2 stroke touring
 

Hey hubbers!

It's been a while since I last posted, been a bit busy and whatnot. Finally sold the Triumph Tiger off (pheeewww!) and a set of events got me buying a 2 stroke Kawasaki (kdx250) dirt bike a couple of days later.

2 stroke is a new things to me and I'm still getting used to the idea of a bike with no on-board electrics, kick-start, wildly high revvs, nimble weight and crazy acceleration.

Now, the take home message I've got from this forum is that everything is possible and any bike can do any trip, if ridden right, maintained well and common sense prevails. However, discussing the potential of a long distance stint on the KDX250, friend telling me that the engine will burn-out/jam-up if ridden for a long time.

I just need some validation from someone with some experience with 2 strokes and touring to tell me whether this is true or not, prior to me spending lots of time/money/effort on modding this bike for next summer.

So over to you guys, cheers!! :thumbup1:

I asked if people had done this a while ago, I definitely wouldn't recommend it personally as they seize, foul plugs and tear up tires. A 250cc needs a new piston every 30 hours or so competitively, I would say approximately 50 hours to be safe, if you put it off then it will seize and scratch the bore you will be up for heaps of $$ (been there :thumbdown:). The KDX is a strong, powerful and cheap forest rider though, you won't regret owning it if you keep up with the maintenance but it's not made for long trips (the vibration would get to ya too).

I've personal toured on a 175 two stroke .. with me the engine did 20,000 miles from new .. orignal bore and piston and I traded it in .. the sales guy said it was a very strong bike engine wise and asked what rebore it was on .. he was amazed.

That said I've no personal knowledge of the kdx250 so cannot comment more ..

The only problem I found tourning with the two stroke was finding two stroke oil..

Back in the early '90's I put 20-odd thousand miles on an MZ in a year. It was a mixture of London Traffic and full throttle motorway runs back home. It broke down once, way less than the BMW that replaced it. Yes it can be done, although I would say that MZ was a particularly good example.

The trouble is, you are running a highly strung motor basically designed to wring the last HP out of the capacity. Keep it tuned, use decent oil and go at the pace it's happy with and they work. Get anything out of whack, or misuse it and rather than a bit of wear, you get destruction. If you can detect weak mixture by the smell of the exhaust and can take a head off for a decoke/piston change in your sleep go for it. If not there are other bikes you might be happier with.

You also have the issue of fuel. The MZ could turn in less than 40 MPG at times, the BMW F650 averaged 60 and there was no need to go hunting supplies of oil.

Andy

Hey guys, Thanks for your comments, I posted a similar query out on thumpertalk to see what the overall view was. I think I made a slight error of judgement on 2 strokes. I thought the only difference between the two was how the engines run, hadn't factored the other variables (that I wasn't aware of) into the equation.

However, I like this bike, it really is a fun thing to ride, it's reliable (starts with 1-2 kicks) and simple (mechanics that a child could do), worthless (making it not a theft trap), and a great conversation piece when parking up in the centre of london (covered in mud with nobblies)... and did i mention nothing on the insurance?

Anyhow, with the left over money from the Triumph sale I still can buy another bike, I'll keep the 2 stroke as a back-up bike whilst I'm doing-up whatever the next bike is for my trip next summer.

As a certain Mr Pirsig would put it: this bike is a "gumption"-full bike, even if it makes no rational sense to others, it's worth keeping.

Neil, ignore the negative comments here and stick with the two stroke. The facts are that I spent two years on the road on my Yamaha RD350 (2 stroke twin road bike) in the mid-late seventies.

The RD was the proverbial pocket rocket of its time and I used to race mine locally (at Philip Island) before I stuck it on a ship to Singapore, rode it two-up to Europe, around Eastern Europe and then down through the Sahara to South Africa.

By the time I replaced the pistons (fractured due to sucking in water on a river crossing in Kenya) I had covered over 40,000km - which equated to around 700 hours of riding. I leaned out the jets to improve fuel economy and averaged 5l/100kms (56mpg) and she would run on anything - even on kero in Africa!

Lightweight (well before I loaded all the crap I carried on her), reliable, easy to repair (I tore down the motor in a hotel room in Nairobi with only a shifter, allen key, set of pliers and spark plug socket - I'd lost all the other tools in that infamous river) and great fun to ride.

I still own the old girl - she's been sitting in my shed now for 30 years.

Garry from Oz.

farqhuar, I'm greatful to your response. However, the kdx finished her first tank of fuel off yesterday (since i bought her) after 156km which is 96miles on a tank of 10 litres (~43mpg), which is as bad as the triumph tiger was.

Ignorantly, I had thought that being a 250 i'd be getting about 70mpg, (should of known that 2 strokes are not the same) I also hoped that somewhere online i'd find somewhere where i could find mods like a larger tank, change of seat, etc. Sadly, there isn't much hope for me.

However, she's a great ride and I'll keep her.

I'm very curious about leaning out the jets. Carbs were the things that got me to fix/build my first rat bike and also the thing that made me give up on it after many many hours of fun and frustration. I haven't touched a carb ever since then, as I clearly don't know what I'm doing when it comes to fuel to air mixes.
(so what's the secret?)

Also, wouldn't thinning the jets cause engine damage/jammage?

You can buy smaller jets or just feed wire through them but to be honest on an enduro racer I don't know why you would choose fuel efficiency over power, in fact you should be using it to do jumps, wheelies and hill climbs! Maybe get some motard rims for it if you're going to commute, that'd look pretty sweet, like this one I found on google image search:

http://homepage.mac.com/gerg7836/.Public/KDX-SM.JPG

Like Farqhuar I toured a lot on 250 / 350 two strokes back in the 70's and we always got around 50mpg. When I started looking at larger 2Ts - Suzi GT500 /550 / 750 etc the mpg was down to around 35 - 40 and it pushed me into looking at four strokes. The H1 500 Kawasaki I still have only does 25 -30mpg - less than my Land Rover!

A few years ago I looked seriously at a Honda CRM250 (a 90's 2T trail bike for those that don't know) as an lightweight overlanding bike but the need for decent 2T oil (in the middle of Mauri?) and rising fuel costs killed the idea.

Regarding 2T longevity, I used to recon with the 250s that by about 15000 miles you'd notice the top end power dropping off and at around 25000 you'd need to do something about it. If you'd had to use car oil in place of 2T those distances came down a lot as you'd gum up the rings. The bike would still run but it would be harder to start and make no top end power. Cranks were only good for about 25k (and expensive to rebuild) as well but I don't remember ever having a gearbox or clutch problem.

The biggest problem with 2T touring though is peace of mind. The risk of seizure was ever present even with the hi tec (then) Japanese autoposilubes particularly if you did long motorway sessions at high speed eg German autobahns and I always rode with one ear listening out for engine distress and two fingers on the clutch lever. Riding along reciting the bikers prayer - "Please God don't let me break down" was a kind of early 70's ipod substitute. Modern synthetic 2T oil gives a much greater margin of error and non slip solid state ignition systems means not having to sit with a degree disc or dial gauge in a Greek campsite trying to compensate for points wear.

I raced two-stroke enduro bikes for years. The big drawback is frequent piston changes but as long as you get your head around this being a simple servive part (like changing brake pads) it's cheap, simple and not a big deal.

In fact you can easily do a top-end rebuild on the roadside and with minimal spares and tools you could bebuild the bottom end too. In fact you could carry enough in the way of spares to replace the entire engine if you really wanted.

For ease of maintenance they're unbeatable.

Cheers for your response Bronze, I have however bought the DR-Z 400 SM that i have been longing for, for a pretty penny and now I'm left with what to do with the KDX, I've not touched it in weeks. Perhaps take it to some fields I guess.

Two stroke touring
 

In 1956 Michael and Nita Marriott rode a new, 150 cc. two stroke NSU scooter two up from England to Australia. The engine design probably dated back to the 1940's, there was no automatic oil mixing and they carried a fair amount of stuff. The little machine transported them through Afghanistan at a time when there were virtually no decent roads, ground its way through multiple mountain passes, crossed deserts and arrived in Kabul with the engine quite intact and essentially problem free. The right two stroke can apparently tour.