motorbyclist
27th September 2008, 17:59
so my little brother came out on his hornet today (been on it less than a month) for the waitakere loop, and by the end of it there was oil pissing everywhere, "from the engine".
got home (where the gear lever decided to fall off half way down the driveway apparently due to bolt not being tight enough) and couldn't find a leak anywhere, and as there was oil everywhere we were a bit worried.
then we noticed an open pipe leading from the airbox, which had oil dripping from it....
long story short:
when the previous owner, my other younger brother, had last done an oil change, he never actually changed it; he just "topped it up"
sure enough, we drained two litres of oil before it returned to a normal level, and expect to drain a bit more once it's cooled down properly
so over the last month the airbox has been slowly filling with oil until it's come pissing out this random hose...
this random hose is something from the previous previous owner... we bought this bike from a dealer with less than 20k kms on it.... and this is something a dealer mechanic should have noticed:
the oil overflow/breather hose from a road bike normally goes from crank case into the airbox, where the oil will sit and vapours be sucked into carbies for burning. this way we don't need a seperate filter on the breather hose as the air filter is there.
to drain the airbox there is a cup shaped hose thing which you remove. some dork has gone and replaced this with a open hose.
why is this bad? for the last 5000km+ the bike has been taking in air from near the ground, straight into the airbox without passing through the air filter
- so all sorts of shit/dust/grit/sand has been sucked straight into the carbies/valves/piston/valves again, and while in the combustion chamber they can help create carbon/coke deposits
also, a motor with twice the recommended amount of oil is a BAD thing. the counterweights on the crankshaft etc will hit the oil, which isn't good in itself, but that will churn and aerate the oil, turning it into froth.
oil pumps aren't too effective at pumping froth, and froth, being mostly air, isn't a very good lubricant.
so what can we learn from this?
a hot engine has a lot of oil up in the head(s), so don't check the oil on a hot motor until it's had sufficient time to drain. (i've mucked that one up too)
screw the dipstick in by hand for christ's sake - we had to use pliers to open this one
hold the bike level!
if a hose is blocked, DO NOT replace it with an open one (and viceversa)
don't get your air filter wet. clean it with compressed air. this one is rooted, and feels like someone put air filter lube on it too.
what does this mean for the hornet?
it hasn't had an oil change in well over a year, so that will be done
new oil filter too
it needs a new air filter, the old one is soaked with oil and full of dirt anyway... i suspect the only reason the bike didn't cut out was the air bypassing the filter via the "custom intake hose"
fortunately, the good old honda doesn't seem to be suffering
/rant
got home (where the gear lever decided to fall off half way down the driveway apparently due to bolt not being tight enough) and couldn't find a leak anywhere, and as there was oil everywhere we were a bit worried.
then we noticed an open pipe leading from the airbox, which had oil dripping from it....
long story short:
when the previous owner, my other younger brother, had last done an oil change, he never actually changed it; he just "topped it up"
sure enough, we drained two litres of oil before it returned to a normal level, and expect to drain a bit more once it's cooled down properly
so over the last month the airbox has been slowly filling with oil until it's come pissing out this random hose...
this random hose is something from the previous previous owner... we bought this bike from a dealer with less than 20k kms on it.... and this is something a dealer mechanic should have noticed:
the oil overflow/breather hose from a road bike normally goes from crank case into the airbox, where the oil will sit and vapours be sucked into carbies for burning. this way we don't need a seperate filter on the breather hose as the air filter is there.
to drain the airbox there is a cup shaped hose thing which you remove. some dork has gone and replaced this with a open hose.
why is this bad? for the last 5000km+ the bike has been taking in air from near the ground, straight into the airbox without passing through the air filter
- so all sorts of shit/dust/grit/sand has been sucked straight into the carbies/valves/piston/valves again, and while in the combustion chamber they can help create carbon/coke deposits
also, a motor with twice the recommended amount of oil is a BAD thing. the counterweights on the crankshaft etc will hit the oil, which isn't good in itself, but that will churn and aerate the oil, turning it into froth.
oil pumps aren't too effective at pumping froth, and froth, being mostly air, isn't a very good lubricant.
so what can we learn from this?
a hot engine has a lot of oil up in the head(s), so don't check the oil on a hot motor until it's had sufficient time to drain. (i've mucked that one up too)
screw the dipstick in by hand for christ's sake - we had to use pliers to open this one
hold the bike level!
if a hose is blocked, DO NOT replace it with an open one (and viceversa)
don't get your air filter wet. clean it with compressed air. this one is rooted, and feels like someone put air filter lube on it too.
what does this mean for the hornet?
it hasn't had an oil change in well over a year, so that will be done
new oil filter too
it needs a new air filter, the old one is soaked with oil and full of dirt anyway... i suspect the only reason the bike didn't cut out was the air bypassing the filter via the "custom intake hose"
fortunately, the good old honda doesn't seem to be suffering
/rant