DeathProof
Member
if you constantly ran it rich at break in ratio 24:1 instead of lean after 2 tanks 40-50:1 what would happen? if it runs awesome at break in stage whats the difference just leaving it?
Fuel Mixture What would happen if you constantly ran your engine rich like at break in ratio?
- Thread starter DeathProof
- Start date
Fabian
Well-Known Member
Nothing would happen, if the carburettor is jetted correctly.
Because of the loads i tow and virtually 100% duty cycle placed on the engine, i run a 20:1 oil fuel ratio and have been doing so since the word go, about 2 years ago.
"""ALL""" my engines have had a consistent problem with bottom end bearing failure, but this was largely attributed to the standard CDI giving an ever increasing spark advance with rpm.
Since fitting the Jaguar CDI, i have not had any more big end bearing failures; in my case, the only reason why all 7 engines failed.
From what i understand the newer engines use a crowded roller bearing setup for the big end which is significantly more reliable than the previous caged needle roller bearing.
Because of the loads i tow and virtually 100% duty cycle placed on the engine, i run a 20:1 oil fuel ratio and have been doing so since the word go, about 2 years ago.
"""ALL""" my engines have had a consistent problem with bottom end bearing failure, but this was largely attributed to the standard CDI giving an ever increasing spark advance with rpm.
Since fitting the Jaguar CDI, i have not had any more big end bearing failures; in my case, the only reason why all 7 engines failed.
From what i understand the newer engines use a crowded roller bearing setup for the big end which is significantly more reliable than the previous caged needle roller bearing.
ddesens
Member
I don't think you would have a problem. You might have to go through spark plugs a little quicker. You might have more smoke out the exhaust than most. You will definitely have more oil dripping/spraying out your exhaust.
Fabian
Well-Known Member
Oh yes, there "will", make that """WILL""" be more oil dripping/spraying out the exhaust and more oil on the operator and more oil on the mechanicals.
As the cooling system on these engines is fixed i.e. pegged to the surface area available for heat transfer, the only other method of heat extraction is through thermal transfer to unburnt excess oil, hence when riding in shorts, your legs will get attacked by scalding droplets of hot oil and socks, shoes and jeans will essentially become a dirty rag.
20:1 isn't necessary if the engine is lightly loaded; rarely seeing high duty cycle i.e. putt, putting around.
In such a scenario, you could easily get away with 40:1, even 50:1 if gently cruising about, using cheap 2-stroke mineral oil.
My situation though is perfectly suited to cheap 2-stroke oil because i'm using it for heat extraction, not for any extra lubrication.
As the cooling system on these engines is fixed i.e. pegged to the surface area available for heat transfer, the only other method of heat extraction is through thermal transfer to unburnt excess oil, hence when riding in shorts, your legs will get attacked by scalding droplets of hot oil and socks, shoes and jeans will essentially become a dirty rag.
20:1 isn't necessary if the engine is lightly loaded; rarely seeing high duty cycle i.e. putt, putting around.
In such a scenario, you could easily get away with 40:1, even 50:1 if gently cruising about, using cheap 2-stroke mineral oil.
My situation though is perfectly suited to cheap 2-stroke oil because i'm using it for heat extraction, not for any extra lubrication.
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DeathProof
Member
thanks guys i appreciate the feed back! 
tooljunkie
Member
the only thing i would add is the soot from the rich mixture may clog the screen in the exhaust,it does it on chainsaws and trimmers,so i would expect to clean or replace the muffler from time to time.
this is especially true if synthetics intended for leaner ratios (optimol) are mixed rich.
this is especially true if synthetics intended for leaner ratios (optimol) are mixed rich.
Fabian
Well-Known Member
@ tooljunkie
I would have thought the same thing about the muffler clogging up at 20:1 but in two and a bit years, i've never had the need to clean it out, though my engine mostly runs at 100% duty cycle.
I would have thought the same thing about the muffler clogging up at 20:1 but in two and a bit years, i've never had the need to clean it out, though my engine mostly runs at 100% duty cycle.
Cavi Mike
Member
Fouls the plug constantly and leaves a puddle of oil under your exhaust. I keep mine rich because I'm more concerned with longevity than performance.
andrew5826
New Member
On my goped motors I mix 91 octane with redline at 32:1, heat cycle it for 10 mins not letting it idle too much and just let it rip wot most of the time. All my motors look brand new inside and are hitting 14.5k+. The reason you run the motor hard is so that more pressure gets behind the piston ring and seats it better thus more power.
LaLongueCarabine
New Member
Wow, that's what I remember we used to do with our 125-175cc back in the day.
We never had a problem with these engines and we ran them hard.
Does it even make sense to go with the super lean mixes that some say are OK?
We never had a problem with these engines and we ran them hard.
Does it even make sense to go with the super lean mixes that some say are OK?
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