at their shop, I expected to walk in and see them detailing the boat with a toothbrush, ya know?

[marine_man]

When you say you trimmed up a little bit, please describe a little bit. What you should do is once you're on plane trim the motor up until the boat starts to porpise then trim it back down until the porposing stops. That's your ideal running position where you will get max RPM and max speed (and consequently max fuel consumption). From the sounds of it you're not running there yet. Max RPM on your motor is 6200 RPM, and if it were me that's where I'd want it. It sounds like if you trim it out the rest of the way you might be close.

As I said before, complete your break in, run your motor at the trim level described above, then come back and let us know where you're at.

I'd be a bit dissapointed as well in regard to the delivered boat - especially if a gauge was upside down. Regardless of how they feel, they should get it right, in regard to the trolling motor bracket - is it on the purchase order / work order? There is often a lot of miscommuniation between the sales department and rigging department at any dealer... if it's not on the purchase order you might have a hard time getting them to cough that up.

Good Luck!

marine_man

[LundExplorer]

I have the same motor, 2005 model year, on a 18.5' mirrocraft aluminum fish ski combo - a similarly sized boat I'd assume if not a little heavier. Motor is just past the breakin point.

I get in the mid 40's MPH @ 6100-6200 WOT with a 14x21 (stock) aluminum prop, 3 bladed.

If I'm plowing some water it will drop speed more than the 2-3mph as suggested before. I didn't really notice any difference before or after the break-in period for top speed, although I did not have at wide open much at all during it.

I think you're problem is in correct propping and getting it out on plane in the sweet spot.

[thebman]

I have that same motor on my 386XF which is a bit heavier than your boat. Last weekend I had 4 big guys in the boat, gear, and full tank of gas and a 13.25x21 Hustler aluminum prop(lake full of rocks) and got 40 mph when fully trimmed up at 6000 rpm. I think your not trimming up all the way like you should for max speed. When trimmed down I lose more than 2-3 mph as stated by others as well. Just myself in the boat with a 13.25x21 SS prop I got 44 mph. This motor is not a really a top speed motor but it is rock solid and performs well when it is properly set-up for your boat.

[iffwalleyes]

Then it is not even close to set up right if you are pushing 6K on RPMs and only getting that for your speed. I have the same motor in a Johnson version I run a 13.25x23 hustler alum pitch prop and I get 40-45 MPH depending on the load and I run about 5600-5800 RPMS on my 1775 PROV. I have gotten than pretty consistantly for my speed even during the break in period. I love the set up the motor is awesome quit allows you to care on a conversion.

[bkft]

That's kinda what I was afraid of. I'll go through the rest of the break-in time, trim up more and see how it goes. If I'm still not breaking 40, I'll have to take it in I guess.

Thanks for all the help everyone.

[iffwalleyes]

Check the pitch of the prop and let us know. You should not have to buy a new one if they put the wrong one on to begin with. See what it is you should be running a 21 or 23 like we mentioned. These motor are a little different to prop than other boats. Also make sure you are trimming it up if you are just trimming it a litte it isn't enough. Trim it all the way down drop the hammer and start rasing the motor and you will feel the speed increase you will know when it is to much.

[B-bear]

BKFT,

I have a 2003 Alumacraft TP Single console with the 140 4 strk Johnson. Basically the same boat with the same motor since Johnson bought the 140 Suzuki from them and painted it white. When I picked mine up it was the same as yours (slower than anticipated) but my RPM's were around 5800 WOT. That was on the 21 pitch alum prop. I switched to the 19 pitch alum prop and my RPM's went up to 6100-6200 which is where it should be and my speed also increased to low to mid 40 mph. The 19 might give you too high of RPM's. They didn't make a stock 20 pitch for the Johnson at that time for me to try so maybe you could try to get one for Suzuki ---if they make it now??