Hey guys,

I just wanted to do a full tune up, getting ready for spring rides, long trips, and group rides, etc.

* Last week flushed the brake fluid & coolant. Replaced with Motul brake fluid, cleaned calipers, pistons; and replaced to a factory pre-mixed Honda coolant.

* Both sprockets and chain were replaced (520 conversion) recently.

* New clutch cable is going in next week. And a new clutch lever.

* Next I want to replace the spark plugs and air filter. I'm confused about the plugs - some say, I need NGK IMR9C-9H, some say IMR9A-9H. (Both are laser Iridium NGK plugs). What's the difference in the "C" and "A" designations? Even the Honda OEM parts dealer doesn't know.
My next question is which Air filter to go with: K&N or OEM {Pros & Cons of both?}

* And lastly, any other recommendations for the tune up?

Thanks in advance!

 

for the plugs i know the F sport(2001 f4i with split seat) is suppose to go with A(what i got on mine); later years one uses C, its something they changed over the years with the ecu suppose to make it more a sports tourer bike(heard from somewhere, not too sure if its true)

k&n and oem are both paper filter, K&N have higher flow rate so will be better to go with power commander; oem is the one to go for without power commander

edit: the A and C difference in plugs are the tips are different shape

 

Were you over at Jackie's the other day? I had the other f4i there

You can use either spark plug, the only difference is that the 9C has a tapered cut electrode. Read more here: https://cbrforum.com/forum/f4i-main-...will-ok-85786/

I've heard that with the K&N you will lose a little torque down low and gain some up top. I don't think you'll notice much of a difference either way. I choose to run OEM paper ones because they filter more dirt. If you want a K&N, I have a spare one I'll sell you for $20. Its in great shape, just needs to be washed and re-oiled.

How many miles are on the bike? You might be due for a valve adjustment. I recently did mine and it made a huge difference in throttle response and it opened up more power too.

 

Yes, that's me! I was at Jackie's place and you were the only other guy with an F4i. So, I've done some research and I'm going with the OEM paper Air filter. At least that's settled.

As for the Spark Plugs, I'm still confused about their differences, and which would be a better one, and why?

Oh, and I'll get my valve job done in 2015 or another 10K miles. It's running well for now. Thanks!

 

Just get the ones that are suggested for your year. There isn't one that's better than the other.