spark but no spark?!?!

Whats up everyone? I need help! I cant get the spark on my "hog" to jump on the spark plug. I got power to the plug but its just not strong enough to jump. If i grab the plug and ground it out itll give me a jolt but just wont spark on the plug. I got new points ( gapped correctly ), ignition coil is good, and so is the plug. Im stumped and dont know what to do next. Please help! Im dying to get this thing to run and its the only thing stopping me right now. Thank ya much for any help!


Re: spark but no spark?!?!

Brandon E /

Try a new spark plug wire. Only thing i can think of if everything else is good. How fast are you turning the engine over when you check the spark?

spark plug

How do you know the plug is good?

Is it new?

If not... buy a new one and try it.

Spark plugs on 2 strokes can get "fouled' and still look pretty good ... but will not spark.

My experience is that if the spark plug wire will send a jolt halfway up your arm... that the ignition system is all good ... and the spark plug is just bad.

Re: spark plug

bosch platinum ... enough said.

Re: spark plug

The spark plug is new. but im not getting a jolt up my arm, only thru my hand.Im also giving the bike a pretty hard kick when i check it. I tested the plug in a mower and it worked fine. Any other suggestions?? Thanks!!

Re: spark plug

you should be able to check for spark WITHOUT the spark plug in. that's how we check for spark most of time. that way you can instantly tell if it's something other than the plug. if, as you say, the plug is fine, check w/o the plug for spark on your moped.

if it sparks, it's the plug. if not, begin troubleshooting to see what's wrong on that end.

and just because the plug is new doesn't mean it's good. be sure you're using the proper plug. i highly recommend bosch platinum series.

Re: spark plug

Hi, allways remember new dont mean good...the condersor could be bad or weak, and some points have a film over the contact area from sitting, clean as in Freds Repair post. Doug D.

Re: spark plug


Re: spark plug

Jon Dalton /

I had the same problem and it turned out to be the cap. Real cheap to replace.

Re: spark but no spark?!?!

Dont mean to sound like a fool but what cap?? I was also thinking of my condensor, which is mounted right on the coil. Is that replceable or do i need a whole new coil? Thanks soo much for the help so far yous are great! ~Matt

Re: spark but no spark?!?!

Hi, Matt...the "cap" is the bakolite gizmo that pushes on the spark plug, a few peds use car type and not the cap type...Doug D.

Re: spark but no spark?!?!

Another question.......Is ond hard push on the pedals enough to start a ped or do you have to pedal your ass off to start it??

Re: spark but no spark?!?!

you shouldn't have to "pedal your ass off" to start it. some start on just one kick, others might take a few pedals. but if it takes too much to start, you might have (in no particular order):

(a) bad compression

(b) the moped was sitting for too long and may need some help, play w/ the choke

(c) electrical problems

(d) timing

(e) no spark

that's all i can think of right now. someone else can probably do better. look for fred's guide in the forums. it's a super long step-by-step guide for troubleshooting. use that.

also, in your next posts give more detail. type of moped, exact things you've done or didn't do, everything. it makes it easier for people to help you.

Re: spark but no spark?!?!

Hi Matt, It depends on the ped, I have 1 Tomos that starts with 1 push, another one that takes 2, and about 3 AMF that take 35 ft to start...there no telling.

Re: spark but no spark?!?!

Matt... the first thing I would do to get spark is to make sure the spark plug cap is not loose or broken.

By the way... where did your coil and wire and cap come from?... I remember you were going to substitute one from something else...that could be a problem.

If they are good... then I would first clean the points... because if there is ANY dirt.. even a speck... you will have no spark.

As far as starting...The PA50 has a cable operated compression release mechanism built into the cylinder head.. if it is leaking your ped will not start.

I have removed the pedals on mine and push start it with the release pulled in.. I have to push it about 5 feet...then release the comp. release lever.

Re: spark but no spark?!?!

I got a used coil( part numbers matched) but the wire was too shot and the cap was shot. I used a copper core wire to extend it and soldered it so i know i have a good splice. The cap i replaced with the same type used on a car plug. Is that kind of cap no good for that??

Re: spark but no spark?!?!

Well it is too late now... But you should have tested the 'new' coil before modifying it.

And it would have been far better to have re mounted it closer to the head (say.. on the front frame downtube).. then it was to cut and splice it.

Did you wrap it in insulating tape well enough?

And the part numbers out of a Honda book are not the same if it is a different length.

But now that you have done that... The next thing I would try (you may have already) to run a wire straight to the coil from the points.

Then I would try another coil/wire (borrow it maybe?) to eliminate your modified one as a problem.

Or perhaps take your coil off and try it on a running ped and see if it still runs.

Re: spark but no spark?!?!

Wow! thanks soo much for all the help so far. Today as i was trying to figure all this out i suddenly got a spark on my plug. as fast as it came it left =( So im pretty sure i got it down to a wiring, problem. The ped was in really bad shape when i got it and i had to rewire it, which im 99.999% positive i did right. Does all the wiring have to be in place in order for it to start or can i just run the coil wire straight to the points and forget about the other 3 wires on the motor. Then when its running ill worry about the lights and other crap. Thanks again you have all been great!!! ~MATT

Re: spark but no spark?!?!

You can run the 1 wire straight from the points to the coil... No other wires necessary.

That is the easiest way to eliminate other stuff from messing up your testing.

One thing though.... If you get it started you won't be able to shut it off unless you unplug something.

Re: spark but no spark?!?!

I find plugging the holes in your air box will kill an engine safely when you have no other way. I think there are a few Decepticons who have no other way to shut off their peds.


Re: spark but no spark?!?!

Hey thanks guys!! Im headdin out to the garage now and see if i can get the thing to run. Ill write back and tell you how i made out, thanks again!! ~Matt

I GOT IT TO RUN!!!......but......

Shes runnin!!!!! wooooooooohooooooooooo!!!!!!!! But i cant get the motor to stay running with out the choke on. Any ideas???

Re: I GOT IT TO RUN!!!......but......

Chris Robertson /

Here's the stuff I'd recommend you check if your moped only runs with the choke on (in order I'd try them):

For information on procedure refer to the message "How To Fix Your Moped".

1. Make sure you have fresh gas (less than two or three months old),

2. Make sure your exhaust isn't plugged up. Have you cleaned it?

3. Make sure that the carburetor is on the engine tightly and has a good seal.

4. Clean the carburetor. Make sure to clean the jets very well.

5. Make sure there isn't any rust in your tank (make sure you have a fuel filter while you're at it --if you don't just buy a cheap in-line filter (about $2) at an auto parts store and hook it up between the fuel tank and the engine).

6. If you have a decompression valve on the cylinder head (somewhere near the spark plug), make sure it isn't loose or dirty.

7. Check the timing. Use the cigarette paper technique to set it.

8. Make sure you have good compression. This is best checked with a compression gauge --borrow or buy one. You want to have at least 100psi compression (some of my peds are at the 160psi mark) --the higher the better. If you have crappy compression, watch the engine while it's running for leaks.

May the Force be with you.

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