Puchmoped won't spark

[lewis s]

Hi all, i have just purchased a Puch moped that has'nt been run for 30 years. The fuel side of the engine i can deal with, but at the moment i am having trouble getting a spark.

The bike has a magneto and no battery. I have tried a new spark plug, cleaning the points and adjusting to the correct setting and checking all the electrical connections i can find. The magnets still feel quite strong, and what puzzles me the most is that if i hold the plug against the block as i pedal (good old fashioned pedal start ) i get a small electric shock through my fingers, so it is producing some current.

What else can i check, or what else might be the problem?

I can get photos of any part of the bike if this may help?

[Steve_D]

Can't be sure but I suspect there are some contact breakers inside the flywheel. Yes the magneto produces the spark but it needs points to get the timing right.

Mopeds I had as a lad you needed to pull the flywheel, which was on a taper + woodruff key, to get at the points which in your case I suspect have seized on the pivot pin.

Steve

[Pumaracing]

Steve_D said:

Can't be sure but I suspect there are some contact breakers inside the flywheel. Yes the magneto produces the spark but it needs points to get the timing right.

Mopeds I had as a lad you needed to pull the flywheel, which was on a taper + woodruff key, to get at the points which in your case I suspect have seized on the pivot pin.

Steve

Given that he said he'd cleaned and adjusted them one suspects not!

Anyway it's possibly the condenser's failed which wouldn't be surprising given its age. You might also check that where the points are supposed to be insulated from the backplate that they still are. Finally check the resistance of the HT lead.

[Boosted LS1]

If it won't spark then use a match. That'll get the job done

[Steve_D]

Pumaracing said:

....Given that he said he'd cleaned and adjusted them one suspects not!......

Missed that bit...too early in the morning.

Steve

[macdeb]

Which one [bit off topic] I had a Puch moped in '75 when I was 16. A 3 speed, yellow with chrome tank, wish I had the phucker now.

[blitzracing]

http://science.howstuffworks.com/question375.htm

More to the point it has two coils, the primary (thick wires) that grounds through the points, and a finer wire secondry wound around the same magnetic core. One end of this secondry coil goes to ground, and the other to the plug. I would think if the wiring to the points is good, then the other ground end of the coils needs checking, but its possible over 30 year that some of the insulation has broken down on the secondry windings, so its shorting out, and the output voltage will suffer. As suggested its probibly worth pulling the magnetic rotor off and sripping and cleaning the various connections.

[blitzracing]

macdeb]Which one [bit off topic said:

I had a Puch moped in '75 when I was 16. A 3 speed, yellow with chrome tank, wish I had the phucker now.

Dogs nuts that one VZ50,(crap 3 speed gearbox however) only surpassed by the Puch Grand prix with a 60 mph top speed.

[macdeb]

blitzracing said:

macdeb]Which one [bit off topic said:

I had a Puch moped in '75 when I was 16. A 3 speed, yellow with chrome tank, wish I had the phucker now.

Dogs nuts that one VZ50,(crap 3 speed gearbox however) only surpassed by the Puch Grand prix with a 60 mph top speed.

Yup, the gearbox used to take some getting used to from 1st to 2nd and I swear my arm had to move through 90 degees to perfect it. I also remember the Grand Prix, though I was 17 then and moved on to a Honda 250 K2 [gold/white] you could ride one then on 'L' plates! Had problems with the 'points' on that.

[lewis s]

blitzracing said:

macdeb]Which one [bit off topic said:

I had a Puch moped in '75 when I was 16. A 3 speed, yellow with chrome tank, wish I had the phucker now.

Dogs nuts that one VZ50,(crap 3 speed gearbox however) only surpassed by the Puch Grand prix with a 60 mph top speed.

Indeed it is a VZ50, yellow with chrome tank and crappy 3 speed box. It has been hand painted in the past so i am going to go for the full resto

I can get some pics of it later if anybody is interested, but bear in mind i have only had it a week though and am just concentrating on getting it running

[Del 203]

blitzracing said:

macdeb]Which one [bit off topic said:

I had a Puch moped in '75 when I was 16. A 3 speed, yellow with chrome tank, wish I had the phucker now.

Dogs nuts that one VZ50,(crap 3 speed gearbox however) only surpassed by the Puch Grand prix with a 60 mph top speed.

fk me what a thread (sorry op cant help) i had a Monza

[Simon Says]

After 30 years Lewis no spark may be the least of your problems a jellied up carb is typical and the other is dried out crankshaft seals causing lack of primary compression and massive airleaks don't mean to piss on your desert but it is a possibility i take it you are using a fresh plug?

[lewis s]

Well if i can get a spark at least then i can just work from there

Some pics incase anybody is interested:







PS does anybody know if this is the E50 engine, as i keep seeing it mentioned but am not sure if it is the same as what i have on mine.

Thanks.

Lewis

Edited by lewis s on Saturday 13th February 23:08

[macdeb]

Cool. Seem to remember you had to press the 'pedals' backwards for the rear brake. I added an extra pedal on mine so both feet were level when riding and not 'push-bike' like. Them were the days I'm jealous

[Pumaracing]

I must say it does bring back happy memories of my Suzuki AP50 back in 1976/77. That was a damn good little bike which would do 50 mph at a push although the brakes weren't up to much. It got me to school 20 miles each way through everything including packed snow without missing a beat. I remember sitting on a main road one winter's morning waiting for a gap in the traffic to turn right into the road leading to the school and when the gap appeared I let the clutch out gently and the back wheel just span the road was so icy. God knows what I was thinking riding a bike in conditions like that but I survived somehow.

Hope you get it running anyway.

[blitzracing]

If the crank seals do leak, then Wynns (I think anyway) does an oil additive that softens the seals and brings them back to life, so its worth a go. The biggest problem with the VZ was a shaft in the gearbox that used to wear badly. One of the gear cogs used to slide onto some locking pegs on this main shaft, but these would wear out (quite quickly) and it would jump out of gear all the time. It used to cost about £40 for this shaft (in 1976- that hurt) but I dont remember it being a problem changing it for us spotty 16 year olds with basic tools and a hammer. Engine wise, I think there were 2 basic types, one with a fan cowling and forced cooling and 2 speed box, and the VZ with its big fins and three speed. I dont remember there being any significant power increase with the VZ over the 2 speed version, it just looked faster, 26-27-28-29- yes 30 mph.

Edited by blitzracing on Monday 15th February 12:51

[Pumaracing]

I found something online about Puch mopeds that if any of the light bulbs are blown, or even the horn not working, then it might not spark. Must be some damn weird wiring to cause that but worth a look.

http://www.mopedsonline.com/m-o-l/trouble_shooting...

[Magic919]

Takes me back. I had the M50 Sport as my second moped. Fitted an expansion chamber :-)

[Pumaracing]

Slightly related I was down in the village (Chalfont St Peter) a couple of years ago shopping and there was an absolutely mint 1976 Yamaha RD250 parked up in the precinct. Electric blue, coffin tank and it gleamed. The engine was jet black and the chrome was pristine. Even the exhausts looked original and mint. Near as dammit concourse condition barring a slightly suspect seat cover which looked like a replacement. I ogled it for a while hoping the owner would return so I could chat but no one did.

I never owned one although I had a Suzuki GT250 for a while but back in the day that Yam was the tool to have. Seeing one over 30 years old in such perfect nick made my day. I bet it's worth a few bob nowadays too. Can't be many of those left.

[Del 203]

stop mentioning the bikes i had


Mine was white with black wheels





Lewis have you got it running yet ? Nothing like the smell of 2-stroke in the morning

Edited by Del 203 on Tuesday 16th February 10:06