Qt50 79 will idol but stalls as soon as I touch the throttle.

Michael Blennerhassett /

I'm only new to the game will I need a new gasket if I pull the carburettor apart? Do you think its a blocked jet or something else? I'm going to install a clear fuel line and fuel filter tomorrow.

Any feed back will be much appreciated.

Re: Qt50 79 will idol but stalls as soon as I touch the throttle.

Moped Lar (OFMC) /

If you're new to mopeds, Read Fred's Guide in the WIKI.....http://www.mopedarmy.com/wiki/Fred%27s_Guide

Re: Qt50 79 will idol but stalls as soon as I touch the throttle.

Yeah you just need to clean the carburetor.

Your main jet is clogged, 5 to 1 odds.

You don't need to buy anything besides a can of carb cleaner.

If its the first time you are doing it have a buddy there to make sure you don't leave anything out.

Luckily its a pretty easy carburetor to clean.

Just pull it off the bike. You can even leave the top on if you want. pull the bowl off, clean it out maybe with carb cleaner and a toothbrush, then unscrew the main jet.

You are going to need like a spun out brake cable or some kind of tiny wire to poke through the main jet.

There are plenty of videos on youtube.

Not sure if there are any QT50 specific videos but any Jog or Zuma carb is going to be almost the same thing.

Re: Qt50 79 will idol but stalls as soon as I touch the throttle.

Air leak. Possibly by the reed valve or carb.

Re: Qt50 79 will idol but stalls as soon as I touch the throttle.

Michael Blennerhassett /

Thank you so much for the advise! I will pull it apart today and post my findings.

Re: Qt50 79 will idol but stalls as soon as I touch the throttle.

the stock exhaust on these likes to get clogged up; eventually preventing it from running. i have had it happen on both of my yamaha Towny engines (same pipe).

while swapping out the fuel line, check both petcock positions for fuel flow

Re: Qt50 79 will idol but stalls as soon as I touch the throttle.

Michael Blennerhassett /

Ill have a look at that i just cleaned out the carb and am trying to get it running now so I'll take it off will it need a new gasket?

Ant tips for tuning the carb? I had it idling for 30 seconds then it stalled

Re: Qt50 79 will idol but stalls as soon as I touch the throttle.

Michael Blennerhassett /

I can't get it to run anyone got any settings for the idol and fuel air that works for them?

Re: Qt50 79 will idol but stalls as soon as I touch the throttle.

you got two screws there. one is idle rpm the other is mixture. if its on the side of the slide thats closer to the airbox its a air screw on the engine side of the slide of the carb, fuel mixture screw.

turn it to around 2 turns out. 1 1/2 to 2 turns out, from fully screwed in. and dont turn it in hard. just find it closed then unscrew 1 1/2 to 2 turns. start your bike. it should run. if it hits but doesnt idle, then screw in the idle rpm screw some. more in means higher slide, means more air faster speed, more, faster rpms. if it bottoms out pretty quick as you screw it in maybe its turned up too high. you can look at the back of the carb maybe with a flashlight and look downit to see where the slide is when you turn in the idle rpm screw.

should just be sorta cracked. and when it starts, you up the idle to sort of a high idle rpm. like itd be high for you if yo8u set the idle at that.

then adjust the mixture screw for the highest rpms.

just sort of keep your idle rpm the same thou as you do it and lower the rpms if it gets up too high while your adjusting it. keep it about the same.

once its set. lower idle to normal idle.

if it goes all the way in, and is best there, then the jets too big or small or its clogged.

clean or up or down jet. if its a fuel screw itll be too rich. air screw, itll be too lean of a jet. or probbaly clogged, maybe.

Re: Qt50 79 will idol but stalls as soon as I touch the throttle.

Clean the carb. air/fuel mix is 1 1/4- 1 1/2 turns out. idle is 2-3 turns out (edited)

Re: Qt50 79 will idol but stalls as soon as I touch the throttle.

Michael Blennerhassett /

Thank you everyone I got it going now have nice clean power! put in a inline filter now working on a air filter.

The oil line into the carby I'm afraid is not supplying a lot of oil I pulled it of when it was running thinking that it would be dripping out but nothing... there's oil in the line but it's not dripping out? Should it be or is it more of a vacuum thing?

Re: Qt50 79 will idol but stalls as soon as I touch the throttle.

Michael Blennerhassett /

Have it running smooth as silk but when I put the air filter on it slowly stalls... What are your thoughts on this. Do you think it's the jets? I'm really not sure

Any help would be grate

Re: Qt50 79 will idol but stalls as soon as I touch the throttle.

What air filter? stock?

Re: Qt50 79 will idol but stalls as soon as I touch the throttle.

Michael Blennerhassett /

The only part that was left of the stock air filter is the rubber gromett so i zip tied a peace of thin sponge to it iv tied breathing through it and it fells like no resistance at all but the Motor disagrees

Re: Qt50 79 will idol but stalls as soon as I touch the throttle.

Brent Bublitz /

Don't use sponge of foam directly over the inlet without a screen. When the foam starts drying out and crumbling it will suck chunks directly into the motor. Get a piece of screen.

Re: Qt50 79 will idol but stalls as soon as I touch the throttle.

Michael Blennerhassett /

Okay will do thanks for the heads up!

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