Suzuki DF70A or DF90A uprade from Honda BF50 carb?

[milest]

Hi everybody,
What is your suggestions about that upgrade? Suzi 70 is $8000 and 90 is $9000.I have prop options as 3X14X13 and 3X13 7/8X15 for a 26

Thanks in advance,

[Starscream]

If you are going to spend 8k on the first 20HP upgrade you might as well spend 1k extra on the second 20HP upgrade.

If you don't you're gonna wish you did

I would not have been happy with a 70HP. I am actually a bit disappointed on the trade in from my BF50 to an ETEC 90 with regards to top end performance. I'll blame it on the bumpy bottom-paint for now.

[Erik Hardtle]

Go big or stay home!!! Hhhehe....

Here is why you should go 90hp!

https://www.youtube.com/watch?v=eQafizZpamE

or this:

https://www.youtube.com/watch?v=dBPSK5m6WfE

I used to have a Honda 50, and it had a tough time getting out of the "porpoise" mode. I have a lot of weight on my boat (see web page) and 4 people most times... the 90 really got me up and going.

Here is my install:
http://www.enctrader.com/hardtlefamily/ ... ineupgrade

I did change to 4 blade prop as well... never use stainless steel, always aluminum as I favor cleaning the blades in the sand or on rocks!
___________________________________________________________
Capt Erik, Admiral Jean, First Mate Christina & Swabbie Nicole
1999 MacGregor 26X, "KnotShore"
New Bern, NC

[dlandersson]

Unless you have a specific objective in mind, whatever you upgrade to will leave you wondering if "20 more will do the trick".

The admiral told many times - starting on our honeymoon, that "size is not important" - so it must be true.

Hi everybody,
What is your suggestions about that upgrade? Suzi 70 is $8000 and 90 is $9000.I have prop options as 3X14X13 and 3X13 7/8X15 for a 26

Thanks in advance,

[mrron_tx]

I have the Suzuki DF70A and have no complaints.... But that's just Me Ron.

[Russ]

Go big or stay home!!! Hhhehe....

Here is why you should go 90hp!

https://www.youtube.com/watch?v=eQafizZpamE

or this:

https://www.youtube.com/watch?v=dBPSK5m6WfE

Dang!! That's awesome!

If I didn't have a perfectly good DF70 I'd upgrade mine to that 90.

[bahama bound]

When I was just pricing motors they kept telling me that Suzuki 70 and 90 we identical and I would be hard pressed to tell the difference? The suzuki's I priced were really reasonable,like 6200 for 70 and 8200 for 90 ? At least for now I'm really happy with etecs !

[milest]

Thanks guys..

I want a quiter 6-8 mph cruising.Of course it sounds better 20 more bhp for $1K. It would be fine if anyone has tested 70 and 90 and compare them. For the same 1.5 Lt. engine, if I have benefits of that 20 more ponies after 5000 rpm it's not so important to me.Can I feel the difference 1500 to 5000 rpm? What about the prop choices that I have?
Thanks,

[Starscream]

Prop choices will depend on your boat load and condition. Unpredictable, I have learned.

For example, BahamaBound and I have the same boat and the same motor, but mine can only swing a 14x11x4 while his can turn a 14x15x4 (If I remember correctly). Frkn bottom-paint, yeah, that must be it!

With a 70HP I'd be tempted to start with a 14x9x4-blade if your boat is light and "clean". Your options listed on your original post have too much pitch even for my 90HP. Maybe the 3-blade prop changes things, but from everything I have read a 4-blade is the right choice for the Macs.

Anyway, if you buy the motor from a dealer they should give you a best-guess prop to start with, maybe even a used one, and then use your results to figure out the correct size new prop to put on. Don't overthink the prop: they are so easy to change and a good motor dealer will have no problem to supply several trial props in order to get the right one.

[Seapup]

Thanks guys..

I want a quiter 6-8 mph cruising.Of course it sounds better 20 more bhp for $1K. It would be fine if anyone has tested 70 and 90 and compare them. For the same 1.5 Lt. engine, if I have benefits of that 20 more ponies after 5000 rpm it's not so important to me. Can I feel the difference 1500 to 5000 rpm? What about the prop choices that I have?
Thanks,

I took a quick look at your other posts and it looks like you have been contemplating swapping out the Honda for awile.

Victor has done the prop experimentation and repitching for the DF90A and has posted excellent results.

Suzuki has boat test results for the DF70a & 90a 1.5L on their site. It looks like fuel consumption/speed are about identical below 2000rpm, then start spreading with both motors topping at around 6k. The fuel consumption goes way up on the 90 relative to the 70 from 5-6k so you are probably spot on and would notice minimal differences at 6-8mph.

At 6-8 mph there is not much slip, so over propping for lower RPM is one way to achieve that. I have read of Gemini catamarans running the BF50 way over propped for better fuel consumption/lower rpm cruise speed since it cant go over hull speed.

Not sure your area, but if you check any of the Va/Nc Craigslist there is a dealer advertising the Df70a for $6495, I emailed them about the Df90a and its $7295 and the new DF115a is $7395. I was thinking about the 115...I wished I had it after I bought the 90

[Tomfoolery]

At 6-8 mph there is not much slip, so over propping for lower RPM is one way to achieve that. I have read of Gemini catamarans running the BF50 way over propped for better fuel consumption/lower rpm cruise speed since it cant go over hull speed.

I've thought of doing something like that for cruising the Erie Canal - intentionally over-propping. But I don't travel far enough to have to worry about it, so the boat bucks go elsewhere. But it's certainly a valid idea to prop for the intended use. I use the 4-blade mainly for towing a wakeboarder (it howls at canal cruising speed). The 3-blade for 'normal' use, including canal cruising. Changing props takes minutes on the trailer, so no big deal to switch them out.

[Gazmn]

What is your suggestions about that upgrade? Suzi 70 is $8000 and 90 is $9000

A problem like this is nice to have because it's not a problem - it's a matter of choice

Should you end up regretting your choice, Then you have a problem

While money is precious, you're already in an arena [marina] where you gotta pay to play. A boatbuck, while precious, is a Small amount to pay to deter a potential problem.

I'm assuming you only want to upgrade once - not twice like I ended up doing
I'd get the biggest amount of HP/Torque I could get without getting into trouble. Given your choices that would be the DF90A.

This is the only relevant comp I saw for the 90 Vs the 70

I think the $1K upgrade [Eng software tweak] is worth the results.

Good Luck

[milest]

Thanks everybody,
Decision is made for Suzuki DF90A......and.... Should I use transom wedge of 5 degrees for a heavy 26 or not?.. Can you please give some advice for the problems about helm seat when lifting up the suzi DF90A?

Thanks so much,

[Billy]

Definitely install the wedges. The angle helps keep the nose of the boat down during acceleration. You can trim after getting on plane and pick up a few more mph.

IIRC, you can program the lift of the engine to stop at your predetermined height.

Best of luck. You'll going to love the big 4s motor.

[mrron_tx]

Thanks everybody,
Decision is made for Suzuki DF90A......and.... Should I use transom wedge of 5 degrees for a heavy 26 or not?.. Can you please give some advice for the problems about helm seat when lifting up the suzi DF90A?

Thanks so much,

Unless Your 90i smaller than My 70.... at full up....it,s gonna bump the helm seat I think I remembered to stop it ...maybe 10times..... it's not the end of the world.... just really annoying Ron