Does anyone have a Yamaha 60hp 4 stroke?

[Cruize]

I just had a yammay 60hp 4 stroke fitted to a 14' glass boat and so far I have lost 30% top end speed compared to what I used to get out of my 70 Jonny 2 stroke.

I was expecting a bit of a drop but not that much! I was advised to expect little or no difference.

If you have a 60hp 4 stroke could you let me know what sort of performace you are getting. I think something is wrong.

Any advise, PLEASE.

[Poseidon]

I have a 60HP 4 Stroke Mercury EFI (same kinda motor ?) fitted to a 4.35m 3mm Aluminium boat, underfloor fuel tank, live well and other weighty things.

At WOT 6000 rpm we can get around 57klm / hr (GPS).

Hope this helps.

Regards Cameron.

[dan099]

hi mate i have a 60 4 stroke on a 4.58 streaker and i went back from a 90 evenrude . i lost about 3 knt top end speed but acheived much more as it uses very little fuel and no noise or smoke to speek of

top speed 29 knt with 2 men and fishing gear 5900rpm
cruise at 21 nts @4200 rpm

[simonfish]

Hi, I have a f60det (yamaha 60 4stroke high thrust, so bigger gear box) on a 445 hornet (hull weight around 330kg). I get 30knots at 5700rpm, and am spinning a 13 1/4 * 15 pitch alloy prop.
I am getting the engine lifted one hole, as the cav plate is about 30mm below the hull and I believe this will give me another 200-300 rpm, as well as another couple of knots (less leg in the water, less drag)

I find that sometimes the engines are fitted a tad low, which increases drag and can affect performance, also, the prop choice is critical. In my experience, the f60 works best when WOT is around 5800-6000, so probably a 13 - 15pitch prop (I had a boat once and the dealer fitted an 11pitch prop, boat did 24knots with WOT of 6100, changed to a 13pitch and it got 29knots at WOT of 5800!,I think we lifted the leg one hole as well)

hope this helps.
cheers,
Simon

[Cruize]

Thanks guys - my top speed is 19.5knotts at max rpm! and it doesn't go past 5900rpm - it misses at 6000rpm. I hope it gets better or I wasted $8500.

I got the bigger gear box too.

[simonfish]

Cruize, what prop do you have ? mine is 13 1/4 * 15pitch alloy

[daz35]

it would pay to have a play around with different props as i have a merc 60 on a 535 cc and i get 60 klm at 6000 rpm but put the standard prop on and it is like a slug .i will have to have a look and see what the prop is on now and let u know

[FNQCairns]

Hi cruise sorry to hear you got conned, but it will never ever do what your 70 2s could do, you would need the next sized 4s out there 90hp? to equal or better the 70hp johnson. At least there are other qualities to 4s ownership.

I am currently looking at powering a boat and will probably be choosing the 75 merc, although I have no complaint over owning a 4 stroke I know I will need to go 115hp to get comparable or margianally better performance than the 75 2s. VERY hard to justify that extra price tag even ove 20 years of ownership!.

It's just a shame also.

cheers fnq

[dnej]

FNQ,
you and I spoke about this ,when I was looking at the same issue,and we agreed,that a 60 hp,cant do what a 70 hp can

The same issue keeps raising its head,that a 60 hp 4 stroke ,will be as good as a 70 hp two stroke.
Why do they keep saying this ,about this particular motor?. Makes me wonder.
David

[Cruize]

Thanks again guys - I appreciate your input. Keep it coming please.

I don't yet know but I think I'll have to learn about prop set ups - the shop guy told me but I didn't understand the importance - I do now! But I thought he said he said he put the 14" to match the bigger gear box and to get best performance. I'll check again!

I am not being unrealastic - even though the shop guys said "very little if any diff at top end" I was expecting some but not at this level - I would have bought the 80hp if they had suggested it - but two seperate peolple said the 60 would be enough. Bullsh-t!

DAZ - WHAT PROP YOU GOT!

SIMON - I'LL ASK ABOUT LIFTING THE MOTOR AND PITCH.

[cajunnsw]

If the Yammie still has the prop that it comes with in the box, you will be very dissapointed. These were made for the houseboat trade.

My dealer exchanged props, and my 60hp High Thrust Yammie, is at least the equal of my early 80's 70hp Johnno in hole shot, and top end speed. Craps all over it for the extras Noise, fumes etc.

I am very happy with the purchase.

I also find that the boat (4.5 lazeabout) is now much more sensitive to trim. I get WOT 5700 revs.

Like the others have suggested, check the prop.

Cheers
Ken

[Cruize]

Thanks Ken

You know - I emailed the place where I git it from and they haven't bothered to return yet. I asked what prop and told em my problem.

I hope they do or I'll be ringing them and not so happy >

[FNQCairns]

IMO sometimes and often in outboard sales, any sale is a good sale, thinking around your problem, is your speed GPS? and is the wot RPM and speed with a light boat or heavy or inbetween.

4 strokes rely on low pitched props (compared to equivalent 2st engines) combined with an extra WOT RPM like 500 (compared to equivalent 2st) or so to make up for the sharp proping needed to get performance at all other RPM's.

This leads me to wonder? are you really getting 5900? and if it misses at 6000 how much further could you go? Sounds like either your tacho is out or on the wrong pole or you have a prop that is even too sharp for a 4 stroke (hence the low max speed) - how is your pickup out of the hole?

Anyway just some thoughts, it's easy to work out what speed you should be doing with a prop calculator, write up your MAX rpm and speed obtained also the pitch of your prop, diameter can be usefull also.

cheers fnq

[mirage]

Cruize, Give Steve at Solas props on the Sunshine coast a call. He will know how to sort out your prop/power problem. You should be getting much better performance than that.
A friend of mine just replaced his 70hp 2stks with the Yammy 60 high thrust on his 5.2m Kevlacat and he is very happy with them.
Good Luck.

[daz35]

cruize i got interstate visitors so havnt had much time will have to pull prop off to have a look in the next day or two.the mate i bought the boat off doesnt remember but he did take it to solas up the coast and they water tested it with different props till they found the right one as mirage says it would pay to give them a call on 1800333342 or 54379400