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...

Victory!

After a long wait the o-rings finally came in to the dealer.  I then ended up getting the wrong o-rings (it turns out Kawasaki has like half a dozen different o-rings in this carburetor).  Don't expect to show detailed pictures and get any help from the parts experts either.





With the o-rings and t-fittings in I was able to put the carb back together again (again).  But before doing that I checked the floats one more time (they were all good), and reset the pilot screws to factory specs.  As I was doing that I noticed that the needles were moving when I flipped the carbs.  A quick check of the diagram showed that the spring seat goes above the pin, not below it, which I'd done (quite embarrassing really - I was tempted not to mention it, but my mistake might prevent someone else's in the future, so humility - and humiliation - first).

With the pins and seats the right way around I put the carbs back together yet again.  Installing it is as big a pain in the ass as it ever was, with the fitting of airbox boots being a dark art.

With everything reconnected and double checked, the carburetors were ready to go.  I set the petcock to prime to put a lot of fuel in the empty bowls, hit the choke and turned it over.... and it started and idled properly!

As I used to do, I eased off the idle as the bike ran higher and higher as it warmed up.  After a minute I turned the choke off and it was idling at about 1800rpm.  I dialed back the idle speed to 1000rpm and it was running steady.

So far so good, but the issue was applying throttle - the carbs kept flooding, backfiring rich and then killing the motor, would that happen this time?  No!  It's alive, ALIVE!!!

This video below may be the most satisfying thing I've ever filmed.

I now have two working bikes in the garage.  This has been a long and frustrating process, but I've gotten the rust off some long unused skills.  I'm taking better organization, attention to detail and theoretical understanding with me as I move onto other mechanical projects.

http://tkmotorcyclediaries.blogspot.ca/search?q=concours+carburetor

If it hasn't been replaced, it's been thoroughly gone over.  One carb is complicated,
four carbs is a universe of complications!

Perseverance & Patience

Steady on, it's not that bad.  I shall persevere!

The never ending tale of Concours carburetors continues.  My most recent attempt was to check the fuel amounts in each bowl and then reinstall and test (I'm getting very quick at this).

Once again the old Connie coughs and backfires and dies on throttle application.  The removals and re-installations have upset the old connectors between the carbs, which have developed a gas leak, so the whole thing came off (again) and is now apart on the work bench (again).


I contacted the local Kawasaki dealer for

The plastic bits that connect the carbs have
become brittle and leaky.

parts last weekend, but they've been radio silent.  The parts I need were easy enough to find, but maybe 22 year old carb bits aren't sexy enough to warrant a timely reply.  Maybe I should have ordered them online, in spite of a number of magazines lamenting people's lack of support for local motorcycle dealers.  Had I ordered them online they'd probably have been here by now.  Instead I'm left wondering if I can even get these parts.

The goal now is to take each carb apart, double check float depths and ensure all the internal jets and such are properly installed, then it'll all go back together again with new connecting pieces and go back on the bike (again).  With any luck I'll get some sort of clue that I'm moving in the right direction.  That's been the most frustrating part of this process.  I make changes and there is no change when I fire it up.  Whatever the problem is, I haven't come close to touching it yet.  At least a fuel leak is an obvious and easy fix.

Any day now...

Motorcycle Carburetor Rebuild Part Eleventy-Seven (airbox boots)

The carburetor rebuild grinds on.  It took the better part of a week to get the airbox boots in, and when I opened the bag they came in I'd been charged for four but only got three.  I tried contacting Two Wheel Motorsports to ask if the fourth boot was sitting around there, but they didn't get back to me.  

The Concours uses two types of boots to connect the carbs to the airbox and one of the old ones still had pretty good flexibility in it, so I used the three new ones and the best of the old ones.

I tried for the better part of two hours to get the carbs mated to the airbox properly with the stiff, old airbox boots without success.  With my home-made hooked screwdriver (to slip the boots onto the intakes) it took about ten minutes of adjusting to get a good seal on all four carbs.  If you're doing an old carb rebuild, buy some new airbox boots, it'll save you a  lot of frustration and swearing.

The old airbox boots look rough, but the real issue is that the rubber has hardened over time and no amount of heat will soften them up.  The new boots were supple and easily went on the carb air intakes with minimal fuss and bother.

I pay for four and get three.  Fortunately one of the old ones was still pretty supple so I could reuse it.

Ten minutes and the carbs are back in place.  Get new airbox boots if you're rebuilding an old carb!

Parts on Order Makes me Stop & Consider

Over the Easter long weekend I've rebuilt four carbs and put them back together again.  Unfortunately they won't go back on nicely thanks to two decade old rubber boots, so they're on order.  It's nice to have a forced day off.

If you're ever rebuilding carbs on a ZG1000, and the airbox on it is more than ten years old, it's a good idea to get some airbox ducts (that connect the airbox to the carbs).  Supple, soft rubber is important when connecting these up.  I tried for a frustrating couple of hours to get them to join properly.  This is especially difficult when the inner boots are rock hard, even when warmed up.  Steve suggests new carb boots to cut down on swearing, he ain't kidding:

Sixty bucks and should be here by
Wednesday.

I contacted my local dealer and they can have boots here by Wednesday.  They're charging less than they are going for on ebay or online retailers.  Score one for my local.  Sixty bucks means less swearing and an easy install.  Wayne, the Yoda-like parts guy at Two Wheel, says you're lucky to get two decades out of a set as they harden over time and eventually split.

With the weather going sideways again, there won't be much of a chance to ride any time soon.  Hopefully this means I can get this odyssey finished and the bike back on the road by the time the weather clears again.

The airbox ducts/boots that need replacing - the old ones are not only beaten up, but they've gone hard.
Even putting heat on them doesn't soften them up.  Note the flat spots up by the airbox that show you which
way to turn the boots.

Heating up the airbox boots - but they're too old!

A big empty where the airbox and carbs usually go

This ordeal has me rethinking things.  My wife suggested I unload everything except the old XS1100 and buy a regular motorbike that is more dependable.  When I started riding I got a dependable bike that just needed some cosmetic work.  It was so dependable it was tedious.  Since then I've gone back in time and enjoyed the world of carburetion and two decade old rubber, perhaps a bit more than I wanted to.

I genuinely enjoy mechanics, but never when there is a time demand on it.  I've already missed three riding opportunities because of the stuttering Concours, and this irks me.  The idea of wiping the slate clean and moving forward appeals.  I started riding late and moving through a number of bikes seems like a way to catch up on my lack of experience.  Maybe it is time to put sentiment down and move on.  I didn't start riding to watch the few lovely days we have in a too-short riding season pass me by.

A Tiger?  In my garage?

The little Yamaha and the KLX are gone now, netting me about $3000.  As it happens, a 2003 Triumph Tiger is available just over an hour away for about that much.  Come the end of the week I might be able to say, "a tiger?  In my garage?  Must have escaped from a zoo!"

Icy Days & Carburetors

It's been ice-storm icy here

Without warm weather beckoning (we've been in the middle of an ice-storm here) I'm in less of a panic about not having a bike to ride.  With an extended long weekend thanks to power failures and such, I've been hammering through four carb rebuilds.

The K&L kit I got came with a new bowl gasket, new pilot jet, washer and o-ring, and a new float jet.  Breaking down each carburetor one at a time (so I don't mix up parts), I cleaned out the carbs and blew them out with compressed air and then put them back together with the new parts.

Those little rubber bits
get crusty after 22 years
on a bike...

Adjustment wise I reset the float height (17mms with the float unweighted - held sideways).  I also reset the pilot jets to two turns out from snug.  The pilot jets varied from almost five turns out to under three turns out.  I'm curious to see how this affects fueling.  The manual suggested resetting them to what they were, and I did record them, but the factory setting is 2 turns from snug, so that's what I reset them to.  I'm not sure why I'd reset them to what they were when they weren't working well.

The carb rebuilds weren't particularly difficult, but they were a bit tedious (you're basically doing the same thing four times).  Things have ground to a halt again as I've found that I need o-rings to replace the old, broken ones that sealed the fuel lines between carbs.  With some new o-rings I should be good to put them all back together again and re-vacuum tube them with new tubing.

Rebuilding the first carb - it took a bit longer as it was more exploratory

The second videos hows the final two carbs and then discovering the need for o-rings -both videos are based on photos taken every 10 seconds compressed into a video running at one photo every 1/10th of second.

As an aside, I thought it would be a good idea to go through Motorcyclesuperstore.ca, but they seem to have pulled back from offering Canadian customers a clear view of their prices.  You used to be able to buy in Canadian dollars and there were no surprises.  When you buy now they charge in U$D, so you've got to do some math to figure out how they compare to Canadian retailers.  It looked like they came out about twenty bucks ahead of an equivalent Canadian order, until I got the COD message with border taxes.  Suddenly that twenty bucks turned into paying an extra ten.  I liked motorcyclesuperstore.com, their customer service went above and beyond, but their lack of clarity around pricing of orders to Canada puts them in the same category as any other US distributor.  I'm not happy with canadasmotorcycle.ca's 'easy' returns (they charge you for shipping), but I'm not playing roulette with customs costs again.  I'm afraid that's the last time I'll use motorcyclesuperstore.  I need to start looking into other Canadian based motorcycle retailers.

Two down, two to go...

The pilot jet (centre) - has a spring, washer and o-ring underneath.

The float bowl off and being cleaned out - the floats are held in a pin at the bottom - the float jet hooks on a tab in the middle

Carb Photos:
https://goo.gl/photos/kPhLXuQnb8HmdQFs9

Concours Carburetors: Prepping for rebuild

There are three rails holding the four carbs together on a Kawasaki ZG1000 Concours.  Two of them are structural and the other one holds the choke mechanism in place.  Taking them off a twenty two year old carburetor can be trying.  I ended up having to cut a line in one of the retaining bolts and put some heat on it to get it to let go, but all three pieces are out now.

With the four carbs separated I'm now waiting on the rebuild kits.  When they arrive I'll rebuild each carb one at a time (so I don't mix up parts).  All four carbs are cleaned up (a touch of carb cleaner and a toothbrush got 22 years of grime off) and awaiting some new gaskets, float adjusting and rebuilding.  While in there I'll make sure the needles are in good shape and everything has the right geometry.

The first one will be exploratory and slow, by the fourth one I'll be able to rebuild these things in my sleep!

The four carbs separated and cleaned.   Taking a twenty two year old carb apart takes some patience, and some heat.

Cleaned up and ready for a rebuild.

No lost parts this time - everything labelled and organized.

The choke rod (up and down to the right) partially removed - each carb
links to this plate which moves them all when the choke is pulled.

It only takes a bit of carb cleaner and a tooth brush to get the crud off. I blew it dry with the air line afterwards.
Caustic carb cleaner (it melted two pairs of latex gloves - for goodness sake, wear gloves!) isn't recommended on the insides
- I'll use a bit of gas and a clean toothbrush to make sure the innards are perfect when I get in there.

Some Kawasaki Concours ZG1000 carburetor links:

https://snapguide.com/guides/rebuild-kawasaki-concourse-carbs/
https://sites.google.com/site/shoodabenengineering/intake-and-exhaust
http://www.murphskits.com/product_info.php?products_id=130
http://www.randols.net/Connie/#_Toc276312906

Pulling the Carbs

The Concours' carburetor has become cursed by demons.  These carbs tend to not come back from sitting very well, though last year they didn't have this problem.  When I put them away they were running well, but no longer.

Yesterday I pulled the tank again and went over the vacuum tubes in detail - no breaks, no problems.  After putting it all back together again I took it out and had the same hesitation on throttle and back firing.  The bike feels seriously down on power too.

I was hoping to send the carbs down to Shoodaben Engineering in Florida for a spa session with Steve.  His prices are more than fair, but after having an economist (whatever the hell that is) as a Prime Minister for eight years, Canada's dollar is in the toilet and my $500US carb repair would cost north of $800 with shipping, customs and the exchange rate.  I paid $800Cdn for the bike in the first place.

So I'm rebuilding carbs!

In spite the many terrifying stories of carb removal on a Concours, I found the process pretty straight forward (thanks to Steve's video).  Warm up the rubber on the airbox to carb, they get nice and soft, and you wiggle the whole thing free.  With the carb on the bench, parts are ordered ($200Cdn for 4 kits - 1 for each carb) and I'm beginning to break it down to rebuild each.