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fishinwahbee
29-07-2011, 07:35 AM
hi all,
Ive recently done a post on this subject and it seem that it isnt possible. With saying this i know that people have done it before. several motors on ebay ive seen have been upgraded form 6hp to 8hp. Recently ive seen a motor that has had a 9.9hp carb put on it. Your thoughts fellas/gents please.

Cheers fishinwahbee

Never to young to be a pro 14yo!

Feral
29-07-2011, 08:29 AM
Some motors it can be easily done, dont know about that one.
If you upgrade the HP over 6, you would need to be licenced to operate it. You may get away with it, but if there is an incident and they look at the motor, they will know (particularly if it is a well know modification such as upgrading a carb or removing a restrictor plate to give extra HP).

Noelm
29-07-2011, 09:02 AM
most HP upgrades do NOT just involve a carby or some jets, to swap the carby from a higher HP usually just works out to you having a motor that runs way too rich for little gain, simply getting more fuel into a motor does not always make it better, the fuel needs to be compressed and ignited, and the exhaust gas taken away with equal added efficiency!

finga
29-07-2011, 09:53 AM
The easiest way to get some more speed is to get rid of the weight in the boat.
Pull all the decks and stuff out and she'll fly :)
Other then that you'll just have to wait a couple of years and get your license.

cormorant
29-07-2011, 10:23 AM
Look at the parts diagrams for both motors and tick off every part, exact numbers - the full string - all letters. Only way.

2st and 4 have different issues.

Things often different as Noel says
Jets So many are fixed these days so it means changing a expensive carby.
timing
carby throat
restrictictor plates
reed block or reeds
exhaust
porting
ignition module
rev limiter
throttle stop
Airbox
head
piston.

Many people kid thems that they get better performance by fiddling and they may get better low acceleration or diferent noise but nt overall performance you may not gain much. Then when you sell the motor or someone goes to service it and puts some setting back to standard it may kill it.

Propping small motors is often forgotten due to the relative cost of props but amazing difference that allows them to rev which is where they make their power.

Weight trim and set up can make a boat much beter than playing with a motor .

I'll also say ( silly as it is) that with all the new emmission laws a propper mechanic would think twice these days in doing modifications as for the consequences along with the insurance laws if it tears a transom out ( even if it wasn't) the cause

Yes you can get more power out of any motor but there is a cost or a line in the law you generally cross and usually ompromise something else.

Noelm
29-07-2011, 10:51 AM
another thing that catches a few out, (even from the parts list) is (say) the blaock is listed for a 20 and 25HP as being the same, when in fact the replacement part you may order some time down the track will indeed be for a 25, even though you have a 20, the part number is the same, but your original 20 may not have been finished the same as the new replacement part (get what I mean) so you check the list as see both blocks have the same part number (as a replacement) when in fact the 20 was used just as is when new, but the 25 was cleaned and polished, the ports may have been enlarged and so on, it is not all "yes and no" I'm afraid.

fishinwahbee
29-07-2011, 04:05 PM
Thanks everyone, definately something to think about. Great information.
Fishinwahbee

finga
30-07-2011, 08:07 AM
Oi little matey.
Does your boat get on the plane with just you in it?

fishinwahbee
30-07-2011, 10:20 AM
Mate,
Yes my boat dose get on the plane with just me in it. The boat is a 3.7m stacer (heavy i know) which has a casting platform at rear and front. Recently i have tacken the decks and floor out to make it just that little bit lighter. I would really like the extra hp as im wanting to do a full bass setout soon. I also take many of my mates out.

Fishinwahbee

finga
30-07-2011, 11:31 AM
If I was you matey I'd forget it for a while.
The boat is performing well getting you on the plane with front and rear casting decks.
A 9 will not make that much difference. The main difference will be you may be able to get on the plane a bit quicker.
You'd be surprised how heavy decks are. i'd be leaving them out if you want to take mates.
There's only so much a little motor can do and it sounds like your motor is doing all it can.

fishinwahbee
30-07-2011, 01:50 PM
thanks mate, that makes alot of sense cheers