Yamaha F115 vs F90 - Quintrex 510 Cruiseabout

[Sifor10]

Hello all

In the market for a new boat (likely the Quintrex 510 Cruiseabout) and am considering Yamaha engine pairings.

The F90 looks great and is excellent on fuel consumption as well. See data here for the 490 cruiseabout (20cm shorter than the 510). The 510 cruiseabout is probably only an extra 50kg heavier than the 490 cruiseabout so I'd assume the performance loss would only be minor (5% if that) going with the F90.

I'm wondering if the F115 (max HP for the hull) is a good idea or not. See data here of a comparable sized boat.

I think the F115 will probably give higher top end speed, but for fuel economy at the same speeds, the F90 looks to be the better option.

Thoughts? Planning to pull the trigger at the Brisbane boat show next weekend.

[PixieAU]

I'm happy with my Suzuki 90 on my 5.6m Quinnie Classic. Great economy and only ever go WOT on glass out days anyway.

Sent from my G8141 using Tapatalk

[swof63]

Both f90 and f115 use the same 1.8l block. Mid-range fuel economy will be similar. They will have similar low-end grunt but the 115 will have a higher top-end speed but probably not by a huge margin. Interestingly the 115 has a Dohc 16 valve head where the 90 has a sohc 16 valve head. Normally the dohc design revs out better.


Sent from my iPad using Ausfish forums

[Vromme]

Rarely do you you here someone saying they have too much horsepower.

Id always go to the limit, better to spend a few extra $ now.

[Sifor10]

Thanks guys, it might come down to the $$, I'm starting to think there is probably bugger all in it, and I never 'cruise' at WOT...

[getadog]

I upgraded to the f115 yammie on my 5.1m plate boat after retiring a merc 90 four stroke (which was the yammie power head anyway). The power difference is definitely a bonus and don't work this motor as hard cruising or when playing with tow toys with the family. Best of all uses less fuel, though hard to compare as the 90 had carbs and not fuel injected. The weights on both are the same, so I would suggest go the max HP your hull is rated. Top end speed did not change on my hull as this is restricted by hull types In my opinion, and I propped it for my style of usage. Everyone is different with that respect to boating/propping just spend the time to get this right.

[Skusto]

Thought the new 90 Yamaha was lighter then the 115, reason the 90 is sohc not Dohc?

Could be wrong though?


Sent from my iPhone using Ausfish forums

[getadog]

Just to clear up my comment on weights, I was referring to the older merc/ yammie 90 being the same as the current f115 yammie. That sold it for me. I did not look into the current 90 or 100 HP weights when shopping around. Most important is propping and set up IMO.

[NAGG]

I think you'll find the 115 will be a better match for the 510 ...... there is a fairly decent power to weight advantage going up to the 115 - an extra 10kgs but gain an extra 25hp is significant .
The other point to consider is that while you might only be going up 25kgs in hull weight (490vs510) you also add an extra 25lt of fuel. Then if you add things like a second battery and it really starts to add up .
How many people will you have in the boat ? (keeping in mind that it is a bowrider) ..... if you had 3 or 4 you will be wishing that you had every extra horse you could get your hands on - that is for sure

Chris

[Sifor10]

Great points all.

I acknowledge the 25hp is a difference, but going off some of the real world tests (see my original post) it appeared as though most of the additional power was coming on at the top end.

I think it might come down to cost (as it always does) - if there is not much between the two, I guess why not go for bigger.

[NomadNoosa]

What is the cost difference?

I've got a 510 with 115hp Merc on it. If your anywhere on the sunny coast and want to go for a blat I'm happy to go for a run.

Cheers

[Sifor10]

I'll find out at the Brisbane boat show on the weekend - appreciate your offer NomadNoosa, unfortunately I'm a bit too far down south though!

Out of interest, is the 510 easy enough to single hand launch and retrieve?

[NomadNoosa]

Yeah. Very easy.