help modding a 40hp twin yammy

[serious3]

lads i'm looking for a bit of help and advice on a few simple mods i can make to my 40hp yamaha twin (6E9 model). ive had a root around the "normal" outboard forums and the advice is always "if you want more power buy a bigger motor" thing is i'm unemployed so thats out the window!
the motor is on a zapcat (thundercat, dux hammerhead type) and all my mates have the ubiquitous tohatsu 50.
i'm not after huge power id just like it to rev quicker and harder and get a few extra horses, i was thinking of lightening the flywheel for starters then maybe a set of reeds, possibly dumping the choke flaps and upping jet sizes slightly. has anyone else any ideas that can be done on the cheap by a reasonably competant man in a workshop?
thanks in advance!

[DeanFHobart]

Mill the head to get more compression and increase the ignition timing before top dead center for starters. Use a little more oil.

And as you said.... lighten the flywheel some. Balance it.

[serious3]

hallelujah!! a reply to my question that doesn't start with "trade your motor" .... she's running at 135psi at the moment. how much is the norm for milling the head? presume a couple of thou would do it! i'll start with the flywheel tommorrow after i've been out playing and got a base line figure on the gps. thanks for the reply and keep em coming!!

[byrdsperformance@tds.net]

If your saying a couple as in removing (2) thousand's ,
it wont be worth the time an gasket's.

[serious3]

so how much would you remove then?

[curbman]

take 8 to 10 thou

[fs5]

so how much would you remove then?

i dunno about the twin cyl 40hp,but over here they skim .060 off the 50hp 3cyl motors.probably best to stick with 88workcar post ,you can always skim it a bit more.

[microbream]

so how much would you remove then?

to give you an example i took 1mm (40 thou) of my twin cylinder, this increased the compression from 115 to 190psi. I run 95 octane at 30:1 and she runs hard!!

Two strokes are all about the squish clearance, my initial squish was 2.2mm, it is now 1.2mm, i could have got it down to say 0.8mm but it is risky when you take into consideration all the engine tolerances. IMO 200psi is as high as you want to go, this is what mx bikes have and run hapily on 95 octane.

seriously it is a quick cheap mod that you can feel.

look up these guys as well they know all about thundercats!
you will find many are running rons cleavers and topping 100kmh!

http://www.thundercatinflatable.com.au/forum/