Tag Archives: Suzuki

Track day tribulations

I keep assuring you, my dear readers, that I am not a mechanic. It is about time I write a post that helps illustrate that point.

The last track day I did on the RGV was not the biggest success. The bike was failing to accelerate in the top gears and by the “seat of the pants dyno” was even a little weak in the lower gears. Apart from some cursory inspections and a new set of spark plugs, I hadn’t really done much on the bike since the previous track day, so it was not much of a surprise.  I can’t even say “I should have known better”, because I do know better… As they say: “Proper preparation prevents poor performance”

Anyway, both the bike and I survived the day, so back at home, it was time to work out what went wrong… It didn’t take long – the left carburettor float bowl was leaking fuel. Put simply, the top cylinder was unable to get the fuel it needed when running at full throttle.  The float bowl o-ring had a gap if about 3mm, through which the fuel was able to escape.
Where the carburetors are situated, meant the fuel leak was relatively safe.  The fuel would fall on the crank case, which was hot enough for most of it to evaporate off.

The reason there was a gap in the o-ring was no mystery: I had cut it. Of course, I hadn’t done this without a good reason. At a previous track day I had to take the carburettor apart to clean one of the jets that had become blocked. The o-ring had stretched and no amount of careful prodding, cussing and holding my mouth correctly was going to get the o-ring to fit. One truism of track side maintenance has always been “No matter what spares you have with you, you’ll need something you don’t have.” Faced with the choice of “go home” or “improvise” I chose the latter and cut a small section of the o-ring out.

Why did the o-ring swell? Truthfully, I do not know.  I am guessing it reacted to something, but I could not correlate what the Internet tells me and anything that I remember doing.   I think I may have fitted the o-ring with some rubber grease, but that is designed not to react with it!  Most likely, I got some carby-cleaner on the o-ring and it  reacted to this, although I don’t know for certain.  As I had now discovered, it eventually returned to its normal size, thus leaving me with a gap.

Whilst on the matter of mechanical confessions… That day, when I refitted the carburettor, I broke the thread of the plastic choke nut. These are hollow, allowing the choke cable to pass through them. As a result they are incredibly easy to over-tighten and snap. Without it in place a lot more air would be drawn through the carburettor, causing the engine to run dangerously lean.

Plastic choke nut assembly

There was insufficient thread left on the choke nut to hold against the spring tension, but another RGV owner came up with a clever way of using cable ties to hold the choke nut in place. It was certainly a bodge job, but it easily held up on the day.

So, what did I learn from my mistakes? Lots of things, really!

  1. Do your preparation before the track day, not at it.
  2. If the manual doesn’t suggest using sealant or other consumables, then you probably shouldn’t.
  3. A twenty-four year old bike that you thrash when you ride it needs plenty of TLC/maintenance when you aren’t riding it.
  4. A post track day inspection and service is a good idea.
  5. If you can’t have the right spares with you, at least have plenty of cable-ties!

 

Time to end the RGV restoration

I have recently come to the conclusion that it is time to put an end to the project of re-building / restoring the RGV.  Don’t worry, this story has a happy ending!  My decision is not to give up on the project, but to finish it.  Discuss Project management for long enough and eventually you will end up talking about the three competing factors on any project.  The saying goes “Features / Timeframe / Budget.  Choose two”.  Although most of my experience with project management has been with software, the same idea applies to any project. – The RGV restoration would be no different, except for the fact that I had allocated a monthly budget of what I was prepared to spend on it.  This makes the budget a function of how long the project runs for.  So, this unnaturally skews the balance of the three competing factors. Unfortunately, it also makes for a long project!  I could have spent more each month, but I have seen too many motorcycle restoration projects run out of enthusiasm due to the large money pit that they can become (and no doubt how quickly in debt their owners can become)

Speaking of large money pits…  I kept a spreadsheet to allow me to stick to my monthly budget.  This in itself seemed like a wise idea.  It does however put sharply into focus how much money I have poured into the project.  (Should that be “poor-ed”?)  Given the prices that RGVs demand these days, it is suffice to say that I would be making a loss if I sold the project at this point in time.

In terms of where the bike is “currently at”:

  • It is still two packing shelves full of pieces.
  • I have recently had the front forks and rear suspension rebuilt.  This was only the second time I have used a commercial business to do any serious work.
  • I have sourced all the parts and I am in the middle of rebuilding the brakes.  That process will hopefully be a story for another time.
  • About the only outstanding parts left to purchase are new chain and sprockets and new tyres.  (For some reason I just don’t trust twelve year old tyres…)

Things I have learnt along the way:

  • I should not have attempted to restore this bike.  Despite starting with a “free” motorcycle, this project has cost a fortune!  It would have been cheaper to buy a running and almost road-worthy RGV and start from there.
  • By doing the boring things first (such as frame straightening) rather than the fun things (such as painting fairings and buying bling parts) the restoration project didn’t start with a bang and run out of momentum.
  • Some planning would have avoided the need to do things multiple times.  – I had to completely strip the bike to get part of the frame repaired.  I subsequently put the swing-arm rear suspension back on, only to remove the rear-shock to get it serviced later.
  • Buy good tools.  They really do make the job easier.  On the other hand…  Some once-off style jobs are not worth spending a fortune on.  Sometimes it makes sense to take the part to a workshop where the job can be done for you.  Removing the bearings from the rear-suspension linkage was a good example.
  • I have become quite good at watching where things (such as nuts / bolts / washers etc) go when I drop them on the ground.  This is an under-rated skill in my opinion.

One thing which I don’t need to learn is that this isn’t the end of spending money on the bike.  A track-bike is never finished and rarely cost free. Until I get the chance to properly put the bike through its paces, I don’t know if the gearbox is mechanically fine, whether the clutch plates slip and whether the engine will perform properly under load.  All these things will reveal themselves in the fullness of time!

Off Road

I have an admission to make.  I have been riding motorcycles for over sixteen years and (at a rough guess) around a quarter of a million kilometres.  I have ridden many different bikes and also raced motorcycles at a club level.  My admission is, until the last few days I had never ridden a dirt bike.  Thanks to my brother-in-laws, this is now something I can add to my riding experiences.

Unlike some other road-riders, I was under no false-illusion as to what I would be like on dirt.  Apart from knowing what controls did what, my experience counted for little when it came to riding dirt.  These days I try to avoid taking road bikes on dirt roads.  I have got all the excuses under the sun as to why, such as: A lot of modern bikes have become too “single-purpose” to do dirt roads well / The big wide tyres of a road bike tend to skate around on a dirt surface / It takes ages to clean them afterward.  Basically, I would rather just try and avoid it.

The one warning I continually got about riding dirt bikes was that you just can’t grab the front brakes to stop.  This well may be true, but used correctly, the front brake is very useful.  Maybe some road riders tend to be more boisterous with front brake application than I am, because after some time I became more relaxed with using the front brake.

As for my actual riding on the dirt, I was predictably crap to start off with.  My road-riding bias meant I was unable to comprehend how the long travelling suspension of the bike could handle the deep ruts in the track as well as they could.  I had a couple of low speed “step-offs” when dealing with steep and rutted four-wheel drive tracks (both uphill and down) In retrospect, it was my lack of speed that got me in trouble far more than going too quickly.  I don’t think I have ever had the attitude of being ten foot tall and bullet-proof and going faster in a situation where I didn’t feel in control was the furthest thing from my mind.

I did see noticeable improvement in my riding as the day wore on and finished the day with some descents and a hill climb that I was proud of – whilst still being acutely aware of how remarkably simple they would be to someone with more riding experience.   Despite slowing them down, my riding companions patiently waited for me and offered encouragement.  I would have loved a few more riding tips, but they probably did the right thing by not overloading me with information to try and apply.

My faithful bike for the day was a Suzuki DRZ400 – complete with electric start. (A feature I was quite thankful for!) The torque of the 400 single cylinder meant it would chug along quite happily when I left it in a gear that was too high for the situation.  More accomplished dirt riders may have found some fault with the bike, but to me it seemed just about perfect!

I doubt my single day’s ride has made me a better road rider.  I don’t think I reached any great levels of competence from my day in the saddle, but it was great fun and a real eye-opener for me.  Whilst I am not about to rush out and buy a trail bike for myself, it has gone on that list of things I want to do again some time.  When “some time” arises, hopefully I will have remembered what little skills I have gained and forgotten how stiff and sore my legs were the next couple of days after the ride!

RGV Update

“Good news everyone!”  The RGV’s engine officially works.  The reinstallation of the engine took far longer than planned.  That was due to a combination of intentional stalling to get the budget back on track, unplanned extra work due to faults discovered along the way and limited spare time.

When I went to install the engine back in the frame, I discovered a hairline crack in the engine cradle.  Although the engine has rubber mounts reducing the amount of vibration transferred to the frame, common sense dictated that I should not ignore such an obvious weak point.  A quick trip to a local aluminium welder had that problem sorted out.

During this time, I took the opportunity to superficially tidy up the expansion chambers.  (exhaust pipes)  I say “superficially”, as I made no attempt to reduce the carbon build up that is surely deposited on their insides.  Instead, I sanded back the existing layers of paint, removed as much of the surface rust as possible, treated the remaining rust with a “rust converter” and treated the pipes to a fresh paint job with heatproof paint.  Whilst being a “far from perfect” job, it should give the pipes a bit more protection against the elements.

The reinstallation of the engine, exhausts and cooling system went remarkably smoothly, given that I do not have a workshop manual.  I have yet to buy myself a workshop manual for the bike.  This is largely due to the fact that I used to have one and they are not cheap.  I cannot quite bring myself to buying a new one.  These days, “bootleg” PDF versions are available on the internet.  I have found the PDF version of the RGV manual to be an incomplete series of bad quality scanned in images.  Still, using this and referring back to photos I took of the bike at the beginning of the year meant I did not end up with “bits left over”.

Once it was back in one piece, half a litre of fuel and the battery were “borrowed” from the VFR, and I was able to fire the bike back into life quite easily.  The “build” itself still has a fair way to go.  The high-level short list comprises of:

  • Replacing the brake lines and servicing the brake calipers
  • Front fork rebuild or replace (to be decided based on pricing)
  • Replacing various bits and pieces that are worn out. (chain and sprockets / clutch lever and cable / etc)
  • Fitting the new bodywork.  But that’s a story for another time.