Atomik 160cc 4 stroke hesitation at half to full throttle 1st and 2nd Gear

[zeph becks]

hey guys i'm new here so go easy, i have a 2015 Atomik 4-stroke 160cc with a Molkt carb it is stock from the factory, as far as i know. i have noticed since i bought it that it hesitates in 1st and 2nd past half throttle, low rpms are fine, and 3rd and 4th are good, i've tried turning the air screw in but cant find the right spot, and it doesn't really change, oh and my spark plug is black, so i changed it with a new one and after a few minutes of riding it was black. has anyone experienced this? is it possible for it to just not be adjusted right?
thanks!

 

[AntNZ]

If ya plug is black then it's more than likely running way too rich.
Have you done a proper plug chop??
Plenty of tutorials in the tech thread's on how to do proper plug chop if you are unsure.
good luck.

 

[zeph becks]

i haven't done a plug chop because i thought it could be a simple fix and at $10 a plug i thought i could try some other things first, yeah it's running wayy too rich and even when i pull the chock a tiny bit the bike dies, i always have to start it with it off, could it be that too much fuel is inside the float bowl?

 

[low_rb]

getting a better carb than the molkt willalso be a great advantage

 

[zeph becks]

what carb would you recommend?

 

[zeph becks]

'if it ain't broke don't fix it' would like to get this thing running properly its had barely any use 5 hours on the bike max

 

[low_rb]

A oko is a far better choice.

this thread might help you
http://www.miniriders.com/carby-and-tuning/24321-how-set-new-molkt-26mm-carby-jet-settings.html

 

[AntNZ]

A oko is a far better choice.

this thread might help you
http://www.miniriders.com/carby-and-tuning/24321-how-set-new-molkt-26mm-carby-jet-settings.html

I agree, I had a molkt on my lxr and it was s#&T from day 1!
I got a oko 26 flatslide and once jetted properly the power gains were impressive!

oko 26 and a 38-39 pilot and 102-105 main, should get it sorted.

 

[low_rb]

i cant exactly rember what jets are in my oko26 but i think

#40
#100
clip position 3

will need a rejet shortly as im putting a stock exhaust back on

 

[AntNZ]

i cant exactly rember what jets are in my oko26 but i think

#40
#100
clip position 3

will need a rejet shortly as im putting a stock exhaust back on

My stock z160ho is running 39 and 105, clip in middle.

my z160ho with v2 head is running 41 and 108, clip in middle.

both run sweet..oh and fuel/air screw is 1.5 turns out on both.

 

[low_rb]

My stock z160ho is running 39 and 105, clip in middle.

my z160ho with v2 head is running 41 and 108, clip in middle.

both run sweet..oh and fuel/air screw is 1.5 turns out on both.

mine is a z155ho with the v2 head, im in qld though so slightly different climate than NZ.
ive got a heap of jets, once i get the stock exhaust back on ill get it jetted spot on.

 

[Cordogs]

Molkt carbs are know to be nuisance carb, so the advice above is sound imo.

But we all know the excitement of a new bike so heres a few things to try while you wait for the oko to arrive.

Check for airleaks: start your bike get it idling, now spray some wd40 (or similar) all around the joining points of the inlet manifold, listen for the slightest drop in rpm. If there is you've got and air leak and you need to re-seat your carb or manifold.

If not.

Clean your carb jets there may be a blockage in your main jet. Remember just spraying a bit of carb cleaner and blowing it out with compressed air will not always clean out your jet. A small piece of wire will help here.

Before you start it clean your plug, a wire brush will make short work of it.

Give your bike a run and see if its fixed. If it is its ready for a quick tune.

Start your bike, get it warm, wind up the idle till about 2kish, now wind your mixture screw in (slowly) listen for the change in rpm. It should start to increase in rpm, keep "slowly" turning untill the rpm starts to drop off and then back it off just a touch.

This is a good place to start for your plug chops if you decide to do them.

If its not fixed wait for the Oko. :shoot:

 

[zeph becks]

Thanks for all your help guys! appreciate it!

 

[zeph becks]

oh also, what do you mean by 'clip in middle' 'clip on 2nd notch' etc?

 

[Cordogs]

Inside your carburettor there is a slide with a needle in it. On that needle there are little notches, on one of those notches is a little c-clip that holds the needle at a certain hight to regulate fuel intake. Raising/lowering it will change the intake of fuel....

 

[low_rb]

oh also, what do you mean by 'clip in middle' 'clip on 2nd notch' etc?

this pic explains the clip positions

 

[zeph becks]

I took the carburettor off and there was a build up of corrosion and dirt on the inside of the bowl where the surface had corroded, took the main jet out and blew through the hole that the jet sits in and it became un blocked, i can see why you would upgrade the carb because of the poor quality of the Molkt. Going to Noosa tomorrow so can't ride it until i get back, thanks for all your help! keen to see if it fixed the problem!

 

[Cordogs]

Hope you've got aircon mate, its pretty warm here atm and it's supposed to be 40 by Friday. :LolLolLolLol:

 

[low_rb]

Hope you've got aircon mate, its pretty warm here atm and it's supposed to be 40 by Friday. :LolLolLolLol:

Just getting to my comfort temperature

 

[zeph becks]

well that's better than Tassie's 'summer' when we get all 4 seasons in 1 day ahaha
keen as!