300/440/550 87 stock js300

[slapshot58]

okay, so i got a js 300 for free two years ago, im starting to get that thing to handle it exactly how i want, i was wondering what else i can do to ''soup'' it up. quicker. funner. i wanna get hydro turf for it, get some sexy looking paint things like that. but performance wise, what can i do? any better carbs, piston and boreing recomendations.

btw, last summer i blew somthing in the electrical and it sat for the year somthing caused it to have no spark, and it wasnt worth putting the money into parts so, up until today! i bought a used motor that ran. put the new motor in in less then an hour then got out on that lake!!! ran perfect!
ancake:ancake:ancake::fest06::fest06::fest06::biggthumpup::biggthumpup::biggthumpup::biggthumpup::biggthumpup::biggthumpup::biggthumpup::biggthumpup::biggthumpup::biggthumpup::biggthumpup::fest06:

 

[Jetpilot106]

you can do a few things to them but you will never really make it that fast.u need to just swap a 440+ in it.If you cant do that then you could get things like a pipe,filter,carb jetting,water box mod or custom waterbox.

 

[Suprx125]

Kerkers & Mariner both make a pipe for the JS300 & you can usually find them on ebay. Many guys claim these are good for 10hp alone on the 300. My buddy has a Mariner on his & I'd have to agree. You can slap a 38sbn carb on as well which will also wake it up. Other things you can do are mill the head, boyesen reeds, port the cylinder, good stainless prop, & install a 2nd pisser to dry out the stock exhaust a bit if you intend to keep it. Check out Group K's website as they have several mod's they can do to these. Make sure you block off the oil injection & pre-mix the fuel if you havn't done so already.

 

[GrantWarden]

You might consider a flow control valve or modding your stock pipe (or both) if you take that route.