Others running a 70cc reed Athena for Puch?

King Drunky JCams /

Hey all,

I've just installed a 70cc Athena reed kit onto my kickstart Korado E50 motor. I'm using a 18mm Mikuni carb.

The carb and intake both need sanding to make them fit together. I actually started a post about the tilting of the carb. Here's a link if you wanna see pics and read up on it...


I ordered a Simonini pipe, but for now I'm using my Techno Estoril....

I got the kit running yesterday despite the tilted carb. Seemed to run real well and have a bit of punch... The problem? A metal pinging type sound. Pretty damn loud I might add.

So I removed the head, and it and the piston showed no sign of touching, but to be safe, I installed another base gasket this morning.

It did not help.

Anybody have suggestions as to what it could be? The engine did not make that sound when stock...

Maybe a dumb question, but could it be the metal reed material I'm hearing flapping?

Do you think the 49cc Korado head could be causing it?

I posted in the buy/sell about wanted to purchase a 70cc high-comp head... we'll see.

Any suggestions as to what this metal clanging/pinging sound could be is much appreciated.


Re: Others running a 70cc reed Athena for Puch?

athenas have a lot of reed valve noise..

but, i just had this happen with a tccd kit install, the owner half-finished it, then didn't know what to do and gave it to me. when i got it together and fired it up there was a horrible tiniging noise. i pulled it all apart, nothing was hitting, and while putting in another base gasket, i noticed a wrist pin circlip sitting just inside the crankcase. It popped off when he took it off and he didnt bother looking for it.

i doubt justin campbell would make a mistake like that though.

Re: Others running a 70cc reed Athena for Puch?

) Cupermcnewbster ( /

metal athena reeds are notorious for breaking. Replace with carbon ASAP. Benji should have them from Boysen

Re: Others running a 70cc reed Athena for Puch?

The metal Athena reeds do make a pinging sound, but I can't judge if it's that by just your description. Can you make a video or something?

And like Zack said, replace em by carbon reeds ASAP, as they will surely break.

Re: Others running a 70cc reed Athena for Puch?

I had a athena kitted e50 magnum and it also was very noisy I always thought it was piston slap?? anyway, it never presented any problem other than the noise.

Re: Others running a 70cc reed Athena for Puch?

are they really that bad, or is it just when you slap on a 20 mm carb and rev it to 12k?

i should probably do that on my sachs athena too then, eh?

Re: Others running a 70cc reed Athena for Puch?

 GotSpark /

Yeah that noise you hear is the reedvalves, its a high pitched pinging noise.

And this kit in general is really loud out the intake and carb.

but yeah get those boyesen reeds, and check this out...


so, i cut the piston skirt after break in, and with a 21 phbg and estoril and 16/40 gearing topped out at around 50mph.

if you put the simonini on it, let me know how it works.

Re: Others running a 70cc reed Athena for Puch?

My athena makes no noise. Might the bottom of the piston be hitting the inside of the case? Can you feel anything when rotating the flywheel by hand?

Re: Others running a 70cc reed Athena for Puch?

I have one that I've been running for 2, maybe 3 years with the 17mm arreche carb and proma circuit pipe. never heard any noise from it at all.

Re: Others running a 70cc reed Athena for Puch?

mine kit sounds ok to me

Re: Others running a 70cc reed Athena for Puch?

i would check your clutch bell about that pinging noise.. the e50 on my cobra developed a ping only at idle- its a loud metal on metal noise- sounds horrible but isnt messing anything up too bad- from my observations thus far.

the simonini on an athena in my opinion is a bad idea.. ive been sitting with my magnum inactive for the longest time. i have everything set up. i had to cut off a gang of the cooling fins for the flange to fit.. and when i finally did that the angle was all off and it now it hits the shocks and im unable to mount it still. hopefully this next week i will be able to get assistance re welding it. at that point ill report on the performance.. i have it with a 19 phbg.

Re: Others running a 70cc reed Athena for Puch?

 GotSpark /

there are two different athena 70cc kits, could we be talking about different ones?

i think the easiest distinction is the reed block

one is a V shape with reeds on both sides

and the other is a Wedge shape with reeds on only one side


Re: Others running a 70cc reed Athena for Puch?

I had the same problem trying to mount the simonini on that kit. Shoots it straight into the shocks, and you have to cut the flange down to nothing to get it to fit inside the fins. I gave up, and bought an 80 metra the next week. :)

Re: Others running a 70cc reed Athena for Puch?

I have the one with the wedge shape with reeds on only one side.

Re: Others running a 70cc reed Athena for Puch?

King Drunky JCams /

Thanks for the replies guys. I was up til 3AM last night dicking with this. My list of what I've done and think I need to do seem neverending, so be prepared. I wrote everything down so I wouldn't lose track of what I've done...

The metal noise I'm searching for only occurs when there is compression. If you remove the spark plug, no sound at all. Remove the head, again, quiet. With compression, ping, ping, ping, ping, ping.... pretty freakin' loud. Like I can't hear the exhaust note well because all I hear is metal pinging.

I have TWO kickstart korado cdi motors with the needle bearing cranks. Both are super new with like 45 milea and 200 miles respectively. Both quiet and perfect with the stock setup.

My Athena kit has the reeds on both sides.

I will buy the carbon reeds today.

I want a 70cc head for this thing!

Anyway, here's what I've done so far:

I installed two base gaskets thinking the piston may be striking the head. Nope. Went back to the athena gasket and stayed...

Realized the head was on upside down. I never noticed the arrow on the head previously, so I flipped it and the gasket.

Next, I noticed that the piston skirt was barely striking the engine case on the down stroke like Colin suggested.

So, I went to my friend's shop and sanded down the piston skirt considerably, and notched the corners to make sure they would not hit the case anymore.

I took my spare kickstart korado motor to the shop also and port matched the engine case tot the Athena kit! Came out great and I heard and felt an immediate difference. WOW.

But still, a loud metal sound coming from the top end.


I should note that the metal sound gets louder as the engine warms up. It is loudest when going very slow or idleing. At speed it either quits making the sound, or I just can't hear it.

So I thought next of piston slap. Foward and backward... like a loose wrist pin.

I compared needle bearings and wrist pins (stock and athena provided) and found one needle bearing to have a bit more play than the other, so I went with the tighter of the two.

Still making a lound metal pinging sound that I just can't believe is the metal reeds.

The only thing left for me now is to remove the cylinder and piston, put them together and check to see how well the piston fits inside. I think the piston skirt is rattling up and down the cylinder.

Either way, this sucks.

I feel like I'm gonna break this 250 dollar kit everytime I run it up and down the street.

I took off work today to figure this shit out.

I'm going into the garage right now.

I hope my Simonini comes in today so I can smile about something moped related.

Talk to you all soon.

Re: Others running a 70cc reed Athena for Puch?

Yeah, my kstar makes the noise. It is the piston barely hitting the case at bdc. I'm going to tear the cases apart and fix it right. Shaving the piston will change your port timing. Also when heated up your piston might expand enough to hit again.

Re: Others running a 70cc reed Athena for Puch?

 GotSpark /

its the reeds making that sound.

for some reason they are really loud, even with the carbon fiber ones.

i just took that same kit that you have on a 100 mile ride WOT practically the whole time and its perfectly fine.

but i do understand that you want to make sure that its not hitting the case, but it's probably not.

Re: Others running a 70cc reed Athena for Puch?

 GotSpark /

oh and im running a 50 idle and 94 main jet, just in case you were wondering.

and for some reason, my kit gives me really wierd plug chops.

like half of the plug will be dark and the other side light.

and there really wasn't any variation in color when i was tuning it

(did a range from 98 to around 82 main and the chops cmae out very similar)

ive played with timing, point gap, plug gap, needle placement, and i just had to go by how it felt and ran because i couldnt tell from the plug.

it hasn't seized yet so hopefully im good.

Re: Others running a 70cc reed Athena for Puch?

i have the metal reeds and they dont ping.its more like a pitter patter sound ,i like the sound of my athena.

Re: Others running a 70cc reed Athena for Puch?

this is interesting. im going to install an athena kit on my motor. i felt the piston was very loose in the bore, so i mic'ed it at work. my particular kit has over 5 thousandths clearance. way out of spec for what it should be. i mic'ed a poliini today and it was 1.2 thou (slightly tight, perhaps the reason people seize them?) im seriously considering experimenting with knurling the piston to get the clearances within spec. if your piston jiggles somewhat freely in the bore, and the sound doesnt change pitch at all with the carbon reeds (they should sound slightly different id imagine) its possible there is just too much clearance in some athena kits. im assuming by your troubleshooting youve completely ruled out anything hitting anything else.

Re: Others running a 70cc reed Athena for Puch?

King Drunky JCams /

Yep, It can't be anything else than the piston is a bit loose in the cylinder.

I took it apart for the 20th time (not exagerating) and checked the play in the cylinder. There's not much, but enough I feel to make this noise.

As for shaving down the piston, I know I took enough off so it is not ever gonna hit the case again...

Frankly, I'm done searching for the noise... I'm just gonna run it as is. The piston shows no signs of damage, and it runs like a top, so I'm not arguing with it anymore.

I got my Simonini yesterday and it is totally rad.

I had to cut away two cooling fins and grind the rest of the fins on the bottom quite a bit to get it to fit. But it fits great now and performs and sounds awesome.

I just ordered a 70cc hi-comp head from Mopedshop.com.

Once that comes in I'd say I'm done working on the bike.

Next, is to strip the bike and have it powdercoated bright Ferrari (Rosso Corsa) red with chrome rims and gas tank.

Thanks for all the advice.

I'll post more pics soon.

Keep riding,


Re: Others running a 70cc reed Athena for Puch?

I've been researching Athena kits, and our wiki suggests that the reed-valve Athena 70cc kits come with an inferior, if not totally incorrect piston. They suggest replacing it. This might explain poor piston fitment in the bore. Read about it:


Re: Others running a 70cc reed Athena for Puch?

 GotSpark /

this is a picture of the right piston............

yeah i think mine came with like a metra piston or similar.

i heard there are a few kits that come with the wrong pistons,

i think its the right size because no problems for me in that are yet,

but just incase your wondering.


Re: Others running a 70cc reed Athena for Puch?

King Drunky JCams /

Benji at TreatsHQ asked me what letter was on the piston... it says "A" on it...

I'll see if he suggests a replacement. Thanks for posting the link... I wish I knew this before I got the kit...

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