Motor problems NZ

[Jimidixon]

Hi there everyone. This is my first post here on motoredbikes and I have a few questions I hope someone can answer.

I've bought myself a 66cc engine kit here in NewZealand which I think is similar to the zbox kit. Its all on and working well apart from one thing...

When I rev the engine at a standstill it revs strong and fast, but when I'm riding it the engine seems to girgle at around 20mph. Its really anoying as I can feel it has so much to give. I have however chopped half the baffles out , and changed the sparkplug to the equivilant ngk and lengthened the exhaust shaft slighty.

"Help"

 

[BoltsMissing]

Welcome to MBc

All the best

BoltsM.

It does not end at the spark plug, you may have to try another higher qaulity copper plug lead and a right angle NGK plug cap.
Not sure what you have done to air filter, looks cool though.

There is much to trial and error, I think mainly the exhaust port is a good starting point, if you notice the gaskets don't match the engine's port hole, so try shaping out the gasket.
There is another trick you may like to try with the exhaust if it leaks often thereafter.
Try this exhaust "heat sink" idea, use spring washers to fill in the space so it has some flex. as the metals expand due to heat.
Then there are some good tips on Zbox web site on the carby jets.

 

[Jimidixon]

Great I'll try that. I did notice the shape of the exhaust port on the motor is a different shape to the exhaust. Weather thats making a difference I dont know.

Thanks again