Carries on at 1/2 throttle

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Peter1230

Peter1230

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Joined
Jul 21, 2008
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Location
central coast NSW
Hey guys n girls,

Got my 155z engine last week
Was going heaps good on the weekend at gwandalan. From stock the carby (MOLKT) didnt need to be touched.
Now when i try go past 1/2 throttle is pops splutters and carries on.
Have done valves, and cleaned the carby, not sure as to what could be causing this.
Any ideas?

Oh and ive hit the odd false neutral, is this normal?
 
Peter1230 said:
Oh and ive hit the odd false neutral, is this normal?
Click to expand...

sounds like my bike
thump*140 said to me the missing gear thing is a dirty clucth or wrong oil like synthedic or semi synthedic or you need stiffer clucth springs

the half turn throttle thing might be the carby my bike used to do that to but on a jump or sertain part of the track but i don't know what that was it just when away after 5 services
 
Last edited:
sounds like carby acting up mate....
and i dont think false neutrals are normal... i ride with a mate thts got a 155z and its perfect

do your self a favor and pss the molkt carb off... its never gona run sweet without doing your head in first

and as for the gears.... try different oil... and sometimes moving the gear lever up a notch can help, just incase your not fully shifting it
 
Molkts are pretty bad carbys.. mine can be sweet one minute then totally un ride able the next....
 
Peter1230 said:
Hey guys n girls,

Got my 155z engine last week
Was going heaps good on the weekend at gwandalan. From stock the carby (MOLKT) didnt need to be touched.
Now when i try go past 1/2 throttle is pops splutters and carries on.
Have done valves, and cleaned the carby, not sure as to what could be causing this.
Any ideas?

Oh and ive hit the odd false neutral, is this normal?
Click to expand...
no false neutrals arent normal... i'd try an oil change, and perhaps a different sort of oil... did you put decent oil in it after you received the motor, or run it straight away with the crappy transport oil? please tell me you changed the crap transport stuff BEFORE you ran it in??
As for the coughing and spluttering, the symptoms would suggest your main jet is too big, or you need to adjust your needle clip... but you said it was running fine last weekend. If it was me, i'd turf the Molkt, get an OKO and be done with your woes..

motovert24 said:
sounds like my bike
thump*140 said to me the missing gear thing is a dirty clucth or wrong oil like synthedic or semi synthedic or you need stiffer clucth springs
Click to expand...

No no mate, i said the synthetic oil would be the reason your clutch is SLIPPING, not for the false neutrals...
 
yeh im running some shell helix plus.
I didnt even start it with the crappy oil.
With the neutrals i think it may just be it wearing in but it usually happens when i dont fully shift it, if u know what i mean
oh and i got absolutely no money left from this bike. I have spare jets. should i just drop a size in the main jet?
 
drop a size and see if it gets worse...
also have ya checked out the float level...because if i remember correctly some of these carbs had float level issues...maybe the engine is running out of fuel...

also does it only pop or does it shoot flames too
 
So i pulled the carby down, cleaned it and went to a 100 main jet from a 102 main jet. still no improvement.
As i had to use an adapter kit for the exhaust pipe i found the bolts didnt hold the pipe on very well. so i changed them back to the stock one and drilled out the holes that the exhaust mounts run through on my pipe to make the stock bolts fit, therefore holding the pipe on a whole lot better.
Still no improvement.
Wat else could it be?
Valves have been checked again and they are spot on. 0.003 intake and 0.004 exhaust.

Ideas please lol?
Not having any luck with this new engine at all.
 
Peter.... Have you tried adjusting the needle height yet???? generally if it's coughing and farting at mid throttle, it's needle jet related...
 
is that the adjustable clip in the "throttle cable area" if so i have lifted it all the way up to make the jetting leaner.?
 
Doesn't moving the needle up make it richer? As it lifts the needle and lets more fuel in?
 
lifting the clip..ie putting the clip on a higher notch up the needle lowers the needle...

peter have you sused out the float level in the bowl...if its too high or too low it will give issues
 
wait.
I used my brothers 26mm mikuni on it this arvo and the exact same thing happened.
My god this is getting hard to think of new problems it may be,
 
a dodgy seal around the exhaust manifold can do this, a common symptom of those crappy corrugated exhaust gaskets
 
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