Flooding Fireblades: Sorting the fuel system on a '97 CBR900RR

Butterfly is under-gasoline...

Weather's closing in on us up here in Canada.  I had the 'Blade up on the bike lift last week thinking the riding season was over as we got buried in our first snow storm.  The next week suddenly warmed up due to a tropical storm somewhere, so I primed the Honda and got it going again (I'd run it dry in preparation for winter hibernation).  Unfortunately, it flooded itself and ended up with the first two carbs full of fuel.  You can see the wet in carb bell on the left.

I think from now on I'm going to turn off the fuel tap from now on whenever it's sitting rather than trust this touchy carb set to do the right thing.  Instead of taking the Fireblade out for a weirdly warm ride on Sunday, I was sitting on the driveway removing the carbs and changing the oil.

On the upside, pulling the carbs gave me a chance to replace all the rubbers (airbox and engine side), which needed doing (I'd been holding them together with some cunning chemistry).

New rubber bits on old bikes make a huge difference.  Even the engine side ones (which still looked good after 23 years of service) were hard and unyielding compared to the new ones.  I'm curious to see how the new ones seal in comparison.  I got the airbox rubbers from KW Honda in Waterloo, who were very responsive on email which hasn't always been my experience with local dealers.  They got four rubber airbox boots for a 23 year old bike that's been out of production for decades in less than a week, during a pandemic.  It's good to know my local Honda dealer supports older models.

I picked up a second carb set from NCK Cycle Salvage in Woodstock last fall for less than the price of the broken bits I needed to replace on the one that came on the bike.  I now have an entire second set of carb hard parts I can go to if I need any other bits.  The set they gave me (other than needing a choke pin on one of the carbs) was complete and balanced, and when I threw it on it worked a treat, so I ran it all summer having never gone through it.

With the carbs off in the late autumn sun last Sunday, I finally took the float bowls off and discovered that they were pretty grotty (when I emptied them the fuel came out brown).  It didn't take long to clean everything up, and I got carb cleaner deep into the jets and upper parts of the carburetors too.  It all went back together nicely and I was also able to lubricate and clean up the throttle action with the unit out, though it already moved sweetly.

With the new rubbers on, I put the carbs back on after work this week and they came back together nicely.  It's a good idea to attach the two throttle cables to the carb set while it's still loose.  Once the carb set is on the bike getting the cables on is a real bugger.

I went over all the fasteners as I went making sure everything was snug and leak free.  I've still got to put new oil in it, but we have a above zero day this Saturday so I'm hoping I can take the 'Blade out for an end of year run to make sure everything is five by five before I hibernate it for the winter.  Months hence after the winter of second-wave COVID pandemic, the Honda will be ready to go with fresh oil and a clean and capable set of carburetors.

This forgotten Honda is a real treat to ride this summer and is a very different thing from the Tiger.  One is a long distance tool built for pretty much anything, the other is more like an aeroplane designed for the road.  The 'Blade weighs over 20% less than the Tiger and makes almost 40% more power.  On interesting paved roads the Fireblade is in a class by itself.  Unfortunately, I live in a place deficient in interesting roads and track days in Ontario, even when there isn't a pandemic, are needlessly complicated (you basically have to show up with a race bike or rent something, there are no ride-on days for road bikes here).

The other nice thing about the Honda is how it's built for a single intention.  That focus on light-weight means getting in to work on it has been accessible and enjoyable.  Honda's aren't just designed ot run well, they're designed to be worked on too.  As my first Honda this bike has been a positive introduction to their engineering and design philosophy.

If I lived somewhere with interesting roads and reasonable track days I'd be hanging on to the Honda indefinitely as it was designed to express the dynamics of riding, but living in South Western Ontario, devoid as it is of interest, means I'm going to try and move the Honda on in the spring... assuming anyone is left post second-wave to buy it then.  I'm going to miss what it can do though.  Having this bike has opened my eyes to what a motorcycle is capable of dynamically.

FOLLOWUP

We've got a major winter storm (100km/hr+ winds, rain and snow mixed) rolling in, but I got out yesterday afternoon for an hour and the 'Blade is even sharper than it was before.  The new rubber seals tighter, making the engine even more responsive, and the cleaned carbs are razor sharp in responding to throttle.  When I got home (cold, it was only a degree or two above freezing), I closed the petcock and ran it dry before parking up the 'Blade and wrapping it up for the winter.

After our long cold winter with second wave COVID19 piled on top, it'll be ready to go in the spring...

One Tight, Not Too Tight

Now that the CBR900RR Fireblade project is sorted and on the road, I'm finding myself doing what the original intent was in getting it:  learning from a different type of motorcycle.  Unlike the heavy industry Kawasaki Concours, or the SUV of motorcycling Triumph Tiger, the 'Blade was built to a different design brief. The other bikes were over engineered heavy to last, but the the Honda is a feather.

That philosophy is at odds with the heavy handed git who owned it before me and managed to maintain it into such a state of disrepair that it kept it off the road for years.

From the rear brake cylinder that was assembled backwards and over tightened, to the over tight wheels and the slipping clutch I've just adjusted to actually be at spec rather than over-tightened, I'm finding the Honda was a victim of a heavy hand and unsympathetic mechanical inclination.

When I was a teen my dad was talking me through a head gasket repair on one of my first cars.  We weren't minted, so the only way I was driving was if I could keep an old car on the road; mechanical training was an implicit part of vehicle ownership for me growing up.  As we were tightening the head back on he made a point of talking me through the bolt pattern - always tightening opposite bolts so it would seat evenly, and then said something that I've never forgotten as we started tightening down the head:  "always one tight, not too tight."  I guess the guy who abused this lovely piece of Honda engineering into years in a garage never got such good advice.

Mechanical sympathy is an important part of maintaining any machine, but especially a motorcycle, where if you are cack-handed you can end up seriously hurting yourself when it breaks.  In that way, motorcycle mechanics are a lot like aircraft mechanics, it's a do it right or it can go very wrong kind of situation.

Part of that sympathy is taking the time to understand what the engineers who designed the machine want you to do in terms of looking after it.  In the case of the CBR900RR, Honda would like you to leave 10-20mm of play at the end of the clutch lever - this one was set so you could strum it like a guitar string.  This play is to ensure that the clutch fully disengages when you let go of it.  An over tightened clutch cable means it's always set to be slightly pulling and engaging the clutch.  Making it too tight isn't just a failure of the hands, it's a failure in thinking that wounds the machine.  In this case, the over-tightened clutch cable explains why the 'Blade was slipping RPMs when I opened it up.  A sympathetically tuned motorbike will give you a purity of interaction that allows you to more fully understand the machine.  This is one of the reasons why I value technical fluency so much, it puts your ability to operate technology into focus in a way that the technically ignorant will never realize.

***

Meanwhile, in the land of Tim where he's trying to keep a 17 year old European and a 23 year old Japanese bike rolling during the perilously short Canadian riding season, the Tiger's stalling when hot continues.  I've ordered a replacement air idle control valve from Inglis Cycles, who have once again exceeded expectations during a pandemic by sourcing the part from Triumph in the UK and getting it to me in about a week.

One of the nice things about the Tiger is that it's fuel injected, so all that carburetor management is taken care of, but the evil end of computerized fuel injection is that after seventy six thousand kilometres it's finally gone wrong, and an electronic system like that can go wrong in a lot of different ways. 

I'd never gotten into the Tuneboy Software that came with the Tiger (the original owner installed it along with a Power Commander), because if it ain't broke, don't fix it.  But now that it's broke, I got going on it the other evening.  Getting into the bike via a computer was pretty cool.  The software is Y2K retro-hip and the connection was straightforward.  The 20+ pages of instructions weren't really needed (I'm handy with computers).  Windows 10 automatically recognizes what you're plugging in (back in the day, WinXP would have needed drivers installed), and the software is responsive and quick to connect.  It occasionally drops connection, but unplugging it and plugging it in again resolved that each time.


The compact disk (told ya, Y2K hip!) had all of the stock maps for my year of Triumph Tiger 955i engine on it, so I saved what was on there in case it was some kind of cool specialty map the previous owner had worked out (dude worked at a nuclear power plant, so don't underestimate his tech skillz), and then I flashed it with the stock numbers, which took about 20 seconds and returned a confirmed result.  There is a slight lag, but otherwise this is easy to use stuff.

I then played with the diagnostics tool for a bit, hoping for some data that will help me isolate the hot idle stalling fault.  The software says there are no errors (promising that this is that mechanical failure then), and the only thing that looks out of place is a strange return on the engine temperature.  It seems to read accurately and then show -40, even when the fan is coming on, but if the fan is coming on and the temperature gauge on the dash is reading normally, I suspect this is something to do with how the software syncs with the on board computer rather than an actual fault, but I'm going to keep it in mind.

The problem with an idle fault on a fuel injected bike is that the engine management system is taking in data from a number of sensors and using it to balance engine activity, like idling, based on that information.  I've got the mechanical component that regulates idle on the bike incoming, and I hope that resolves the issue, but what I fear is that it's something else, and with these complex electronics systems could mean that anything from a dozen different sensors or relays to a loose or broken wire.  With any luck, it's that idle air control valve and I'm back on the Tiger... and the Honda, just not at the same time.

Athletic Intent

Coming to terms with the Fireblade...

The first couple of times I rode the Honda I found the riding position hanging over the gas tank somewhat extreme.  The bike was astonishingly light compared to others I've ridden (dirt bikes excepted), and changes directions like it's telepathic, though the clip on handlebars mean you don't get a lot of leverage when turning.

While the riding position is pretty extreme compared to the adventure and sports touring bikes I've ridden recently, it's the bike's geometry that really surprises.  The rake on the front wheel is nearly vertical, and feels like it's right under your hands rather than stretched out in front of you.  This results in those telepathic direction changes.

I've actually jumped on the Fireblade and had my groin seize and had to stop to stretch.  I've taken to doing some limbering up, Zombieland style, before I get moving on the Honda.  It's nothing that a bit of yoga doesn't address in my 50 year old self, but the 'Blade is an extreme thing that demands physical interaction; it reminds you that it's a SPORTS bike.

So, why be uncomfortable?  It might be argued that the CBR900RR is an appearance bike; something you put on to get attention, but that isn't why it's the way it is.  The 'Blade is built to explore the physical limits of what a motorcycle can do - it's the opposite of a cruiser, it's about the sport of motorcycling, not the appearance.  Every choice on the bike, including the riding position, is designed to maximize speed and agility.  The 'Blade is more of a boxing boot than a high heel.

1997 Honda Fireblade CBR900RR

by timking17

on Sketchfab

One of the most shocking things about riding the Fireblade is its acceleration.  I've yet to own a bike where I can't turn the throttle to the stop opening it up... until the 'Blade.  It's so light it pulls strong through the first sixty-five hundred RPMs, but then it lunges to the redline in a startling manner.  Even in higher gears I haven't turned the throttle to the stop yet.

The CBR900RR is described as a bike that is engineered to exceed your abilities but is accessible enough to show you how to improve them, and that's just how it feels.  As someone who has gone out of his way to explore motorcycling, it checks a box for yet another aspect of the sport to discover.  I won't be putting big miles on the CBR, but they'll be highly intentional and informative ones.

COVID19 Rapid Restoration: Fireblade for the first time since Obama was President

The Fireblade project has come together nicely thanks to the strangeness we all find ourselves in with the COVID19 pandemic.  With a suddenly extended March Break, I was able to sort out the fairings, get the LED indicators wired up and finalize all the plumbing for fuel delivery.  It was all fiddly, last minute stuff, but with the time in hand it was easy to sort.  The adjustable indicator relay got wet when I cleaned up the bike which prevented the LEDs from flashing, so it got waterproofed and sealed.  The first ride was enlightening...

360° Video from RICOH THETA. - Spherical Image - RICOH THETA

That's the first time it's been running since Obama was in office.  It's a very different thing from other bikes I've owned.  I'm a big guy and 50 years old, but the yoga helps with the flexibility needed to ride this machine.  The foot pegs are significantly higher than anything I've owned before, and I'm leaning forward over the gas tank in a much more prone position than on the Tiger.  I was very conscious of the clip-on handlebars and the lack of leverage you have when cornering - steering on an adventure bike is much easier because you've got big, wide bars that offer a lot of pull.  The Fireblade was so much harder to turn (the weight of leaning forward doesn't help) that I actually thought the steering was obstructed, but it wasn't, it's just a lack of leverage.

After the first ride I thought, 'this thing is virtually unrideable!'  But as I was working out the details and getting used to it the riding position started to make a different kind of sense; I think this bike can teach me things.  The centre of gravity is so low, and the bike is so much lighter (over 40 kilos!) than my Triumph Tiger, while producing thirty more horsepower, that it's a significantly different riding experience.  I wouldn't want to go touring with it, but for an athletic afternoon out on nearby twisty roads, it's the instrument of choice.

The inline four cylinder 918cc engine makes a glorious noise when you crack the throttle, and the 'Blade is responsive in a way that makes any other bike I've ridden feel heavy - that's something I could get used to.  On subsequent rides I got my legs into the cutouts on the tank and once locked in place the whole thing suddenly clicked.  It'll take all the core work I've got to work with it, but this machine expects you to take riding as a sport rather than a leisure activity.

So far I'm at $1200 for the bike delivered, $250 in taxes and registration, $280 for a replacement carburetor which I cannibalized with the one I had to create a working one (if anyone needs late 90s CBR900 carb parts, get in touch), and another $200 in parts that included the shop manual, oil and filters and the LED lights.  All in I think I'm at about $2000 on the road and running like it's new again.  Looking up CBR900RRs online, a one a year older model with three times the kilometres is on for $2800.  Low mileage mint ones are going for $6-7000.  I think I could sell it in a year for a thousand more than I put into it.

When the pandemic happened here just before March Break I took home the Structure Sensor 3d scanner and did some scans, which is what you're looking at here...

1997 Honda Fireblade CBR900RR

by timking17

on Sketchfab

It's very satisfying to bring the 'Blade back to life.  Now that the mechanicals are in order I'm thinking about racing stripes.  Amazon has some well reviewed ones on for a good price, I'll give them a go rather than painting them on.

Unfortunately I'm stuck for getting the bike safetied and registered on the road because everything is closed at the moment.  I'll spend the time making sure everything is order and looking to the aesthetic details and hopefully I'll be able to put the bike on the road when we put society back in motion again in May.

'97 CBR900RR LED Indicators and Rubber Parts

The Fireblade project has the main bits (fuel leak leading to an engine drowned in gasoline) fixed with a carb rebuild and a new petcock.  But there are lots of bits and pieces to sort out before I go get it safetied and put on the road.

The weather warms up tomorrow so I'm hoping for a ride, but Saturday was a -20° March 7th kinda day, so into the garage I went to get the little details worked out.

I was initially going to hold off on the LED indicators, but dead bulbs and broken covers on a 23 year old motorcycle meant the LEDs were actually the cheaper, easier and more modern looking fix anyway.  I'd brought a second set when I got the ones for the Tiger, and also got an adjustable indicator relay, so I had all the parts on hand.

The rear indicators look like they were attached by a monkey.  I ended up pulling them all off and removing all the stripped, half installed wood screws that were holding them in.  I then drilled a hole in the rear plastic under-tray and mounted the second set of LEDs I had on hand from the Tiger upgrade.

The wiring was pretty straight forward with green being ground on both indicators (connected to black on the LED) an orange to LED power (yellow) on one side and light blue to LED power (yellow) on the other.  The LEDs also have brake light function where they strobe when you first press the brake.  Both red cables on the LEDs go together into the middle pin on the brake lights.  It works a trick:

Front LED indicators working:  https://photos.app.goo.gl/4psz7VfHg6mLnvcK6

Rear indicators working with brakes:  https://photos.app.goo.gl/AKJeo69DCpV4gzGAA

***

Some other odds and ends are also proving troublesome.  Living in rural Canada means everyone's still in love with imperial sized fasteners.  All our local hardware stores have rows of 'em, and maybe 2 metric bolts.  It was tricky figuring out the sizes of missing fasteners anyway, but some internet research into OEM parts supplier parts listings got me this far:


https://www.megazip.net/zapchasti-dlya-motocyklov/honda/cbr900rr-14743/cbr900rr-cbr954rr-fire-blade-28645/cbr900rrv-713455

Bolts to hold down the fuel tank:
96300-0604007
Bolt, flange (6x40)

Other metric sized bolts in the same assembly:
BOLT, FLANGE (6X20)

https://www.cmsnl.com/honda-cbr900rr-fireblade-1997-v-canada_model2523/bolt-flange-6x32_960010603200/#.Xlvt-KhKiHs

BOLT, FLANGE, 6X32 CBR900RR FIREBLADE 1997 (V) CANADA

A 6x40 metric bold means (as I understand it) a 6mm wide bolt that is 40mm long.  But metric sizing also looks like M6x40. I'm assuming their the same but don't understand why there isn't a consistent format for metric bolt sizing.

Some other resources around motorcycle fasteners:

https://www.cmsnl.com/honda-cbr900rr-fireblade-1997-v-canada_model2523/partslist/#.XlvtcahKiHs

https://www.webbikeworld.com/motorcycle-nuts-bolts-fasteners/
Lots of links to other websites.

https://www.boltdepot.com/fastener-information/Type-Chart.aspx

The bolts into the frame that hold down the fuel tank and the brace for the windshield are 6x40, but I couldn't get an M6 bolt in there.  I ended up cleaning out the thread by tapping it out again and then it went in nicely.

***

Rubber parts are particularly hard to find on this kind of bike - it's just old enough for existing stock to be gone and just young enough not to have a classic aftermarket parts ecosystem.

The cracked airbox rubber connector to the carbs is nearly impossible to find.  The only

online place I can find them is for a full set of four plus shipping from Europe and ends up at over 70 Euro ($110CAD)... and I only need one of the damned things!

I'm looking into some cunning fabrication options.  Some people have tried plumbing PBC couplings as a kind of secure bandage over the original rubber tube.  Though if I can find one that is the right diameter and well put together I might simply be able to trim it and substitute it.

Others have tried various fixes like heat shrink or inner tubes.  I'll do some more research and figure out next steps...

These guys suggest silicon hose as a temporary measure.  Since what I need is on the airbox side (I was easily able to get carb side rubber replacements), it shouldn't see too much gasoline so the silicon fix might be the quickest way forward.

These guys suggest a sealant.  Again, because it's not on the carb side this might do the trick.  In terms of cost this is the cheapest fix, so I'll probably start here and see how it goes.

I'm wondering if I can't 3d print the correct part.  There are flexible materials we can use to print objects using a 3d printer.  I suspect we're only a few years away from having a 3d printer in our garages that can print these rare parts out of flexible filaments:

Fireblade Petcock

I think I've finally gotten the fuel system on the scuppered Fireblade sorted.  The last problem (and probably what caused all the other carb and engine issues) was a leaking petcock.  I tried to take apart the existing one, but I should have listened to the Chilton manual and just replaced it in the first place.  The new one (40 bucks on Amazon) seems a quality thing.

The petcock in the tank was pretty mucky, and was leaking even when turned off.  If it was pouring gas into the carbs all the time, even when parked for long periods, it must have filled up the carb bowls and spilled over into the intake manifold and eventually found its way into the engine oil, which would explain the seven litres of what looked like muddy water that came out of the oil drain plug.

The new petcock looks like a more finished thing than what was on it.  Based on the questionable mechanics on the rest of the bike, I'm guessing this was just something that fit rather than the right spec part.  The one on the top is the new one and the bottom one was what was on the bike.  It seems odd that Honda wouldn't actually tell you what the petcock is doing by writing the position on the thing.  

The old one also was also lacking the fuel filter, and the new one with the filter on it wouldn't fit throught a tube stuck up in the tank hole.  I removed the old o-ring and managed to free up the tube with some WD40 and slide it out.  Like everything else I've found in the fuel system, it was a pretty mucky thing.  With those weird bits now out and the tank cleaned, that's the whole fuel system sorted, so hopefully it'll run like it should when I finally get the tank back on.

The goal now is to wait for a break in the weather (we've been in the double digital negative temperatures with a fair bit of snow), and see if I can put the tank back on and fire it all up.  It's supposed to be 6°C and raining on Monday, so that'll clear it up and maybe give me a chance to test the tank/petcock on the bike.

As it is, the new petcock is leak free on the tank (I just held it up and tipped it over a basin, but no fuel leaked), so that's a result!  The problems with this non-runner when I got it had me focusing on the fuel system to the exclusion of all else.  I'm hoping that after a carb rebuild and the various other fuel system nick nacks I've sorted, that's all that's needed, but you never know.

With any luck I'll actually get to ride the thing up and down the driveway later this week and find out what else it might need.  If it's sorted, I can focus on winter maintenance on the Tiger and do the LED turn signals I've got for both bikes next.  Come spring time I'll ride it over to my local motorbike shop, Mostly Ironheads, and have them do a safety on it and then get it sorted for the road.

'98 Fireblade Winter Project: Wiring & Petcocks

With the carbs sorted I'm chasing down anything else that could have caused the fuel leak into the engine on the Fireblade.  Yesterday I had the petcock out of the gas tank again and tested it over a catch basin.  Fuel flows fine when it's on, but it continues to drip when it's supposed to be closed, so a new petcock is in order.  Fortunately they seem to be a regularly replaced maintenance item because you can buy them on Amazon for not much money.

The neutral light wasn't working, so I got some LED replacements - they're super bright.  The wiring to the neutral sensor was stripped down by the drive sprocket, so I cleaned it up, reattached it and taped it up.  Voila, working neutral light again.

There were also a set of wires coming out of the drive sprocket housing that look like they go to a speed sensor which were resting on the exhaust pipe and had melted.  These too got sorted and re-wrapped.  I'm also going to fasten that loom so that it can't touch the exhaust again.

There are still lots of little details to sort, but the Honda is coming together nicely.  I'll aim to have it safetied in the spring and then run it for a few months and see if having a second bike in the garage is worth hanging on to, or it might just be sold on to fund the next project.  In the meantime, I'm looking forward to running my first true sport bike.

CBR900RR Bits & Pieces

1997 Honda CBR900RR parts, but I'm buying too many online when I'd rather buy them locally.  For someone who would rather support local business, I'm frustrated at the lack of competent parts people.  Canadian Tire needs to do better.

Fram oil filters:

The oil filter for the CBR is a fairly common filter - but the big Canadian Tire in Guelph didn't have one... or anything else I needed.  It's things like this that force me online to purchase when I'd rather just purchase locally.

Strangely, the Walmart across the street, the only place I can find the Mobil 1 oil Triumph calls on for the Tiger, had an oil filter for the Honda.  Not a great weekend for Canadian Tire.  You can't really brag on having 200,000 parts if your sales rep can't find any of them.


Winter flushing oil:
This is what I'm going to put in the Honda over the winter as it gets sorted.  In the spring I'll do a flush and go with Mobil 1 synthetic.

The only place I can find the Mobil 1 is at Walmart - it's the only time I usually go there.  Since I'm already there for the Tiger, I'll go for 7 litres and do the Tiger and CBR with the same super-oil.  Running the Mobil 1 in the Tiger has stopped any oil burning in it.  It's good stuff.

K&N Filters for CBR900:
https://www.knfilters.ca/honda/cbr900rr/900/1997
The HA-9092-A air filter is a strange thing - I thought the filter element would pop out of the plastic, but it's a single (expensive) manufactured piece.  Finding these is tricky.  You can find cheap, paper filters for about $40 a go, but I found the K&N on Amazon for $120CAD, so that's going in and getting cleaned regularly.  That should pay for itself within three changes.

I'm not in a place where I'm going to put the front end back together again and pop in the replacement LED when it comes in this week.  With the replacement carb from NCK Salvage in hand, I'm going to try and rebuild as much of the Honda as I can over the long weekend (it's Thanksgiving Weekend in Canada).

The Strange World of Dash Bulbs:

12v 1.7W wedge dash light is the warning light bulb needed for a '97 Honda CBR900RR.  These are hard to find - Canadian Tire was no help and the girl at the parts desk in Guelph couldn't remember the numbers for parts, so I gave up on trying to find them.  I want to buy locally, but with that kind of floor help, it just isn't happening.

I found LED replacement lights that should last better and use less electricity in the process on Amazon.

This light search led to a crash course in bulb sizing.  The dash lights on the CBR900RR are T-5 Wedge 12v 1.7W bulbs.  T5 means it has a 5mm base.  In this case they're 1.7cms long on that 5mm base.  The LED should be cooler, use less electricity and be brighter.