'01 Honda CBR600F4i PC35 - Part 1 - Introduction

Few months ago I was looking to buy a new project bike. There was one enduro bike for sale nearby which peaked my interest and price seemed reasonable. I contacted the seller but the deal fell apart and he decided not to sell it for some reason. I weighed my options I decided to try to sell my '91 Honda CBR600F PC25. On a whim I made an add for my PC25 and on the next day it was already sold. 

Now that I got more room available in the garage I started to look for a newer Honda CBR600F4i. PC35 seemed like a good option since I had purchased some parts earlier (more about those later) which would be easier to fit to PC35 than PC25. After browsing market places for available PC35s I ended up buying this one a week later. 

It had 50 058 km on the trip meter when I bought it so it was time to get it serviced. I took it to a local maintenance shop. Main thing was to check clearances of inlet and exhaust valves. Engine oil, oil filter, air filter, spark plugs and coolant were changed and charging, battery, fuel injection, suspension, control system, brakes, lights, tire pressures etc. were checked at the same time.

Overall this bike is in good condition and rides nicely. I haven't got to ride it too much yet but first impressions are good. It feels more nimble and responsive than my previous PC25 and has better ergonomics. There are small things I want to fix along the way such as rust on the silencer, scratches on the right side fairing and crack on the windshield but are not urgent at the moment. 

Petrol Circus Custom Bike Show @ MP 20 Motorcycle Expo - 1st of February 2020 - Helsinki, Finland

Check out photos from this year's Petrol Circus Custom Bike Show which was held parallel with MP20 motorcycle show at Expo and Convention Center of Helsinki. Show gathered together around 100 custom motorcycles to compete in four classes: Custom, Street, Classic and Open. 

My personal favourites were Kawasaki powered Sulo Chopper, Kalevala themed Harley-Davidson PanShovel Indian Larry Tribute, brat style/tracker Honda CB400N, 1980 Suzuki GSX750 cafe racer, Suzuki GSX-R 1340 street fighter, 2-stroke Suzuki RGV250 and 184cc Honda Monkey Turbo 😎

Royal Chopper 'Prince of India' @woodlegchoppers

'91 Honda CBR600F PC25 - Part 4 - Custom brackets for round headlight

I've had a 8 inch round headlight lying around which I bought originally for my '87 Yamaha RD350LC F2 project but never got time to install it before selling the bike. I had headlight also for sale for a while after that but no one was interested to buy it so it just stayed untouched in my shelf waiting for another suitable project.

8 inch round headlight

Regarding this build I haven't decided any specific style go with but I wanted test how a round headlight would look in front of my CBR600F. It was also good time to do that while I have front fairings removed. I've made earlier similar type of brackets for '72 Suzuki T250J and used them as a reference for these ones too. I made subtle changes and updated dimensions to suite better '99 Honda CBR900RR SC33 front forks I swapped last time. I still need to design and fabricate a stopper for the headlight to keep it from tilting while driving. I'm not 100 percent sure how to make it yet so it will have to wait for the future. There's also things like what kind of gauges I will use to think about.

Assembly drawing

Layout drawing with main dimensions

After making part drawings for collars and plates it didn't take much effort to start fabricating them out of sheets of stainless steel. It's not the easiest material to work with since it tends to wear out drill bits and warp easily with heat. I didn't end up using many power tools other than electric drill and Dremel this occasion so it took a bit longer to finish them. Quickest way of course would have been to get them cut with laser or water jet cutter.

Part drawing for collars

I cut out blanks for collars with a plate shear
and then marked holes and rounds to corners

I started by drilling holes...

... and then rounded all corners with a file and sanding block

I used an affordable sheet metal bending machine
to bend edges of collars and rest by hand against forks

I finished outer surfaces of collars with a scotch brite wheel

Part drawing for plates

Sketched outlines of plates with pencil
and used washers as templates for round corners...

I started by drilling holes,..

...then cut both plates out with a hand saw
and finished edges with file and sander

I used a vise brake for bending...

...and checked angle of bends with digital angle finder

Last step was to clean plates with scotch brite wheel

Parts for headlight brackets

Headlight installed

'91 Honda CBR600F PC25 - Part 3 - '99 Honda CBR900RR SC33 front fork swap

I thought about couple of options I could upgrade my stock '91 CBR600F PC25 front forks to. I ended buying a set of front forks and wheels out of '99 Honda CBR900RR SC33 Fireblade. I thought USD front forks would have been too expensive and more difficult to install. I really like nineties six spoke Honda wheels which both share and I wanted to keep them on this bike. I had a hunch that these forks could just bolt on directly without any modifications but I wasn't totally sure of it. It was time to find out once I got them.

'99 Honda CBR900RR SC33 front forks

'99 Honda CBR900RR SC33 wheels

I started by taking off front fairings of my CBR. I used same technique than previously to hoist front end of my bike up. Now that fairings weren't in my way I decided to switch location of hoist strap little bit further back so that it wouldn't interfere removal of top yoke. Old front forks came off after taking off clip ons and top yoke.

Front fairings removed

Hoist strap location

Stock CBR600F front forks removed

Installation of SC33 Fireblade forks ended up being were easy since both front forks share same steering bearings and stem dimensions. Turning radius stays same as before and nothing makes any unnecessary contact. Only thing that requires modification is steering lock mount on frame. I didn't mess with it yet since I'm not totally sure what I will end  up doing with it. At the moment front forks are just installed for mock up. Let's see what comes up next 😎

I installed stock control switches and clutch perch for now

Ignition switch cannot be installed without
modifying frame mounts

Differences between PC25 and SC33 ignition switches

'91 Honda CBR600F PC25 - Part 2 - Service for front shock absorbers

Here's a short story about how I rebuild my CBR600F front shock absorbers. Other side of them was leaking quite a lot so I decided to rebuild them with Pyramid Parts Front Suspension Overhaul Kit made for Honda CBR600 F2 F3 1991-1998 (IB11 & OB22). You can find part diagrams for '91 CBR600F for example from CMS. Here's part diagram for front fork which helped me for this small project. First step of it was to lift up the front end of the bike and to get the front shocks out.

Hoisting up front end of my bike
with Chain Block & Tackle

I tide a cargo/load strap around front end frame beams and secured it with a knot which I then attached to the chain block and tackle. Piece of wooden block helped keeping the strap away from cables running aside frame beams.

Closer look of cargo strap tide around
upper frame beams

Front brake calipers had be removed
to get front wheel out

Front fender is secured with two bolts on each side of the fork
and other one also holds brake line hose

Both of those bolts can be loosened with front wheel still in place.

After getting the front wheel off I was able to remove forks out of yokes. I started by removing securing circlips (5) from top of each fork and removing clip-ons. Each fork is secured to top and bottom yoke with two bolts (21) and (11). After getting them out forks just slide out.

Front forks are off!

First step of rebuilding them was to drain out
the old fork oil. Oil drain screw is
located below brake caliper mounts.

I used a small screw driver to remove
old dust seals...

...and circlips which secure oil seal below it.

Then I secured front shock absorber to a vise...

...and used an impact driver to get the lower tube bolt out.

After removing circlip and lower bolt tube can be separated
from stanchion just by pulling them apart.

Condition of old slide and guide bushes.

I disassembled the rest of the forks after removing the lower tube and cleaned them with brake cleaner. Springs inside the stanchion are loaded so be careful when you take out the top cap. I applied bit of pressure to them while unscrewing to stop them from flying off. They are made out of aluminum so those fine threads which keep them in place can be easily damaged if you're not careful with them. I decided to reuse old O-rings in them together with copper washers in lower tube bolts.

I used brake cleaner to clean parts of shocks.

Pyramid Parts Front Suspension Overhaul Kit for
Honda CBR600 F2 F3 1991-1998 (IB11 & OB22)

Fork oil seals

Slider and guide bushes

Stanchions rebuild with new parts.

CRC Soft Lock threadlocker...

...for securing lower tube bolts.

Since I don't own any special tools for rebuilding forks I made a washer looking thing out of nylon sheet which I placed on top of oil seal when I hammered them in with a small punch. It kept them undamaged while hammering.

Nylon washer to keep oil seal undamaged
while hammering it in with a small punch.

Circlip back on to secure oil seal.

I used a rubber mallet to gently
hammer in dust seals.

Rebuild shocks ready to be put back to the bike.

Remember to add threadlocker also to brake
caliper bolts. They can easily get loose without it.

I bought 2 litres of Belray 10W fork oil...

...and measured roughly 0,508 litres for each shock 
which was recommended by service manual.

Small funnel helped with refilling shocks with fork oil

Ready for a test drive 😎