New DF140 Breakin time vs RPM

[racehydro]

My boat had a 2004 DF140 on it that went 37 MPH at 6150 RPM.

This winter I had a brand new DF140 installed (but kept the original prop), and went through the 10 hour break in period per the Suzuki manual.

Now, at 20 hours, with the same boat, same prop (from the original engine), same engine height, and same load in the boat, the new engine only goes 30 MPH at 5600 RPM. The boat is slow to get on plane and slow to reach top RPM.

The dealer claims that the engine is still tight and needs at least 50 hours of run time and then the RPMs and speed will increase. Does this make sense to you guys? Would really like to hear your experience with breaking in a new engine.

Thanks,
Race

[Moonlighter]

The gear ratio on the early 140's like your 2004 model is not the same as the later and current 140's.

So you have the wrong size prop for the new engine.

You didnt say what size the current prop is, but a SS Suzuki 14 x 20 is a common and popular size. Of course this will depend on your boat.

The motors do loosen up further after 80- 100 hrs but the result is not going to be anywhere near picking up 400 rpm to get you to 6000. Typically you might get another 100rpm but fuel economy is the main gain.

As I say, wrong size prop is the problem, due to different gear ratios.

[racehydro]

Moonligher: Thanks for the reply. Your advice sounds much more accurate.

I have been running a Michigan 3x14x17 aluminum prop. The gear ratio on the original engine is 2.38:1, and on the new engine it is 2.59:1. Seems like the new 140 could use more pitch with a lower gear ratio. Wouldn't the 17" prop be to small and cause it to rev higher? Or I am I not understanding the gear ratio change?

Given I was running the 14 x 17" prop on the old 140, what would you recommend for the new 140?

Thank you!

[Moonlighter]

Running a 14 x 17" now?? That makes me wonder what is going on!! Something does not sound right - maybe engine just isnt running right for some reason. Maybe the throttle cables are not set right and you are not actually getting full throttle? It needs to be checked out.

The new engine is in fact much stronger than the old one. So out of the box it should have your boat performing better than the old one. One of the reasons the gear ratio was changed was to address sluggish out of the hole performance.

I dont know your boat or its weight etc. so cannot suggest a prop. But something does sounds wrong. I run a 14 x 20" Suzuki stainless prop on my Df115 and pull 35knots. 18ft heavy duty alloy cuddy cab.

If I was you, I would be back at my dealer pronto to have it all checked out, to make sure the motor is running properly, set up correctly, is in fact getting full throttle, and to then work with the dealer to get a prop that works properly with your setup.

[racehydro]

I went back to the dealer and they said the engine is fine - your prop is bad. So I went home and pulled off all the cowlings and air intake box. Just as you suggested Moonlighter, the throttle was set to only open about 3/4 of the way. Of course the dealer swears they set it correctly.

Trying to figure out how to adjust it to get full throttle. There is not enough threads left on the cable connector to the pivot pin on the engine throttle assembly to get it to go full throttle. There must be some adjustment on the remote throttle I have to adjust to get full throttle??

Thanks!

[Moonlighter]

Get the dealer to fix it, snd insist on watching as they do it!! Talk to the dealership owner about the issue.

I still think you will need a different prop.

[racehydro]

Moonligheter: I went back to the dealership and they just blew me off and wanted to charge for a sea to 'figure out if there really was a problem'. This is after I told them the throttle was not adjusted correctly!!!

I took the boat home and adjusted the throttle myself. It is a whole new boat! I switched to my original 14x19 Suzuki prop and it runs great, planes fast, and will probably get a 14 x 21 prop.

I called the dealer to tell him about it and they just said - great, glad you are happy. The owner didn't have time to talk with me. I told them I was not happy and would spend my money elsewhere with competent mechanics.

Thank you SO MUCH for the help and encouragement. It is such a huge blessing to have you and other fellow Suzuki owners on this board help those that are less knowledgeable.

My best to you!

Get the dealer to fix it, snd insist on watching as they do it!! Talk to the dealership owner about the issue.

I still think you will need a different prop.

[Moonlighter]

Glad you have it sorted out. Happy to help where I can.

That is very disappointing that your dealer treated you like that. I would be very tempted to contact Suzuki HQ and inform them of your experience. I doubt if they would be happy at all, about that.

If you can afford it, the Suzuki 14 x 20 stainless is a very good prop on the 115/140 engines. Just seems to grip up nicely and performs great.

[racehydro]

I have written a letter to the owner of the dealership and will send a copy to Suzuki.

Going to test the boat some more and then order a new prop. I looked into the 14x20 SS and it looks great. Sounds like it would be perfect for my setup! Wish I could try it first but probably will have to own it first.

Thanks again!

Glad you have it sorted out. Happy to help where I can.

That is very disappointing that your dealer treated you like that. I would be very tempted to contact Suzuki HQ and inform them of your experience. I doubt if they would be happy at all, about that.

If you can afford it, the Suzuki 14 x 20 stainless is a very good prop on the 115/140 engines. Just seems to grip up nicely and performs great.