why no bang?

[bear]

help me out here guys ive got very good spark and good fuel supply but the buggy will not crank up just keeps turning and turning its a gy6 in a dazon 150r was out riding sunday took a break and could never getr to start back up? all wires are connected, all fuel lines good, and all vacum lines check out so whats next?

[metalstudman1]

Have you tested the FEV?

[xlint89]

What's your compression? Hold the throttle wide open when testing.

[bear]

compression is strong but whats the fev?

[ckau]

FEV - Fuel Enrichment Valve. adds a bit of gas to richen the mix to aid in cold starts. Its' supossed to shut off after the motor has warmed but it's a electrical thing so it's not dependable and prone to cause problem at times. If the fev was at fault the motor should still fire up but run crappy due to a rich mixture. I would suggest checking valve lash. The valve setting tend to tighten up after a while and cause the problem you describe