We have 2 70cc Hensims that I'll call QuadA (one with problem) and QuadB (one that is running now). QuadA has about 12-15 hours on it. I have changed the oil at about 7 hours (2 rides ago) and put in 1/2 quart of 10W-30 and have changed the spark plug to an NGK CR7HSA (prior to our most recent ride).

Took it out the other day for my 6 year old to ride and it ran great as it always has, so far... He wrapped it up for the day and turned it off. I went to shuttle it back to my truck and it started for a few seconds and then died. Started it again and it died yet again. It hasn't started since then.

I checked for spark and don't have any both with new plug and old plug.

Here is what I have checked:

- Good fuel flow (not that it matters w/ no spark)
- Safety wrist thing and leash ? both have correct continuity
- Fuse - OK
- Battery - OK
- Air filter - it was dirty (since cleaned), but still no spark w/o air filter on there.
- No visible damage to wires
- looks like everything is hooked up
- Took from QuadA and put on QuadB the old spark plug and got spark, coil and spark plug wire, voltage regulator, and 2 "black boxes" that are close to the coil (I'd assume one is the remote kill because looks like antennae coming out of it) and ALL WORKED on QuadB.

I am at a loss - can you help me out on some things to check to get this running again?

Thanks,

Brian

 

When you put the quad A spark plug on Quad B did it start or didn't it. Not really sure what is going on maybe you might have a bad plug even the new brand tend to have a bad one every now and again. In all honesty if quad A's spark plug got you spark with quad B it seems like a plug problem. let me know how everything turns out. Im not sure how the chinese quads work but have worked on my share of small engines

later
Brett

 

Brett,

I didn't take the plug out of either machine, but took the OEM (Chinese) one and put in the spark plug on both machines and got a nice blue spark from QuadB and nothing from QuadA. He ran QuadA w/ the New spark plug for well over an hour straight with no problems before this happened.

I can try swapping the spark plugs if you think it may help.

Thanks!
Brian