No spark after ~2min

Puch E50

HPI mini rotor ignition

push button kill switch

stock Puch wire block connector for all wiring, non of those clamps

resistor plug boot


first time this happened, it ran over 4 miles an all of a sudden wouldnt do over 25mph (normally hits 45mph)

4 miles has now reduced to about 50 yards and no firing at all

testing (recent):

takes a few pulls to start, kinda weak but fires up

tested with a timing light after it quits -> no spark

stator replaced (new) => no change

swapped in a different cdi box => no change


do HT coils ever go bad?

its not running long enough to get hot.

i havent tried disconnecting the kill switch...i hope thats not it

i cant really check the CDI box(s) with a multimeter... maybe they're both bad

motor was completely rebuilt, im pretending thats not causing any new problems

im not sure i ever checked the spark plug

ok i think i have a pretty good list of things to check, yall are welcome to tell me im an idiot and list off things i forgot

Re: No spark after ~2min

Well,you always replace the spark plug first. What about that resistor cap?

Re: No spark after ~2min

Guess ill start with new plug, plug boot, plug cable and check for airleaks with carb cleaner if I can get it to idle.

Re: No spark after ~2min

Yes . HT coils do go bad . Not often , but , it does happen .

And , they don't have to be hot when it happens .

You might try removing the resistor from the plug cap and replace it with a piece of solid wire . Your system should be good with only a resistor plug or HT wire , as generally only 5K µ resistance is required .

Re: No spark after ~2min

Have new NGK B8HS spark plugs. Was looking at the boot and discovered 2 things, its not a resistor boot and the spark plug cable was kinda loose coming out the the HT coil, I tightened it at least 2 revolutions. So imma gap a new plug and test again... will post results.

Should I also test with a 5K µ resistance boot (I have one)? I know theres been a great debate on moped army over this topic. Some cdis need resistance, people claim HPI doesn't; fiik

Re: No spark after ~2min

You should clip about 3/8" off the end of the HT wire that was in the coil . If it was that loose , I suspect a bit of corrosion there . Also inspect the coil 'screw' that accepts the HT wire for any corrosion .

If the HT wire is resistor type , it should be enough resistance for any system .

But , it shouldn't hurt to try the resistor boot if you usually have good spark .

Want to post in this forum? We'd love to have you join the discussion, but first:

Login or Create Account