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Sorry for very late reply... been in Florida, playing :) The girly said 'No laptops allowed!'

I first noticed it on the new '06 Miata (FoMoCo) 2.0 engine. Oil pressure "sender" unit is an on/off switch, not pressure transducer. Gage readout is a total fabrication of the ECU. Disconnecting the "sender" generates a check engine light... after about a minute. Guys who put on analog gages report unreadibly low pressures warm at idle. My cousin found similar pressures on his '08 Mustang GT.

Oil pressure does not add value. It is the film, not the pressure, that holds the metal apart. Generating pressure costs power and mileage, so auto makers avoid it. PSI X Gallons per Minute / 1714 = Hydraulic horsepower consumed just moving oil around. And since that power isn't doing any work it ends up as heat added to the oil. So thin oil saves gas (to help meet CAFE standards) and helps performance and heat load slightly.

It all makes sense but is unsettling to us old school guys to see pressures that low. Low pressure was usually a symptom, not a cause, of worn engines. Just remember that the pressure itself doesn't do anything for you and in a carefully designed and machined engine it Should usually be no more than needed to operate hydraulic lifters and cam timing (which doesn't affect these bikes).

i'll have to research that and check some vehicles. i know on my jeeps that i've been working on and building for nearly 10years, that idle psi (warm) should be around 20ish +/-, and 40psi at speeds.

i have a hard time believing that any properly running car engine (and perhaps most bikes) would, sorry "should" be running anything less than around 10psi at idle, because some vehicles even have safeties build in, that it will shut down if the oil pressure drops below a certain psi, so it doesn't damage the engine.

yes, generally most test procedures for testing oil pressure is usually done at around 3,000 RPM (which for the 06 mazda 2.0L is: 49.0psi minimum at 3,000RPM), but that's because most transportation vehicles were designed to be moving, not to idle all day long, so the running pressure is almost more important than the idle pressure. generally speaking you only idle at stops, or maybe for a quick warmup.
 

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...testing oil pressure is usually done at around 3,000 RPM (which for the 06 mazda 2.0L is: 49.0psi minimum at 3,000RPM)...
Because that's when you Need the pressure. At idle there is little load on the bearings and the cam has returned to its base position. As long as oil continues to circulate and cover the bearings you are fine. As the fixed displacement oil pump speeds up more oil is pushed through the same passages thus increasing pressure. My point is that idle oil pressure is not that significant an indicator of engine health and is often lower than you might expect.
 

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I will not debate any of that except, are you sure the motor isn't designed for a higher octane fuel and again with all due respect, many are in agreement with you, however, the manual says something like "minimum" regarding octane. Am I wrong on that?

The minimum octane the bike will run well on is the octane to use the higher octane gas is more difficult to combust.

Adding water to your gas will raise it's octane rating or adding some other compound that makes it difficult to combust the gas like lead or ethanol. :twisted:
 

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I have a 08 c50 and like to ride the hiways. Is 75mph too much for the bike for 2--3 hrs at a time? or is this really beating on it, I'm 62 so this is most likely my last bike so I would like it to last.
I honestly don't know. I have always allowed plenty of time between point a and point b. I'm only 43 and I find myself enjoying the journey more and more.
 

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there are so many stories about speedo accuracy. here's one story that i heard ones.

they print the speedo faces off by roughly 5mph, to help reduce speeding, lower rpm, etc.. and to help reduce emissions because you're driving slower and using less gas.

a more accurate version (and what i truly believe) is this:

EVERY vehicle will have different accuracy simply because of unlimited variances of life. if the paper was in the printer off by just the slightest bit, now your speedo is of, combined with the printer head getting worn out, it started moving each print just a bit here and there until suddenly there is a difference of lets say 5mph between the first and last print. then when they go to cut it out, ever so slight difference is where they place the holes, cuts, slots to attach it to the plastic dash piece will move the speed lines, to where 3 different partially assembled speedos now have a 2mph variance. once you start screwing all the parts together, there is a little bit of play in the holes that the screws go through, so now the stem that the need rests on could be shifted to the left or the right ever so slightly. then when the indicator needle gets placed on the stem (or like when we replace our speedos with the webslinger face plates), if the stem rotated every so slightly, and/or the machine or person installing the needle doesn't always get it exact, etc..etc..

ALL of that will add up. and now you have 2 identical bikes build on the same day at the same plant by the same people, but they have different speedo accurateness.



oh and check this out......tire size WILL affect your speed reading. wait.....what??? you ALWAYS run the same size tire???
check this.
1)(exaggerated numbers for simplicity) when your tire is brand new, you have 1" deep thread. by the time you replace your tire, you have 1/4" deep thread.....guess what. that's 2 different size tires. so as your tire wears and changes size, so will your speed reading.
2)different manufacturer tires will also make a difference. i've seen LARGE offroad tires vary as much as 1" between the same size tire across different manufacturers.
3)higher tire pressure will make your tire taller. lower air pressure will make your tire shorter. don't believe me. go outside and measure from the floor to the top of your tire. now let ALL the air out of your tire. SEE the difference???

ever wonder why cops "generally" don't pull you over as long as you are doing LESS than 10mph over the posted speed limit??? i believe that part of it has to do with the variance in speedos across every vehicle. it has to be obvious that you are speeding.

What he said
 

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It's a great cruising bike so long as you have the touring package on it take care of the spark plugs and engine oil put decent tires on it and keep yourself as aerodynamic and as possible it can handle 80 85 no problem but mine seems to handle best at around those speeds on the freeway anyway any faster than that that bike just wasn't made for it.
 

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It's a great cruising bike so long as you have the touring package on it take care of the spark plugs and engine oil put decent tires on it and keep yourself as aerodynamic and as possible it can handle 80 85 no problem but mine seems to handle best at around those speeds on the freeway anyway any faster than that that bike just wasn't made for it.
Welcome from Kennesaw GA!

This is a 10 year old thread, btw.
 
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