TRAIL ZONE

ASK DR PHIL:

COMMENTS ABOUT TWO-STROKE FUEL ECONOMY?

I’ve just finished reading and watching your latest issue and DVD and if I had to advise you on any changes to the mag, it would simply be: “Don’t change anything!” I read with interest Dr Phil’s Smoking Guns article, as I have returned to the ‘dark side’ having recently purchased a new 2010 KTM 300EXC. After owning a 450EXC for six years, I thought I might throw in my two cents worth having now done 1,000km on this ripping beast of a bike. The first thing is, why did I go back to a two-banger? There are four reasons: 1). As a time-poor mid-40s type, the idea of no more valve clearance checking and adjusting plus two oil filters has a lot of appeal; 2). After a 10,000km top-end rebuild, every noise from the engine (good, bad or otherwise) stressed me; 3). Riding my son’s Gas Gas 200 through Latrobe state forest on numerous occasions and loving the nimble little rocket; 4). $2,500 left in my pocket at the end of the purchase. So how could I, or anyone, go wrong ? Well if 70 or 80km between fuel stops is the norm, all is good and you should enjoy your time at the top of the hills waiting for your mates! However, if it is more like 80, or upwards to the occasional 200km mark, or even 80km in the sand, you have a problem. So here are the facts: the 12.5-litre long range tank on my 300 will get me around 120kms of High Country fire-trail fun. My mate’s 450 ’Berg will go 130km on seven litres on the same trails. When we stretch it to 200km, five litres in a fuel bladder has the four-stroke rider happy, whereas I’ll need eight – and I’m nervous, overweight and cumbersome for the first 80km and still don’t know if I’ll get to the next fuel stop before running out! The motto with fuel is: ‘better to be looking at it than for it’, so anything over say 115km and I have to carry fuel, even with my bigger tank! Conclusion: my weight advantage is gone at least at the start, as I’ve seven kilos more fuel on at least, plus ongoing fuel range stress. Extra work in the shed (with four-stroke issues) is so much easier to deal with than stress on the trail. Now, everything you wrote in your Smoking Guns article is totally accurate and I’m not about to sell my 300, but ... like many other Aussie trail riders, 115km between fuel is the norm and on that alone, if I had my time over, I’d get another four-stroke. All the best for the new year guys and keep up the brilliant work.

-- Andy Broberg, via www.trailzone.com.au

Thanks for your feedback on the mag and our technical editorials, Andy. There are oh-so-many riders in exactly your situation, as two-strokes certainly are more thirsty than thumpers. Maybe you need to consider an even larger capacity accessory-brand fuel tank? Or perhaps one two-stroke AND one thumper in the garage might be the answer so as you have all the bases covered ... but alas, we can’t all be plumbers for a living!

-- Dr Phil, www.trailzone.com.au