Moorron
|
 posted on 6/8/07 at 01:35 PM |
|
|
am i thick?
Hi guys me again.
Still don’t know what i am doing so some help would be nice.
CBR1000F burning oil. Lots, 400ml in 100 miles.
I did a compression test the other day and posted the results on here. 95 psi on all 4 cylinders. Someone on here said I was doing it wrong and by god
they were right, I had to make an adaptor to fit the pressure gauge into the smaller bike spark plug hole. Didn’t realize the gauge has a one way
valve at the base, so my adaptor was creating a void to fill and hence gave me the wrong reading. It wasn’t all wasted time as it shows that all the
cylinders are producing the same pressure.
My stupid questions for today are:
1: If the pressures are all the same is it likely that the oil loss is due to the piston rings? In other words does an engine wear as even as mine has
shown?
2: If so can I assume it’s not the piston rings and must be 1 or more valve oil seals?
3: can I replace the valve oil seals with the head still on the car?
I don’t mind replacing all the valve seals as there cheap, but if I replace them when not needed:-
4: would this cause me more troubles other than wasting my money?
5: i am going to sort the cam chain tensioner too as its not working, can you clean these up or is it better to get a new one?
Many thanks guys, main reason is I want to order the parts so they are here before I start limiting the time the car is off the road.
Andy.
Sorry about my spelling, im an engineer and only work in numbers.
|
|
|
|
|
mookaloid
|
| posted on 6/8/07 at 01:40 PM |
|
|
how does this losing oil show itself?
Is there a lot of blue smoke coming out of the exhaust? does it happen on power or on overrun?
It may be cheaper to get an other S/H motor if the problem is piston rings (smoke when power on) or if it is valve stem oil seals (smoke on overrun)
then it might be cost effective to replace them
More info might help
Cheers
Mark
"That thing you're thinking - it wont be that."
|
|
|
nick205
|
| posted on 6/8/07 at 02:25 PM |
|
|
When you re-did the compression test, what readings did ou get?
That might also halp identify if the oil loss is top end or bottom end related.
One sign of top end (valve stem seal) wear can be lots of smoke on start up. This happens when oil has drained down the valve stem into the cylinder
and is then burnt off on start up.
Not sure about bike engines, but most car engine valve stem seals can be change with the head in situ using a special tool to stop the valve from
dropping whilst the valve spring is released. Personally I would rather take the head off and check the condition of the engine more thoroughly and
replace any other gaskets and seals - e.g. head gasket which, if knackered, may be contributing to your problems.
|
|
|
Moorron
|
| posted on 6/8/07 at 02:52 PM |
|
|
cheers for the replys.
when warmed up if i stop the car and rev it hard to its max rpm, the smoke apears right at the point i get to max rpm. its close call if its as i let
off the gogo pedal or just before.
the colour of the smoke is white not blue.
havent done a recheck of the compression as i need to buy the right tester.
It doesnt use much oil if i keep the revs down and drive like miss daisy.
Sorry about my spelling, im an engineer and only work in numbers.
|
|
|
martin1973
|
| posted on 6/8/07 at 05:31 PM |
|
|
compression test sound ok to me.
was that with the trottle full open?
try wet testing with a little oil
martin
|
|
|
mad-butcher
|
| posted on 6/8/07 at 06:00 PM |
|
|
plugs are the tell tale for most ills in an engine,
what colour are the plugs if it's running right they should be a nice chocolate brown,
running rich sooty black
burning oil wet black.
Back page of haynes manuals generally have pictures of what I mean.
Easy way is to do a plug chop.
difficult to explain, but run motor up to full power under load, disengage clutch at the exact same time kill the engine, do not release cluch untill
you've stopped. remove plugs and check, this will tell you how the engine was run at that exact point in time.
tony
|
|
|
