I use it simply for the 17 mm hex and safeteywire hole.

 

That feature does come in handy when tightening to recommended torque.
The same filter pn KN-204 also is used on my FZ1 and my daughter's FZ6.
So it comes in handy when buying some to keep in stock.

Interestingly, the RC51 manual recommends 19 ft/lbs torque, while the FZ1 and FZ6 manuals recommend 12 ft/lbs.

The Honda 19 ft/lbs value is pretty damn snug, so I've taken to using the 12 ft/lbs value with no problem.

 

^ because the RC51 runs higher oil pressure??

 

K&N is an over glorified HiFlo filter...charge an extra $5 to have a nut welded on

This is what I use. It has better media in it than the K&N and more of it too.

 

Got this back from K&N...

Hello,

Thank you for your interest in K&N products. The By-pass valve engages at 14.5 PSI. If you have any further questions please reply to this email or contact customer service at 1-800-858-3333.

Thanks for writing,

Emily Swanson
Product Specialist – ext. 4082
K&N Engineering Inc.
(800)858-3333

Jondog, here is an explanation of bypass rating and why it matters...

Oil filters, and their selection, can be a mystery to us since we are not able to see how or how well they are working without getting very dirty, hooking up a bunch of instruments, and doing extensive testing on both the filter and the oil. Understanding how the oil filter works with the oil pump to provide the engine with an adequate oil pressure of relatively clean oil at all times is the first step in knowing what filter to use. Most importantly, it is more important to have the correct oil pressure and flow through the engine at all times than having the cleanest oil possible. Motorcycles use what is called a full-flow oil system. Assuming that the oil pump is properly spec'd to exceed the needs of the engine at any given rpm, the oil filter must clean the oil without interfering too much with the oil pressure and flow. Since the filter works by forcing the oil through a filtering medium, some measure must be taken to ensure that the pressure loss in the filter does not exceed what margin the oil pump has over the pressure and flow requirements of the engine. This is where the bypass valve in the oil filter comes in. If the pressure between the engine and the filter ever drops below the pressure between the pump and the filter by an amount over the PSI setting of the bypass valve, then the valve opens, allowing oil to bypass the filtering system, and balancing the oil pressures. Since motorcycles tend to be very high performance machines that get driven very aggressively, have very little flywheel effect, have the smallest oil pumps allowable, and rely only on oil pressure for motor bearings, the bypass valve PSI setting tends to be quite low, 8-11psi in most cases, compared to 11-17psi for more robust auto systems. The bypass valve also ensures that engine oil continues to flow, even when the filter has clogged, and during startup when the oil is very viscous compared to how thin it is at running temperature, and that the pressure differential does not destroy the element. Ensuring that the oil filter that you choose not only fits, but has the correct bypass valve setting is very, very important. The best explaination of the oil filter that I have read is by George Nehls. Also, seeRoss Presta's Oil Filter Experiment , another is The Oil Filter Study.

LBP - 2-7 PSI, Low Pressure By-Pass Valve
BP - 8-10 PSI
MBP - 11-17 PSI, High Pressure By-Pass Valve
HBP - 18-25 PSI, High Pressure By-Pass Valve
SHBP - 30-45 PSI, Super High Pressure By-Pass Valve
XHBP - 50+ PSI, Extra High Pressure By-Pass Valve AD - Anti-drainback valve

The best cross reference resources online are WIX and Baldwin & FRAM. With regard to filtration, suppose 100 particals of 20 microns were passed through an oil filter and 95 of those were captured in the element. That filter would be rated at 95% efficent @ 20 microns. This is how single pass (SAE J1985) filter ratings work. True industrial filters will be rated at 5, 7, 10, 12, and 20 microns. A filter must be rated for each particulate size under single pass conditions. Remember that the oil in your engine will cycle through the filter countless times during the filters life. Some types of filters may perform better under multi-pass conditions than the single pass numbers would lead you to belive. Some other ways of rating oil filters for multi-pass filtering have been proposed, but none have been standardized that I know of. Three different spin on filters exist for late model Honda sportbikes. They are made by Toyo Roki Mfg. Co., LTD. in Japan. The three filter generally correspond to bikes made in different decades:

 

i use wix on all my shit. would be nice to have the nut though. last two times i had to change the filter on my bandit (behind the header) i had to drive a screwdriver through it.

only put it on hand tight though

 

I used their filters on my superhawk with no ill effects. Will put on the RC next oil change.

 

holy shit what a thread bump.


just for the record. k&n filters have been banned by many racing organizations for their tendency to fail and oil down the track.

 

That's from the tendency to over tighten them by the nut , they should be tightened to K&N's recommendation , no other , they made the filter

 

i don't believe that for a second.

k&n had a recall on some of their filters, and there is a VERY long list of failures from them.

 

You can believe whatever you want , I've been using their oil filters for 20 years without a single problem. The failures were at the nut , the filters come with tightening instructions printed right on them stating how far to turn after gasket contact , they even have index marks on them. A wrench is not needed to tighten an oil filter , on cars either , but people think they know better , think they know what they're doing , then they cry about it to anyone that will listen. Most of the time they should be shouting ''look at how stupid I am''. I checked the numbers of the filters I had back then , one was even on one of my bikes , I threw them away after oil changes like normal , no leaks.

 

your anecdotes aren't evidence of anything unfortunately.



the failure rate on the k&n filters is high enough that it's become a safety concern, and many organizations have banned them. if you have one on your bike, it won't pass tech, period.



what's more interesting is that the posts about the failures are NOT from the people who had the failure, so your presumption that "they cry about it to anyone who will listen" isn't really accurate here.




you can use whatever you want, i'm not telling you not to. but i do not think it's sage advice to suggest someone use a filter that has a bad track record for failures and has been banned from competitive use across many different sanctioning bodies.

 

Cause and effect , morons with a wrench and oil filters with nuts. It was easier to ban them all than to check production runs of filters. I live in the southeast US and most of us ride year round , I literally know hundreds of people with bikes , I've never heard of an oil filter failure first OR second hand.