help with performance?

#4
I told him that because i have tried modifying the 3 horses and you do all of those mods and it will leave you performing like a stock 5 horse.
 

Ratbike

Active Member
#5
I don't mean to be an as# but get a 5 horse.
Unfortunately he's right. I tried to find perf parts for a 3hp and really couldn't find anything. By the time you get it built you will have more in it than buying a 5hp:hammer:Good luck !! But it would be cool to do it ,,,also very original too. Don't remember anyone doing it here:gunsmilie: Being the under dog is always fun!!!
 
#6
The thing is... on a lot of the smaller to medium frame bikes the 3 horse motors just look better then the bigger 5 horse IMO.
Go for it ! They are great motors.
 
#8
Go for it #1 .20 over on the piston #2 18 lbs on the valve springs #3 aluminium flywheel
#4 mill the head and thin head gasket #5 index the plug to the exaust port #6 air cleaner
a must and #7 all seals gaskets and take off the govener raely easy make sure you get all the touqe specs also vary important
Ive done this to 2 3 1/2 hp B&S motors vary good results oh dont forget a throtle kit fom BMI karts
for the mill work use Mason Henjes vary good guy to work with and cheep too
MRH Performance Karting 712-274-6822
you will have to do some digging around for a master rebuild kit but with a .20 over piston i cant remember were i got my kit ill look in my notes
remember opinions are like buttholes eveyone got one its a good leaning curve
 
Last edited:
#10
Id go with the 5 horse, but,

I think a small header, no governor, new aircleaner and a few other things might help the little 3 pony breathe better and therefore produce a little more power, the 5 horse would be vastly cheaper if you want EXTREME performance, because custom machining for rods and cams will cost you a nice pretty penny,

try searching "3 horse mods" here or on 4cylcle.com There are people that have done it, and a few that have produced some very impressive dyno results
 
Top