Suzuki Volusia Forum banner
41 - 60 of 68 Posts

·
Premium Member
Joined
·
27,214 Posts
So according to theory around here cranks and rods should only wipe out at low RPM...hmm not my experience. It only takes 5PSI to float the crank and rods on a Harley motor. As RPMs go up so do other forces. It takes higher oil pressure to keep parts from making contact. If this wasn't the case, oil pumps would be designed to maintain constant pressure, and they can be. Harley racing oil pumps as well as many automotive racing oil pumps holds at least 30PSI no matter what RPMs the engine is running because they don't want lag on the oil pressure when the RPMs jump.
 

·
Premium Member
Joined
·
27,214 Posts
I should add the reason for low oil pressure at idle in an air cooled motor is to keep more oil in the pan longer so it has a greater opportunity to cool vs being heated up in the heads. lower oil pressure = less oil circulating = lower oil temp at idle when no air is blowing over the motor. <br>
 

·
Registered
Joined
·
1,945 Posts
Speedo error:

My GPS speed versus indicated on the speedo is consistently ~10% regardless of speed.

50 indicated is 44-45 on the GPS.

67 indicated is 60 on the GPS.

80 indicated is just over 70 on the GPS.

At 90 indicated the whole bike is shakin' so hard I'm afraid to take my eyeballs off the road to look at the GPS!

YMMV.


.
Many make the mistake of thinking GPS reading are instantaneous GPS readings are average speeds over the past little bit or so. To get an accurate GPS reading you have to hold a constant speed for a surprisingly long period of time. Try going to 90 first or whatever speed you are comfortable with and then compare your speedo to the GPS as you slow down. Be sure to hold your speed for quite a while, You get more accurate readings this way.
 

·
Registered
Joined
·
663 Posts
Don't know about the bike, but I'd wear ATG as I know my skin won't take it at that speed. Read an interesting article the other night in MCN about what ATG means to different people. To me, it includes all the usual stuff + textile pants.
 

·
Registered
Joined
·
403 Posts
I have an 07 C50. I have 45000+ miles on it, with numerous 800+ mile days on the bike on the superslab doing 80+ mph for 12 hours- no problems. I do change the oil and rear wheel fluid every 1000-1500 miles.
 

·
Registered
Joined
·
354 Posts
Some interesting ideas running around here...

Many modern engines, especially small high performance auto engines, idle at no more than 5psi oil pressure, and with very thin oil. Modern oils have higher specs than we had just ten years ago. Some car mfgs (Ford and Mazda for sure) have the ECU jigger with the oil gauge to keep it from reading low at idle and generating worry and service calls. Don't lug an engine or set the idle lower than mfg spec.

Octane rating refers to gasoline's resistance to spontaneous detonation. High octane is harder to light. High octane fuel allows engines tuned to use it to run higher compression ratios, more advanced timing, leaner mixtures, more boost, and at higher temperatures, but contains no extra energy in itself (well, a little but not enough to make any difference). If your engine does not knock on regular (our bikes don't have knock sensors to adjust the timing, so you would hear it) there is no conceivable performance advantage to using premium... and it will burn incompletely and be harder to start in cold weather.

There is, however, a noticeable advantage to corn-free gas. Ethenol is added to fuel for the extra oxygen it brings to late in the combustion cycle. It helps reduce pollution. It has a much lower energy density than gasoline so you will burn more to make the same power. Modern engines are designed for the stuff and will run forever on it but you will get more power and better mileage if you can find pure gas (usually only available away from cities and during the cool months... Oh, and at race tracks)
 

·
Premium Member
Joined
·
574 Posts
Many make the mistake of thinking GPS reading are instantaneous GPS readings are average speeds over the past little bit or so. To get an accurate GPS reading you have to hold a constant speed for a surprisingly long period of time. Try going to 90 first or whatever speed you are comfortable with and then compare your speedo to the GPS as you slow down. Be sure to hold your speed for quite a while, You get more accurate readings this way.
I certainly hope that you did not think that I was zooming to a speed and then reporting that as accurate.

When on the urban freeways here in SA I use my Gman throttle lock to maintain speed with the traffic flow. What I reported is a long average speed and is accurate.

.
 
  • Like
Reactions: jpboyes

·
Premium Member
Joined
·
3,046 Posts
HalfFast, you said it better thanI could.
May I add, ethanol causes meat prices to rise, attacks aluminum & rubber (leading to many boat fires) and absorbs water like a sponge resulting in varnish (clogged jets & injectors). We pay for a product that has almost no benefits and lowers fuel mileage.
http://www.boatus.com/seaworthy/fueltest.asp

http://www.boattest.com/resources/view_News.aspx?NewsID=3465

Something I found that will dissolve the varnish is Power Tune. Available from marine dealerships for about $10.
 

·
Premium Member
Joined
·
6,301 Posts
Every Spring I end up taking out my carb to clean it, no matter what I put in the tank for the Winter. It's habit now. I always said if there was ever a race at a rally for either removing the front wheel for the Speedo sensor replacement or removing and cleaning the carb I would win. :)
 

·
Administrator
Joined
·
29,816 Posts
Hold it! So when I run my engine at lower rpms cruising in 5th instead of 4th I am harming my engine? More so than the lower rpms are extending its life and saving gas? I have no position here, I am just trying to understand. And if so, is this true for automobile engines as well?
Well, all v-twins take a beating at low speed, the less balanced or if they are offset, the worse this is. Its really not something to worry about, unless you are lugging the engine.

If you have good motor oil in your C50 and you are maintaining the valve train, operating at higher RPMs than you think is good for the engine.
 

·
Premium Member
Joined
·
27,214 Posts
Some interesting ideas running around here...

Many modern engines, especially small high performance auto engines, idle at no more than 5psi oil pressure, and with very thin oil. Modern oils have higher specs than we had just ten years ago. Some car mfgs (Ford and Mazda for sure) have the ECU jigger with the oil gauge to keep it from reading low at idle and generating worry and service calls. Don't lug an engine or set the idle lower than mfg spec.

Octane rating refers to gasoline's resistance to spontaneous detonation. High octane is harder to light. High octane fuel allows engines tuned to use it to run higher compression ratios, more advanced timing, leaner mixtures, more boost, and at higher temperatures, but contains no extra energy in itself (well, a little but not enough to make any difference). If your engine does not knock on regular (our bikes don't have knock sensors to adjust the timing, so you would hear it) there is no conceivable performance advantage to using premium... and it will burn incompletely and be harder to start in cold weather.

There is, however, a noticeable advantage to corn-free gas. Ethenol is added to fuel for the extra oxygen it brings to late in the combustion cycle. It helps reduce pollution. It has a much lower energy density than gasoline so you will burn more to make the same power. Modern engines are designed for the stuff and will run forever on it but you will get more power and better mileage if you can find pure gas (usually only available away from cities and during the cool months... Oh, and at race tracks)
I'm not saying it does not exist but I have never seen 5 PSI in a modern motor even running 0-20 weight. Which motors? I know the reason for low idle pressure in an air cooled motor and in particular Harley which did it on purpose, but what is the purpose in a modern engine? The tolerances are so tight there is no need for gimmicks to make the oil pressure look higher than it is. I'm not saying it does not exist, I just haven't seen it and I'm curious since you put it out there.
 

·
Registered
Joined
·
189 Posts
cali-c50----my experience with he c50 exactly!!! I also have a fully loaded and accessorized 2007 Nomad 1600 and while bigger and faster--i'm not sure it's a better bike. C50 is much easier to handle-----so I've decided to sell the Nomad and keep the C50(I am getting on--LOL)
 

·
Registered
Joined
·
354 Posts
I'm not saying it does not exist but I have never seen 5 PSI in a modern motor even running 0-20 weight. Which motors? I know the reason for low idle pressure in an air cooled motor and in particular Harley which did it on purpose, but what is the purpose in a modern engine? The tolerances are so tight there is no need for gimmicks to make the oil pressure look higher than it is. I'm not saying it does not exist, I just haven't seen it and I'm curious since you put it out there.
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).
 

·
Registered
Joined
·
3,328 Posts
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.
properly maintained and in good operating condition, it can handle more.

i can tell you for a fact that i've done in the range of 30-60 minutes at nearly 100mph. (empty highway and pack of corvettes as rabbits. you don't get that opportunity very often. LOL)

my wife and me have done 2-3hours at an average of 90mph side by side coming home from vacations.

and i've done countless of hours at all speeds below that. LOL
 

·
Registered
Joined
·
3,328 Posts
See now I swear mine is dead on. I have ridden (word?) along cars with digital display speedometers and they were in sync with my speedo. Yet, I have heard on this forum that they are 5mph generous.
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.
 

·
Registered
Joined
·
3,328 Posts
I don't know what you guys are talking about, "the whole bike is shakin' so hard I'm afraid to take my eyeballs off the road to look at the GPS!" and "squirrely" my bike is sure footed and smooth (for a V-Twin) at all speeds at least up to 110 MPH actual speed and I would not consider the bike to be underpowered for an 800 its actually good on power (its not a sportbike) also at higher speeds the vibs are actually smoother than at 65-70. If the bike is shakin' or squirrley then something mechanical is wrong, out of true wheels or wheel balance is bad, cupped tires, front shocks (replace oil) or bad springs, rear shock worn or improperly adjusted for weight, worn swingarm bushings steerig head has play worn bearings also wheeel bearing that are worn can cause problems like shakes and squirrleyness. Get you bikes looked at by a professional before its too late...
x1,000
 

·
Registered
Joined
·
3,328 Posts
Every Spring I end up taking out my carb to clean it, no matter what I put in the tank for the Winter. It's habit now. I always said if there was ever a race at a rally for either removing the front wheel for the Speedo sensor replacement or removing and cleaning the carb I would win. :)
x2. sucks having your bike top out at 80mph downhill. LOL carb cleaning and valve adjustment EVERY SPRING for me.
 
41 - 60 of 68 Posts
Top