Overpower a Zodiac Bayrunner 550

Captain Pepe · 11 January 2015, 18:54

Hi.

We like to get a Zodiac Bayrunner 550 rated for Max 90HP.

We own in Mexico a New Mercury 115HP that weight the same as the Yamaha 90HP.

We want to overpower by 25 HP the boat. Same engine weight.

Can the boat support 115HP instead of 90HP???? Same engine weight.

Get a stainless steel prop 21 pitch for the 115 HP Mercury. The botas weights 660lbs.

Phil M · 12 January 2015, 21:03

I don't know about the newer bayrunners but my research suggested that people with 530 Pro's were getting low 40's mph with a 115, beyond which the hull started to reach its limit of stability. I hit about 38 mph in mine with a 75 2 stroke on the back, but that was on a very calm day and barely loaded. The 530 is rated to 120 though (or at least my model year was). Do you have a max engine weight on the transom plate? I too have the new merc 115 (2.1 litre 163kg), which if phenomenally light for a 4 stroke of that power and a really nice looking engine. I was planning to get the honda but the merc was released at a much better price. I haven't run it yet as I'm still fitting out the boat. Hopefully I'll get out when the seas calm a little.

Phil M

Captain Pepe · 12 January 2015, 22:59

Thanks Phil.

We did the same, Mercury release the New 115HP 4 stroke at a great price so we pay atention. Cheaper and lighter than any brand!! 115HP nice!!

The Zodiac Bayrunner 550 is rated Max 90HP and Max Engine Weight 170 kgs (transome plate Info). The New Mercury 115HP weights 163 ( the light version... the comman trust that is a bit heavier).

So.... On weight limits I am inside manufacture specifications. But on power I will be over 25HP.

In Tampico Mexico we only have Honda and Mercury. A 90 HP Honda is the same WEIGHT and PRICE as the New 115HP Mercury.

My only issue is overpower the hull by only 25HP............ Will 25 HP can really be bad? We always handle with care our boats.

Aaaashhh I will love to have the New Mercury on it. I like felt in love with the 115..... And for the price it is a good deal.

Truly Yours

Captain Pepe

Starovich · 13 January 2015, 12:01

Suppose it depends on what the insurance says, they may not cover if either weight or HP is overdone, could get issues if you ever need to claim?

Captain Pepe · 13 January 2015, 13:25

No issues with insurance or the law in Mexico. Insurance is very expensive in Mexico so I will never spend money on insurance on my boats.

Insurance works for more comercial activities.

So 25HP more!! Same engine weight! Handling with care. Boat usually 2 passengers some water ski. No heavy loads.

Can't sleep just thinking on the 115HP!

paddlers · 13 January 2015, 13:35

If you've no issues concerning insurance I think you'll enjoy the extra horses. If the top end is too fast don't use it. The acceleration alone will put a big smile on your face.

Captain Pepe · 13 January 2015, 13:39

My only and last issue is will transome can handle extra 25HP at same engine weight as the 90's HP?

Aaaashh..... Can't sleep......

Many boaters have told me that for light weight and under care no problem at all. Just don't abuse the extra power and that's it.

Phil M · 14 January 2015, 11:04

you could always add some transom brackets/braces. Either hard wood and glassed in or stainless/aluminium and bolted to the transom and floor or into a stringer. It's what I plan to do cos I'm paranoid, even though mine is under max power and less weight than some of the 120's of its era.

Phil M

Phil M · 14 January 2015, 11:05

oops - double post!