amal carb on puch help

Tracy (a dude) /

I bought a puch with a amal carb a while back, and I just took it apart and cleaned the whole thing out to get the moped running again after it sat for almost a year. My problem is, I cant quite seem to get it calibrated right. My moped keeps bogging out when i try to give it gas at low speeds, but it has a crazy top end. so here are the questions:

ive fucked with the screws so much ive frustrated myself, and before I start damaging my ped i want to get it right. I thought i had it right one afternoon, but then the next day it was bogging out again.

1) are the two screws a) gas and air or b) gas/air and idle?

2) Is it right that it seems like the more I screw in these screws, the peds Idle speeds up, it seems counterintuitive that screwing them in would feed more instead of cutting off the flow

3) where i seem to get the best performace is with the bottom screw screwed in all the way, so that i can not screw it any further, and then adjusting the top screw to a certain point. this is where it boggs out the least, but really can that be right?

4) do i need to clean out the carb again or is there something else that may be contributing to the problem like an air leak? if so how would i diagnose it?

also it may be important that originally this carburator was working with a 70cc kit and now its running stock cylinder, but sean at myrons mopeds helped me adjust it to work before.

somebody please help me make my moped burn rubber like it did before i let it sit!!

and thanks so much you people in these forums are lifesavers

Re: amal carb on puch help

You might want to try to move the needle clip up or down a notch or two. I had one of those on a 70cc kit, now it is on a high torque 50cc. I had the same problem. Give it a try, and let us know if it helped. Brent

Re: amal carb on puch help

i am pretty sure one screw is idle and one is air mix but i think your problem might just be the size of the carb 17 mm is pretty big for a stock cylinder. there was another post recently about fuel and air velocity, and how a larger carb at lower speeds produces lower fuel air velocity and would explain your bogging

Re: amal carb on puch help

They didn't say what size Amal carb it was? I assumed it was 15mm, not 17mm. That's what I get for assuming.

I run a 15mm Amal on a ported high torque cylinder, and a 17mm Bing on one also. No problems with either. Check the needle setting, even if, just to rule it out. Brent

Re: amal carb on puch help

Tracy (a dude) /

so, if the screw is air mix, and when i screw it all the way in it seems to minimize the problem the most, that would imply that I am running lean? screwing it in should be cutting off air flow correct? This is the opposite, everybody has been telling me im running too rich! I dunno.

anyway lets assume this is my first time fucking with my carb, how do i adjust the needle clip?

Re: amal carb on puch help

Unscrew the top of the carb, where the throttle cable goes. Pull it straight up and out. The throttle cable is attached to this.That round piece is called the throttle slide. There is a spring in the middle, between throttle slide and the top. Hold the slide in one hand, and push the throttle cable down(into the slide) and it should release the cable from it's resting place. The skinny thing in the middle is the needle clip. It has 3 adjustment marks on it. Move the clip up or down a notch, in either direction, and put it back together, in reverse process. Adjust your air/fuel mixture screw , and your idle screw. You may need to do this a couple times to get it to tune correctly, so don't get discouraged. Brent

1202352027_needle_adjuster.jpg

Re: amal carb on puch help

Tracy (a dude) /

thanks a ton brent, I went out there and figured it out. The needle was in its lowest position, and I moved it up a notch. It totally helped the problem! I still bog very slightly, so im trying to figure out if i can adjust the air mix precisely to fix it, or maybe ill try bringing it up another notch. Thanks so much!

Re: amal carb on puch help

You're welcome, Tracy Like I said, it may take a couple times foolin' with it, to tune it correctly. Once you get it to the best it can be, and it still bogs, you may need a smaller jet. But it is probably torrerable now. Brent

Re: amal carb on puch help

I would say check for air leaks in the case and the base gasket and in the intake manifold and the the exhaust gasket. Those screws should not require that much thought to get the right setting. A small air leak wont really be noticed at high speed but at low speed makes a difference. I mean can you imagine this? Your friend or little brother comes and turns your screws. "whats this do?" Your like ARGGHH!!! It took my threee weeks to get them set right!!! No, they should be obvious as to the correct enough setting. But then again, I have spent hours and hours and hours tweeking similar screw settings or timing settings myself to try and achieve the perfect whateverness only to find later on that it was something dumb like that. Dont forget to check crank seals. They matter alot at idle and low rpm. Blow smoke in the intake at top dead center to find air leaks.

Re: amal carb on puch help

what jets to amal carbs take i got a 16 just sittin around and i'd like to use it on something

where do u get jets for these? to they cross ref any other carb brands?

will a local moto or scooter shop have these?

Re: amal carb on puch help

Elliot, here is where you can get Amal jets.

http://www.mopedshop.com/Moped-Jets-s/64.htm

Brent

Re: amal carb on puch help

holy crap those jets are $$

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