spark plug

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golo-golo

golo-golo

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hi,just break in a new motor with ngk spark plug installed but it just fire up for 15mins then engine down,ive checked that the firing end is fouled and wet,can i use gasoline to clean it up?
 
If the plug was wet you're running too rich. Did you reset the Carb to factory settings? They're rarely set correctly from the factory.
 
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Pollishman said:
If the plug was wet you're running too rich. Did you reset the Carb to factory settings? They're rarely set correctly from the factory.
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hi, i did nothing on the carb since i unpack the motor out of box!its walbro 668 and fire up first time today.
 
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golo-golo said:
hi, i did nothing on the carb since i unpack the motor out of box!its walbro 668 and fire up first time today.
Click to expand...
lean out the carb a bit till it stays running,
your gonna have to play with the carb settings till it's broken in, then you tune to get the best performance out of it
 
It may be an idea to check the LOW, HIGH needle settings.
Factory default is 1 1/4 LOW, 1 3/8 HIGH.
Don't forget that each engine is slightly different, and manufacturing tolerances mean that this is not an 'exact science' but it may be worth seeing just what your carb is set on.

These settings appear to be slightly rich for a standard engine, but need to be set richer for a tuned engine.

Simply COUNT the turns screwing CLOCKWISE into the carburettor - BE GENTLE!! - until you reach some resistance, and don't force it. This is fully CLOSED. Then simply screw out.
For reference and curiosity, count how much you had to screw in anyway, to check out how it was set.

Al.

Al.
 
hi,follow you guys info and the motor fire up and go on break in process, i left the motor runs the first tank fuel at neutral throttle, when the fuel almost run out, the motor goes HIGHER RPM suddenly so i shut it down for safe! isnt it normal to have such situation when fuel runs out?
 
Pollishman said:
Yes, that's normal. How many times have you ran it, and for how long each time?

!
Click to expand...

BE A LITTLE CAREFUL !!!
YES, as they say, it's normal, as when the fuel's leaning out (running out) the revs will rise ... BUT .... and it should only be for a short while but if the revs rise higher than the take-up of the clutch, IT WILL MOVE FORWARDS ..

Take a little care where you store it if idling. It's better to use a little throttle anyway and not simply leave at idle ..... many theories on that one.

Al.
 
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just break in the first tank and i shut it down for safe when the above situation occur.if thats normal,how many tanks should i run for break-in stage before tuning the motor in good performace?
 
atom3624 said:
BE A LITTLE CAREFUL !!!
YES, as they say, it's normal, as when the fuel's leaning out (running out) the revs will rise ... BUT .... and it should only be for a short while but if the revs rise higher than the take-up of the clutch, IT WILL MOVE FORWARDS ..

Take a little care where you store it if idling. It's better to use a little throttle anyway and not simply leave at idle ..... many theories on that one.

Al.
Click to expand...

atom, got your point,thanks.
 
just break in the first tank and i shut it down for safe when the above situation occur.if thats normal,how many tanks should i run for break-in stage before tuning the motor in good performace?
 
golo-golo said:
just break in the first tank and i shut it down for safe when the above situation occur.if thats normal,how many tanks should i run for break-in stage before tuning the motor in good performace?
Click to expand...

Nearly everyone will give you a different answer.
One guy in America found an official quote from a manufacturer.

Some will blast 'full bore' from the start. Remember, these are lightly tuned weed-whacker engines, and nobody breaks them in!!

Before firing, I would carefully check the carb settings - 1 1/4 LOW, 1 3/8 HIGH - and then fire up.

Most will fire up, leave 10-20 seconds to see if it's running steadily, gently rev a few times LIGHTLY then start driving gently up and down - 'heat cycle' the engine.
Probably best 2 or 3 times of 30 minutes if you're in Hong Kong with high ambient temperatures, letting it cool for 10 minutes in-between.
Don't go above 1/4 to 1/3 throttle to start.
Don't keep at a fixed setting either.
After the first tank, check all bolts - engine mounting, cylinder head, manifold, exhaust, etc., - are still tight. If not, TIGHTEN THEM - not SUPER tight, but tight enough.
Run the second tank - a wisp of smoke is nice - too much and spluttering is a bit too rich. A standard engine make require the carburettor leaning off. Leave it quite rich - cooler running, better lubrication - to start.
During the second, you can certainly use half throttle - I was already testing full!!
If you've already run the 3rd tank, then no problem I would guess - check bolts, tune up.
If it's been running quite rich until now:
1. It's probably better to change the spark plug.
2. Clean the filter while you're at it.
3. Now check other threads, and tune it up.

Once tuned it's not like nitro. It will generally be performing near-perfect all of the time now, with very little required - no fiddling with the tuning each time the sun comes out, or when it's overcast ...

HappyDays.com !!

Al.
 
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