Author Topic: 76 550 top gear rev problem  (Read 6624 times)

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Offline TwoTired

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Re: 76 550 top gear rev problem
« Reply #75 on: May 06, 2017, 11:52:47 AM »
A foam filter functions on the principle of the "tortured path".  Yeah kinda made up that term.  But it applies pretty well.

The filter's base filtering rating is related to the size of the cell bubbles that comprise the foam membrane.  Generally nothing can get past unless it fits through tiny holes.  Most bugs, plant, and dirt flakes will pile up on the outside.  This, of course, is better than having the engine ingest them.

On to the next level of particulate matter; finer abrasive dust/sand, etc.
You'll note that seeing through the filter membrane is difficult at best.  This is because the open cell foam structure does not reveal line of sight pathways.  And this is the reliant principle by which all foam filters operate.  Air cannot take a straight through pathway through the filter membrane.  It has to twist and turn to get to the other side.  The mass of the dirt particles is heavier than air molecules, and so have a difficult time changing direction of travel.  The particles then collide with the foam cell structure and hopefully stick.  This is where the oil comes in.  Particles are more readily trapped by an oil whetted adhesive surface.

Of note, is that foam filters are what is termed "statistical" filters rather than absolute filters.  The foam pathways are bigger than almost all dust particles.  But, they statistically trap most particles due to oil's adhesive properties, and the "tortured path" they are forced to take through the membrane.  Since the oil is a functional part of the foam filter system, a thin but pervasive coat throughout the membrane is desired.  But, note, there is no guarantee that it will trap ALL particles which are smaller than the size of the cells in the structure.

Also, they are not install and forget.  The dirt and oil must be cleaned out periodically in relation to whatever dusty environments you operate within.  Dirty foam can dislodge the trapped particles with shock and/or oil's adhesive fatigue.  Then it dumps the oiled globs of dirt into the intake for ingestion.  Not a good thing.  So, it is best to stay on top of the cleaning cycles.

In the environment I'm used to (CA bay area), we have low particulate laden air.  So, I've been using the UNI foam filter inside the stock air box now for decades.  I've noted that summer use requires more frequent filter cleaning cycles than in winter months.

With my move to Arizona, I will have to revisit my foam cleaning schedule and perhaps return to the more expensive Paper filters, which guarantee finer particle collection at the expense of more frequent replacement schedules, due to not being able to effectively clean them after some use.

Lastly,  the foam DOES deteriorate with age, at which point bits of foam, clean or dirty, pass through the engine cylinder on it's way to the exhaust with varying degrees of abrasiveness.   This occurs with UNI foam whether its a POD type or the air box element.  This is best found during a clean/re-oil process.  Rather than years of in situ use.  In my experience, 10-15 years is the service life, with proper cleaning solvents and correct oil use.

Cheers,
Lloyd... (SOHC4 #11 Original Mail List)
72 500, 74 550, 75 550K, 75 550F, 76 550F, 77 550F X2, 78 550K, 77 750F X2, 78 750F, 79CX500, 85 700SC, GL1100

Those that learn from history are doomed to repeat it by those that don't learn from history.

Offline turboed13b

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Re: 76 550 top gear rev problem
« Reply #76 on: May 06, 2017, 02:26:05 PM »
It doesn't really matter what kind of intake you run once you jet it correctly they will all run the same. A lot of people on here are hardcore antipod and I am not sure why because they work perfectly fine.

With that said you can't run the unis in the rain you will have a bad time.

Offline FIREBLADE74

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Re: 76 550 top gear rev problem
« Reply #77 on: May 06, 2017, 03:26:55 PM »
TT, wonderful explanation, thanks!!

Turboed, I almost never get caught in the rain knock on wood. As for anypods working I have to disagree even with proper jetting I was having problems with the regular pods and based on TT explanations I think it's the tortured air path that put me in the game!!!
06 CBR1000RR, 76 CB550

Offline turboed13b

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Re: 76 550 top gear rev problem
« Reply #78 on: May 06, 2017, 09:08:05 PM »
I have plenty of bikes working on pods and run just as smooth as stock. It takes a while to learn how to tune and many people give up way too quickly.

Offline calj737

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Re: 76 550 top gear rev problem
« Reply #79 on: May 07, 2017, 04:15:13 AM »
I have plenty of bikes working on pods and run just as smooth as stock. It takes a while to learn how to tune and many people give up way too quickly.
I too believe it's possible to get a bike to run on pods, BUT, only a dyno proves that to be true. And I have yet to see anyone provide a dyno graph to prove pods run as well as, or better than stock air boxes. So, take it with a grain of salt that a bike is running "as well as". Because the very nature of the change is well documented to negatively effect the performance versus stock induction.
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"Of all tyrannies, a tyranny sincerely exercised for the good of it's victim may be the most oppressive. It may be better to live under robber barons than under omnipotent moral busybodies. The robber baron's cruelty may sometimes sleep, his cupidity may at some point be satiated, but those who torment us for our own good will torment us without end for they do so with the approval of their own conscience." - C.S. Lewis

Offline FIREBLADE74

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Re: 76 550 top gear rev problem
« Reply #80 on: May 07, 2017, 03:13:57 PM »
Geezus! Only getting 80 miles to reserve.

Is this normal?
06 CBR1000RR, 76 CB550

Offline TwoTired

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Re: 76 550 top gear rev problem
« Reply #81 on: May 07, 2017, 04:07:17 PM »
How tall is your stand pipe?

How much fuel did you put in for a fill up?

Didn't you say you found problems with something floating inside the tank?

Lloyd... (SOHC4 #11 Original Mail List)
72 500, 74 550, 75 550K, 75 550F, 76 550F, 77 550F X2, 78 550K, 77 750F X2, 78 750F, 79CX500, 85 700SC, GL1100

Those that learn from history are doomed to repeat it by those that don't learn from history.

Offline FIREBLADE74

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Re: 76 550 top gear rev problem
« Reply #82 on: May 07, 2017, 06:33:06 PM »
How tall is your stand pipe?

How much fuel did you put in for a fill up?

Didn't you say you found problems with something floating inside the tank?

New stand pipe, it appeared to be the same as the one that was broken.

I put in about 3.76 gallons.

The problem was the stand pipe broke off from the petcock and was floating in the tank, it has been fixed.

I will say that I am pretty aggressive towards the throttle, lol. I filled up today and not even 2 miles from the gas station I get a nail in my tire, smh! I will ride more civilized once I get the tire replaced and see if I can get at least 100 miles to reserve.

What is the average to reserve? Also I run 89.
06 CBR1000RR, 76 CB550

Offline BomberMann650

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Re: 76 550 top gear rev problem
« Reply #83 on: May 07, 2017, 07:28:43 PM »
80 miles on reserve is ~2 gallons - that's nothing to scoff at!

2.5 gallon fill up for bloo.  ~100 miles on main fuel

Offline TwoTired

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Re: 76 550 top gear rev problem
« Reply #84 on: May 07, 2017, 07:59:51 PM »
80 miles using 3.76 gallons is 21 MPG.  Did you drive on and add miles after switching to reserve?

The owners manual states the tank is 4.2 US gallons including 1 gal in the reserve supply.

That's pretty sucky mileage for a cb550, imo.

For comparison my all stock 76 CB550F gets pretty near 50MPG on a road trip through the twisties.  My 77 Cb550 is quite similar, though I haven't calculated it in a while.

Do you turn off the fuel tap when stopped?  Sure you aren't leaking it out somewhere.  If not, check your spark plugs for soot.

Cheers,
Lloyd... (SOHC4 #11 Original Mail List)
72 500, 74 550, 75 550K, 75 550F, 76 550F, 77 550F X2, 78 550K, 77 750F X2, 78 750F, 79CX500, 85 700SC, GL1100

Those that learn from history are doomed to repeat it by those that don't learn from history.

Offline turboed13b

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Re: 76 550 top gear rev problem
« Reply #85 on: May 07, 2017, 08:30:28 PM »
I have plenty of bikes working on pods and run just as smooth as stock. It takes a while to learn how to tune and many people give up way too quickly.
I too believe it's possible to get a bike to run on pods, BUT, only a dyno proves that to be true. And I have yet to see anyone provide a dyno graph to prove pods run as well as, or better than stock air boxes. So, take it with a grain of salt that a bike is running "as well as". Because the very nature of the change is well documented to negatively effect the performance versus stock induction.

I have both a stock intake system and pod intake on cb550's and so do my friends and we constantly race. It is no better or worse I can hop on each bike back to back and won't notice a difference. A dyno would be a waste of time and money.

Offline TwoTired

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Re: 76 550 top gear rev problem
« Reply #86 on: May 07, 2017, 09:15:19 PM »
I have both a stock intake system and pod intake on cb550's and so do my friends and we constantly race. It is no better or worse I can hop on each bike back to back and won't notice a difference. A dyno would be a waste of time and money.

But, it would back up your brag.  Just sayin...

You know, a simple 1/4 mile timed measurement for each of your bikes is pretty easy to do.

Then just compare that to stock performance numbers.  It would give you a benchmark.
Lloyd... (SOHC4 #11 Original Mail List)
72 500, 74 550, 75 550K, 75 550F, 76 550F, 77 550F X2, 78 550K, 77 750F X2, 78 750F, 79CX500, 85 700SC, GL1100

Those that learn from history are doomed to repeat it by those that don't learn from history.

Offline calj737

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Re: 76 550 top gear rev problem
« Reply #87 on: May 08, 2017, 05:04:51 AM »
I have both a stock intake system and pod intake on cb550's and so do my friends and we constantly race. It is no better or worse I can hop on each bike back to back and won't notice a difference. A dyno would be a waste of time and money.
Respectfully, Turbo, thats anecdotal evidence at best. Who's to say both motors are equally healthy? That the rider behaves the same way each time, each bike. A dyno run is pretty inexpensive, often free on "Festival Days" and is the only way to prove it. Science, Math and all that...

But as I said, I too believe its quite possible to get them to run well, just doubt that they will run "better" all other things being stock and equal.
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"Of all tyrannies, a tyranny sincerely exercised for the good of it's victim may be the most oppressive. It may be better to live under robber barons than under omnipotent moral busybodies. The robber baron's cruelty may sometimes sleep, his cupidity may at some point be satiated, but those who torment us for our own good will torment us without end for they do so with the approval of their own conscience." - C.S. Lewis