Hi all, i am doing a service on my lovely CBR 600f 87 and i was thinking of punting some performance parts. I am thinking of getting Barnett Complete Kevlar Clutch Kit with OEM Gasket (link) and some Iridium sparks. Any thoughts on the mater?

 

The clutch kit looks good, but I'm not sure it would be a good idea to change the plugs to Iridium. A set of the factory NGK/Denso copper spark plugs will work just as well and cost much less. The only benefit would be a longer replacement interval (with the iridium), but they will not make any additional power. I would suggest a set of oe NGK plugs, part# dpr8ea-9.

If you want to pick up the power a bit first make sure all the factory recommended maintenance is up to spec. Then change the air filter to a higher flowing one (K&N, Uni, etc.), upgrade the muffler/pipe, and install a jet kit for the carbs to match the fuel with the extra air the engine is able to move. Stage 1 should be enough unless you plan to drill out the airbox & upgrade engine internals for more power. In that case a stage 2 kit would probably be best.

Another cheap way to make the bike faster is to change the front and/or rear sprocket to a shorter gear ratio. Changing the front sprocket to 1 tooth less and the rear sprocket to 2 or 3 teeth more will net you a substantial increase in acceleration with a bit less top speed in each gear. The top speed is still well over 100 mph with the -1/+2 sprocket setup and definitely worth the change in my opinion since I don't need to ride that fast anyway

 

Honestly, I'd shy away from the kevlar clutches. I've heard a few horror stories about how they are grabby and hard on friction plates. With the modest power these bikes produce, you will not notice any improvement over oem.

I agree with tahoe on the plugs. Ir is great for engine with plugs that are a pita to swap... not the case on these bikes. Today's technology doesn't necessarily help with yesterdays bike.

 

The sparks i get tho i am not sure abut the kevlar. I had no problem with my Suzuki GS500 E 89 that was even lower on power than the Hurricane. Maybe the horror stories you heard of where caused by something else?

 

do not drill the airbox!!!!!!!!!!!!!!! it lets air out from the ram air design-------------honda designed it that way- take the air plugs outta the vents into the air box-- all you need is a supertrap slipon 15 discs open end cap and a jet kit with the k and n filter thats it--keep the plugs that came in it check them and may need to run a hotter or colder plug on your altitude- i had a hurricane for 10 years and 3 other people i know had them also back then-- all types of combos but the one worked best was the one i told you---- barrnett clutch great but stock springs to have that smooth feel--good luck

 

What ram air design? The f1 does not have one. In fact of you open it up to ram air you end up with all sorts of issues. I know as I converted my f1 to ram air back in 2000, then fought it for close to three years before going back to the normal aspiration the f1 has. When it worked right(humidity, temperature, density, etc) it was amazing. But if one of those variables was off I had to play with ram lengths, pipe opening amounts, etc. Read up on converting these bikes to a streetfighter, they all go through the same stress I did, without all the performance parts. what plugs in the airbox are you talking about? I have worked every inch of the hurricane over and over and over(ad infinitum) and never saw a single plug in the airbox. There are the 4 inlets from the carbs, the two main air inlets through the frame into the low pressure area inside the fairing, and the vent tubes for the carbs bowls and low pressure section. Nothing else.

Drilling the airbox allows for the low pressure air underneath the gas tank to be tapped for inlet.

I have had my f1 since 1999. I bought it from the second owner. I put more than 30,000 miles on it, raced it in drag races, road races, done 400 mile single day blitzs, etc. I tried multiple exhausts. The yoshimura slip on was great for a slip on. The supertrapp was easy to tune with the discs, but sounded horrible(also did not assist much at all, like from 0 discs to 7 was no change in E.T.). My favorite is my current. The D&D head back tri-y exhaust.

I have worked mine over to the point it was running a 10.9 1/4 mile at 129 mph. It's not that fast anymore(more like a 11.9 or so), but the cane CAN do it with a good rider and a LOT of mechanical tuning. I did it on C16 race gas, a strapped front end, aired down rear tire, suspension tweaks, weight removal, the ram air box we fabbed for it, raised compression, PnP job on the head, carb work, regearing, webcams, etc. It's just time and money to make anything fast.

 

Nice! this kind of advice is just what i was looking for to give my 88 a boost. I got it with a old vance and hines already put on, no idea if carb was jetted for the pipe p.o didnt know either. Are modern pipes better then mine or will i get about the same performance out of a newer pipe. Also short ratio gearing mod. what is the exact size of the sprockets being put on. i want to do this mod but not sure if someone before me already has on my bike. thanks in advance for any help

 

If you are looking for better acceleration, -1/+2 f/r is a typical setup. Preserves chain length so you don't have to knock links out. Keep in mind you do lose top end.

 

I went with a -1 front sprocket & stock rear when I replaced everything, and I would still like to add one or two to the rear to make it accelerate a little quicker. You can do well over 100mph with a -1/+2 change which is more than fast enough for me