Stupid diy power mods 6.5hp hondaclone

[Chrisvdw]

I am thinking about replacing the engine with a 420cc but i want to have some fun with the old one first... im on a budget of nothing so im thinking about porting and polishing the intake and exhaust skimming the head for more compression and maybe welding the cam lobes bigger... maybe even some jetfuel or nitros
I would appreciate any advice or ideas. Thanks

 

[karl]

Hold my beer, ill show you a really stupid DIY power mod I did last night

It does work, more smoke on the "dyno", until you throttle the blower up too much and the boost blows the gas out the bowl.

Some mods and Ill be on my way to mad HP

 

[HONEYBADGERFTW]

If you're just messing around with it to see what HP you can make free/cheap, try grinding the crankshaft a little, port intake ( don't polish ), port and polish exhaust, cut off every other blade on the fan, drill out the main jet in carb a little, gut the exhaust manifold or just cut off everything above the pipe...early in the morning so might have missed something obvious or misspoke about something lol

 

[mckutzy]

Heres a start...
https://affordablegokarts.com/pages/performance-basics

 

[J.S.@SMS]

Don't forget about removing the governor. And I agree with everything in the article that mckutzy posted (as well as everything posted in the previous posts) Except the upgraded valve springs. If you upgrade the valve springs to 18lb springs (next step up) the valvetrain will be capable of 6500 rpm, whereas the rod is only capable of about 6000 rpm. So long story short, stock rod + 18 lb springs = blown rod, hole in block, and typically a demolished camshaft. And you also have to worry about the flywheel flying apart. So I don't recommend upgraded springs, But it's your engine, so do what you want want to do.

And if you don't want to modify the camshaft, I'd recommend these:
https://www.arcracing.com/dj-1100-stamped-ratio-rocker-1-3-sold-individually/
They increase the valve lift without modifying the cam.