More power!

[hydroforce3]

hi guys i currently own a honda 10hp four stroke 06 model outboard and just recently upgraded my boat to a slightly larger size. Now with me a passenger and tackle it seems to have lost power even at WOT (like a fully loaded car going up a hill), I've even installed hydrofoils to see if it would help the stern lift to help us get back on plane which has helped ALOT but still guttered about lack of speed. now instead of me and my passenger (normally my girlfriend) going on a Beckham diet and probably being made homeless after I suggest she diets... Is there any quick easy engine upgrade I can do to gain even a smidge more power WITHOUT the expense of a totally different engine as I like the honda outboard reliability and simply can't afford to fork out for a totally different engine.

hope this makes sense guys thanks

Dan

[paintman]

What's the WOT revs in the new boat with the current prop & does this fall within Honda's given range for the engine?
Is the engine mounted at the right height & the correct shaft length for the boat?
What's the boat & what's the recommended engine hp band for that boat?

[jeffstevens763@g]

https://www.google.co.uk/search?q=co...w=1024&bih=748

Don't know if this is the same engine but this states you can get 13 hp by just adjusting a screw and I know you can do the same with yam 2 strokes

[hydroforce3]

hi, paintman i haven't got a clue on what is max revs are as I have no console or gauge, the engine is mounted at the right height as the cavitation plate sits at half an inch below the lowest part of the transom and its the right shaft length a short shaft at 17". the new boat I have is a 3.4m seapro an upgrade from a 3m hydroforce so not much of a jump and the max hp rating for the seapro is 15hp.

thanks for your replies guys

[paintman]

Likely your props wrong for the bigger - and heavier - boat.
E.g you've got a 20 pitch prop when an 18 pitch would be better. (Those are just for example, I don't know the prop range for your engine)
That said, without knowing your WOT with the current prop difficult for people to suggest what might be best.

IIRC there are some threads discussing using a 'tiny tach' on engines where no tacho is fitted to engine or boat so be worth look.

You could also post what prop you are currently using & with a bit of luck someone with the same setup could advise.

[willk]

In addition to the above ideas, are you absolutely sure you have achieved the correct pressures in the various compartments of the new boat? Have you tried moving weight forward when trying to plane - i.e. are you using a tiller extension? Have you managed to plane "one up"? Those doel fins will take some top-end away - if you can manage to get on the plane without, I'd get shot of them...

[jeffstevens763@g]

The boat weights are roughly the same 45/43 kg unless the seapro is an heavy duty at 58 kg if it's an air deck as willk says pressures are key and th.e correct prop and rpm plus trim setting are also key acording to the tech stuff the sea pro planes with 4 people with a 15 hp so your 10 hp should be ok £20 will get you a tacko start from there with correct pressures loose the dolfin and try that you can refit if needed.

[hydroforce3]

awesome guys il look into getting a small tach and gather some figures and repost as soon as the weather breaks and allows me to test. as far as weight balancement in the boat i have made my own tiller extension out of PVC pipe and is long enough for me to sit mid to front and operate the tiller from there i have my anchor and drybag and battery for my lowrance at bow, us in the middle and fuel tank and tackle at the stern and the only way i can sort of "plane" is with the use of hydrofoils and WOT, like you guys have suggested a tach and prop specs are looking like the problem.

thanks for your advice guys i will get back to you all as soon as i can get more info of RPM'S and prop size

cheers

Dan