Needle in Puch MKII (Bing) Carb

I destroyed my original needle when I overhauled a badly neglected carb. from my Puch MK II.

I got a new needle for my carb, but I don't know which notch to attach the washer to (there are four notches).

I tried the second notch from the top. The moped runs great, but tops out at around 25MPH, which seems slow (although I don't know if it actually is for this moped because I never had it running until now).

It is a 1980 Puch MK II, 1.5 HP engine. Shouldn't it be going at least 30 MPH? Would the needle position make a difference? My intuition, which could be wrong, tells me that moving the needle up more, so that it is on a lower notch, would introduce more gas into the engine.

Thanks for your help.

Re: Needle in Puch MKII (Bing) Carb

the needle adjustment has nothing to do with the high end... when the throttle is wide open the needle is out of the picture.. and the Main jet supplies the fuel to the piston... the needle only regulates the amout of fuel flow to the engine in the low to middle speed ranges. The default setting is the second notch from the top.

I have an MK II as well and you need to try a few different jets to see which one has the best top end speed and then bactrack and fine tune the low/midrange speed by setting on the needle's notches. the second nothch from the top is the factory default and will probably work best if you have the correct size jet! :P

Re: Needle in Puch MKII (Bing) Carb

There are numerous reasons a bike's top speed might be a little low, from a slipping clutch or belt to dragging brakes to a clogged exhaust and everything in between. Rule them all out before you attempt to re-engineer the bike. Take advantage of the forum's Resources info like expected top speed might be in one of them.

Re: Needle in Puch MKII (Bing) Carb

Clutch is fine. Exhaust is clear.

As far as I know, the jet in the carb is the one that it came with out of the factory.

Does anyone know what the MK II 1.5 HP top speed is? I don't see it in any manual.

Re: Needle in Puch MKII (Bing) Carb

use the forum search function..

my first try with puch 1.5 hp top speed thread .. it seems to be more than 25mph.

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