MOPED ARMY

62 did it. Still a mystery as to what’s caused my sudden need for a down jet. Runs nice and strong now. Beat my dads revel in a race lol.

It can be, about 20-30 degrees f air temp on a highly tuned bike will change the jetting one size, but usually stockish bikes won't be so touchy.

Sometimes a plug fouling will make you 4 stroke, so you will be tuned 'perfect' one day but a bit rich and then a few miles later the plug will soot up and now you're four stroking.

Oh this was you with the wrong mounted circuit pipe? Yeah the air leak you will get from the pipe being mounted wrong will fuck you up. If I were you I'd wait to ride it until you can mount it right but I was in your shoes once and back then I would have 100% sent that shit

ARGH! Started four stroking again. I hope that’s what this is at least. It kind of sounds like a popping, brr sound, sort of like if I were to let off the throttle slowly at high speed, but it only hits in at WOT top speed. I’m gonna check my plug to see if it’s fouled, this is very annoying. I’ll check for air leaks again. My float bowl gasket is mostly toast, doesn’t leak much, but do you think that that needs to be airtight? Could that be my issue? Stock 12 bing btw.

At a 60, bike makes power, doesn’t four stroke at top end WOT. Throttle up to WOT also feels better. Doesn’t lean bog either. Engines up to temp, will throw in a fresh plug and do a plug chop minus chop.

It's a ZA50, so nope.

It looks fine to me, but I've seen a source of random 4-stroking be inhaling trans oil. Keep an eye on it, if it randomly 4-strokes again, check the trans level.

Looks a good colour. Now it is down to fine tuning of the needle first, rather than a jet change.

Well, after my first ever moped seizure, and like 15 bucks worth of piston rings, some carb cleaner, and way more work than I want to do for a long long time, it’s running again. Stuck a 64 on there for safety. Discovered (or created) an air leak at the top of my carb. Could very likely be the issue. I’ll see if I start four stroking at 64 but won’t down jet. I’ll replace that thin gasket at some point and see if that helps. Either way runs well, and most importantly isn’t stuck.

If your running a really over size carb for the bike just 10 degrees will make a difference.

Like the guy early said it really don’t mess with stock bikes ..

I had a 72cc bike that stock had a 16mm carb ..after stage 5 porting and a spanny etc I got to a 30mm carb that ran great in Florida on the normal hot sticky mid day 85 to 95 and 80% humidity with 105 main ,,and a dark brown plug .., but if I rode out at 8am and it’s 72degrees … ish the plug would turn light light tan to gray in the middle .. the 110 main would fix it ,,,, then 60 degree morning 115 main or it would lock up ..

I REALLY don’t no your term 4 stroking ?

As in what the bikes doing ??

If you are running a to bigger jet for the air temperature the plug will be really dark brown and at the end of each gear if you hold it out to get maximum REVS it will feel like it’s pulling back and sound bad ,, same if your a no gear bike but at max speed .. if this is what you mean … as it 4 strokes as you say … roll the throttle back just like .1/16 to 1/4 and if it clears even picks up a little speed … your to fat ..on the main by a little bit .FOR that day that air temp ..

Yep 2 cycles …. Like a women …. A hot one that knows it ..

hard to get it just right … but when you do

( oh yer baby ) !!!!!

Yes, I two would like to know about this stage 5 porting 🤔.