Recent content by KartFab

You can get most realistic numbers from the off the shelf engine descriptions from NR racing

.039-.041”

Yerf dog runs a 7” driven. Run the sprocket on the outside of the jackshaft and relocate axle sprocket.

Compression on a compression release engine means nothing. look up summit racing compression ratio calculator.

Easy, set your valve lash to .002-.003” with feeler gauges.

If I remove governor, then I’m putting a cam in it. Stage 1 adds like 10-25% more hp, and a cam adds a crap ton more.

You should get a billet rod, advance timing by 4 degrees, and get an NR racing 280 cam, torque grind.

The gx390 Mano I have was stock stage 1 believe it or not. I upgraded a few things on it like 280 cam and connecting rod, but other than that it was stock. It actually was a very mild build.

Mild modified big block was floating the valves at 65 mph in under 300 ft, where higher stage small blocks were barely able to hit 55 mph in the 1/8th mile. This was at a drag race a few months ago.

this is about right but yours will make less because the carb is more restrictive than the stock appearing 24mm http://www.nrracing.com/product-p/eng-rac-420-pack2.htm

Last chance to win this mini bike by midnight tonight!!! https://teenlife.rallyup.com/minibike

Hello everyone, this is Grant. I have a little youtube channel and for those that follow the facebook page, muscle mini bike builds, you will recognize this beautiful mini bike as one of the top winners in the build off. I've had some recent life changes that have prompted me to give this mini...

2 stroke toro trimmer Was running ok then quit. Felt like it wasn’t revving out all the way. Would not restart. Put in fresh fuel would not start Carb cleaner sprayed directly in throttle body. Nothing Spark plug grounded and pulled could see spark Replaced spark plug would not start...

It has been a while since my last upload. For those that want to get into mini bike racing, this is the official "how to race mini bikes" video I put together. It has a few race tips, and a few guidelines for engine mods, but mostly gives a perspective from the Texas Outlaw Mini Bike racers...

So i may have ran over our neighbors grass a time or two, and my wife may have taken out our fencepost. This leads me to exhibit A. Winching the trailer up our weird, steep, and wonky driveway. I took some leftover 1.5"x3"x14ga square tubing from a previous table build for a customer (back...