2 stoke vs 4 stroke maintenance cost

[White trash]

Having said that.....my 450 is as fast as my old KX500 (fact, another member here will vouch for that!), but heaps nicer and easier to ride.

Dunno if you mean me, but I still have wet dreams about that 5 minute ride on the RMZ on race slicks. Fuck me they're WICKED. The thing just never stops pulling (bit like me)

[sugilite:Me]

lol, nothing 'fresh' about me mate.

OI! That post was for MidnightMike
When ya get to 1000 posts here, you become a official forum whore

So those tears as you parted with the 500 were just Crocodile ones eh, had me fooled, your acadamy material for sure hehehe

I luv dat 500, it's got the knobblies on at the moment.
As soon as you can ride, come up to my rehabilitation clinic.
I'm surrounded by the largest farm in the southern HB and can ride it anywhere any time, and I have a 50 km gravel road loop where most times you do not even see a single vehicle. Did I mention it had a awesome 7km hill climb?
you know it's good for you, so let me know when ya ready....

[UrbanMyth]

woah, that intresting that the 4s are more to run then the 2s i dont know much about dirt bike riding and i wont pretend that i do lol.

[Wellyman]

Basically a two sroke can be easier to run , in the long run,but it costs alot when it all goes wrong. 4 strokes last a long time and are very expensive for a basic service, but in saying that I have been running my 230 for 2, nearly 3 years without a problem and haven't openened her up yet for valve check etc.
WM

[TwoSeven]

I disagree with some peoples theories on the cost difference between the bikes.

As far as I can see other than the engine, there is no difference between a 4-smoke and a 2-smoke (frame, chain, sprockets, tires etc) - so in that regards, the costs should be the same (assuming the usage is the same - which would be a given or you couldnt compare them).

Now, in the engine department a 2-smoke requires oil to be purchased as well as fuel, a 4-smoke doesnt. Rest of the oil in the engine should last about the same.

Plugs should be the same (given the same number of cylinders), and so should oil filters (and on dirt bikes I suspect both require air-filters changed just as often).

So - the only real difference is that a 2-smoke is going to require piston and rings where a 4-smoke usually doesnt. All other parts should wear just the same given the same usage.

Now, most of the bikes i've owned messed around with, are good for about 100k+ miles before the engine really needs anything doing to it. More often than not, mainly bearings and other loaded bits require replacing.

So, the question is - what is the cost of replacing piston and rings in a 2-smoke over 100k+ miles vs giving a 4-smoke a basic strip down at the 100k mark.

One cant compare racing or different usage models because that comes down to the level of tuning and required frequency of rebuilds. Trying to compare a bike thats built to run 500km on a race circuit to one thats built to run 1500 is going to be silly isnt it?

For those who are making general statements about bike type x costing more - I'd really like to see some numbers put up to prove those rather bold statements - I suspect they are probably comparing a $20k+ piece of the latest platic road bling with a $6k tank built for driving off cliffs.

edit: I like it when it displays the message "Posting quick reply - please wait"

[cheese]

Yeah but your 230 is more in lines with teh older style 4 stroke platform. the likes of teh CRF250 are is a higer performance platform, basically you are looking at teh same time for piston changes (if not it's only a 50 odd hour difference) and teh 4s bits are twice the price, twice teh moving parts. etc, etc.....

It's like compairing a high performance everyday car and a F1 car engine.

[Ixion]

Transmission oil in a two stroke only needs to be changed once in a blue moon, since it isn't contaminated by combustion by products. And you can use a proper transmission oil, since it isn't doing double duty. In my experience (and I've had a lot of 2 strokes and a lot of 4 strokes, though road bikes only) the oil costs works out pretty much the same, especially once you factor in that the two stroke has no oil filter to replace.

I think the biggest determinant of wear (and thus maintainance costs) is revs (assuming equal build quality and such like) . So it becomes hard to answer the question of what you are comparing with what. A 3000 rpm Harley with a RGV250 ? A 7000 rpm GT750 (they last forever) with a 19000 rpm ZXR250 ? And even if the peak revs are the same, how much is the rider going to want/need to rev it in actual use . GT750 has such low wear because in practice you seldom need to rev beyond 3000rpm.

Overall, wielding a very broad brush, I'd say that it is much of a muchness if you do your own work, and are thus just comparing parts costs. Differences are slight enough, compared with cost of fuel, tyres, chains etc etc that it's not worth differentiating.

I'd agree with the 100000 km figure, extra cost of one extra set of rings for the two stroke at 50000km is offset by the extra cost of camchain (and maybe valve springs , valves, guides) on the 4 stroke. If you're unlucky with the 4 stroke, it can be a fair bit more expensive . If we are talking the latest off road competition machines with titanium valves and goodness knows what other nonsense (what's wrong with good old cast iron, anyway), then the two stroke will be much much cheaper.

If you pay a dealer to do the work, 2 stroke will always come out well ahead, just beacuse if the labour saving. So quick and easy to do.

[MidnightMike]

As for maintenance between a RG150, and ZXR250, I'm guessing that with 4 pistons and a lot more complexity the ZXR would be a lot more expensive to maintain over a extended period.

You mean when the four stroke needs a rebuild or for other things??? because i have an opportunity to buy an rg150 but ive been told that they drink oil like its the worlds greatest beer.

[sugilite:Me]

Yes, I was just talking about motor rebuilds, as in 2 stroke vs 4 stroke.
As pointed out by others, the oil does really add to the day to day running costs, and 2 strokes are not known for being economical on gas.
Normally factories run those pumps pretty rich, but even leaning it out would not make a drastic difference to the cost of running it.

I guess you would need to check out the purchase price difference between the RG150 and 240 4 stroke 250 and see if it is worth doing?
I'd be suprised if a thread discussing such things has not already been started, so it may pay to try a search on the subject.

[Motu]

Going back to the original post I'd presume we are talking late model Enduro and MX bikes,and that means modern 4 stroke - my first reply was about new bikes...fuel,oil and a spark plug is all you'd use in each for moderate use in a year.But the thumper costs heaps more,for serious use they will change the synth oil every ride,that's more oil than the smoker will use....and for a mere mid season spruce up,the 2 stroke will just need rings and a powervalve clean,even a piston is cheap.But the 4 stroke will need possibly a chain valves and springs.Have you seen the pistons in these things? Like a Formula 1 piston,it's a wonder they don't flip over sideways in the bore.In no way are they anything like a good old XR250.

For a trail bike my DT230 makes as much HP as a 4 stroke twice it's size and half as heavy again,goes like a cut cat and hasn't been apart in nearly 30,000km - fuel,oil and a spark plug,change the gearbox oil,that's a years maintenance.

[TwoSeven]

I'd be interested in seeing the cost comparisons between say a single cylinder 4-smoke dirt bike and the equiv 2-smoke dirt bike.

[Sketchy_Racer]

I dunno about the oil factors.....

My KR used 700ml of two-S oil in 1000kms of riding.

$15 gas gets me 250kms. so around $60 for gas and $15 for a 1 litre oil.

1000kms = $75

now, my CBR 250 did 1000 kms and it cost $30 to every 300kms .

and oil needs to be changed every 10000kms with oil been $50

so $100 for a 1000kms petrol and $5 of oil costs.

$105 for a 1000kms on a 250 four stroke

$75 for a 1000kms on a 150 two stroke.

piston on the KR need to be done every 20000kms

at a cost of ~150 - 200 ??

with the extra money saved on the two stroke which is $600 over 20000kms
i can get a new piston kit for $200 and still have saved $400 by running the 150cc instead of the 250cc

Never worry about doing the pistons on a 250 4 cylinder, cause if it needs pistons its already fucked.

Same amount of riding, only a $400 difference after 20000kms.

Another factor to think about is the ease of the job.

Doing a piston change on a two stroke is a piece of piss and any joe blog can jsut about do one, heck even Ivan can do one and hes the dumbest red neck you'll ever see.

But Four strokes are harder and normally require a shop to do them, and take much longer and cost more for parts.

A Two stroke is cheaper in the long run any day of the week. But there are so many variables that it is impossible to judge them like that.


-RG

[cowpoos]

I've heard...dunno how true...that husberg 4st engines [larger ones 400cc+]are lower reving and there fore more reliable and cheaper to maintain than comparable bikes? has anyone heard this or know anything about them?
as I've been toying with the supermotard Idea....but it has to beable to do offroad dutie as well....and big KM's....as it will be used on farm duty aswell [I can see the heads nodding back and forth about the farm dutie coment...I use a klx300 as a toy/farm bike at the moment and its brillent....but I wan more and I want it to be easily road legal]

[Wellyman]

Dunno if you mean me, but I still have wet dreams about that 5 minute ride on the RMZ on race slicks. Fuck me they're WICKED. The thing just never stops pulling (bit like me)

The more posts of yours I read of yours the more sorry I feel for Riff Raff!
WM

[Bangbug]

Why not have the best of both worlds?
Supercharge a 2stroke?
Forget running oil in your fuel (why make diesel?)
Don't know why we haven't seen one yet (apart from i guess it'd be a bit bigger n all) Maybe they are looking to recruit test pilots? Oooh oooh pick me!

I've only ridden one 2 stroke.............. lordy they are marvellous. Suck a bit more gas though, the older ones are a bugger to find parts for though
New ones i have no idea, id love to have a zap on a new 250 2stroker...... just so i can feel the pain again :P
Now where did i put my pills????????