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hellbents-10
08-01-2022, 01:23 PM
Looking to build another Tuff 16 and we ran a 90 Yamaha on the last one with the power to weight ratio being about the best option.

Does anything come close to the 90hp in terms of weight, reliability, fuel consumption, and packaging?
sharpeye Mike
08-01-2022, 05:21 PM
Didn't the owner of Tuff boats put a V6 on a 16?
There's a video out there with a V6 Merc doing 90 some MPH
If it was my boat, I would put a V4
David
08-01-2022, 07:46 PM
Mark ran a 16’ Tuff with a Merc 150. I think it was a Promax, but it’s been a long time. 90, 92? The motor was a loaner from someone I once knew in Windsor.

At any rate, it was too much weight for general use. If it was me, I’d go with the 90 Yamaha. It’s not like anyone has been making lightweight engines lately. The V4 crossflows are probably a bit heavier, but could be more powerful.
pcrussell50
08-02-2022, 01:21 AM
At any rate, it was too much weight for general use. If it was me, I’d go with the 90 Yamaha. It’s not like anyone has been making lightweight engines lately. The V4 crossflows are probably a bit heavier, but could be more powerful.

The “bubbleback” V4 cross flows, before prop rating were 135 and 140hp, if I have my facts straight, and after prop rating, were sold as 110 and 115 hp. So if you get a bubble back, you might be getting more than 90hp prop.

I have a 1975 135 (so probably 110 today?). With factory high compression heads, stock. It’s got a crackling high compression idle on the muffs. I never get tired of hearing it, although it’s sitting on a stand, unused at the moment. It’s also pretty light. I’m quite sure it’s lighter than the 1993 115 I have as well.

-Peter
hellbents-10
08-02-2022, 12:26 PM
What is the weight on the v4s? I think 300lbs is more then I care to go.

I think 250lbs at 100-110hp would run a easy 75mph.
David
08-02-2022, 03:45 PM
From the 1991 Johnson brochure, a GT100 weighed 301 lb, and a 115 was listed at 306 lb. In 1999 Yamaha was claiming 256 lb for the 90 HP triple.

Hydrotech says they can get another 10 HP out of the 90 Yamaha HT 9084 Phase Kit 1984-2009 75-85-90hp Yamaha (hydrotecmarine.com) (https://shop.hydrotecmarine.com/product.sc?productId=109&categoryId=2)

No doubt there is more power in the stock V4 crosssflow, and it can be modified.