SUZUKI DF60 update to 70?

[Kimmo]

Hi!

New on the forum and have a question, I have an Gemini waverider with two DF60, with 19" propellers, topspeed is around 34 knots. Would like to achieve 40 knots and get the cruising speed comfortably around 30 knots.
1. Can I update my 60 to 70 by changing software or the engine controle modules?
2. Gains/cost?
3. Where should I get the parts?

Kimmo

[Hightower]

19" props on a 60hp....Hmmmmm. A little over propped I guess. 15" or 17" will get your engines in the right rev range and give you better acceleration and speed I suspect.

[Pete7]

A ruff and ready calculation is add 4" to the pitch of props for twins compared to a single outboard.

Do you know if the engines reach WOT ?

Pete

[Kimmo]

What is WOT?

The original props were 17" aluminium, had no grip at all, I could not trim the legs up even a bit without losing grip from the right engine. engines would of reached over 6000rpm when the recom.max is 5300 for DF60. Topspeed was 28-30 knots with aprox. 5500rpm. I was really unhappy.

So I changed those to 19" steel props and got grip.Top rpm is now 4800-5000. Boat is slower to get on plane with four people and I think it will strugle to plane with heavier loads.
May be I should of tried 17" steel?

Boats minimum hp is 90 and max 180, 115 is recomended.
DF70 recom.max.rpm is 5800. To my understanding the only difference between DF60/70 are the number stickers and engine programming?
So would the extra 10hp/engine do the trick or will I stay under powered with 70:s?

Kimmo

[Pete7]

WOT = Wide open Throttle and is normally used to decribe the maximum revs you can achieve at full speed.

Not sure about the Suzukis, but for years Mercury have made sure that you can't easily upgrade an engine from a lower hp even with simple mods. Have a chat with your nearest Suzuki dealer to see whats possible.

Also have a chat with Julie at Steel Developements about taking an inch out of your S/S props.

http://www.steeldevelopments.co.uk/

Pete

[Neil R]

Some helpful soul posted a link to this US online shop a while back. Here's the exact link to their parts manual for the DF60/70 - albeit it was not downloading very successfully for me just now.

http://store.brownspoint.com/pdf/DF60_70(98-05).pdf

If it's like the DF90/115 one I'd previously downloaded, then it should give you a detailed clue on what the differences are. For example the camshaft is definitely one of the changes on the 90/115 engines.

Overall, though, I'd be amazed if you find this a realistic proposition.

I also ordered one of the Service Manuals - and was fully happy with both the product and delivery time.

[Kimmo]

Thanks,

I checked the parts list on the Brownspoint, and there are so many parts to be changed; (camshaft, cylinderheads, throttlebody, etc) so really not worth the time and effort.

I checked the steeldevelopments also, thanks again, they are offering also a four bladed 19" propellers as "improved acceleration" version. Dont know if it would make difference in my case...

I think I will still give call to my suzuki-dealer and ask an offer for swapping the 60 to 70.

Kimmo