2 stroke vs 4 stroke cost of maintenance?

[ntrue505]

HI, I have always been a fourstroke fan, because it I like the bottom end torque and I have always been told that they will last much longer. Lately though, I have been searching and digging to find the best dirtbike for me, as I am in the market, and in nearly every video I watch of a 2 stroke, something gets said about a 2 stroke being easier/cheaper to maintain. In my experience, a 2 stroke has to be rebuilt every 2 or so seasons, (regular riding, not racing) while a fourstroke will last 5-8 years no problem. Could someone please clear this up for me? Thanks in advance!

[Bob_N.]

Hope this will shed some light. Two strokes do require pre-mixing, and making sure the jetting is right or you can foul plugs or eat top end parts. I got in the habit of just doing a top end on my past two stroke every year. I now ride a four stroke (four cycle depending on who you talk to). I have yet to put a top end in it, I check the valves regularly and change oil frequently. I my opinion I feel the four strokes may cost more up front but should last for several years unless you are a pro level racer and live running on the rev limiter. Hope this helps.

Bob

Edited October 27, 2012 by Bob_N.

[ntrue505]

I am pretty mechanically savvy, so I can work pretty well with stuff. So If the mixture/jetting is done right, and it isn't constantly over revved, how long would say a yz 125 last?

[Bob_N.]

I rode a KX250 for several years. Since most newer two strokes have plated cylinders I always rebuilt the top end to save the cost of replating or replacing the cylinder in the event of ring wear or piston destruction. I learned the hard way. With a 125 two stroke I would not go more than two yeas without a top end just due to the high revving nature of the engine. A newer 250F (KXF, CRF) would hold up better long term compared to the 125 two stroke. Yes there are horror stories of them eating valves and such, but most of those again are riders hitting the high RPM and banging the rev limiters in the air.

[ThumpinAway]

A yz125 will be way less maintenance and cheaper also. With a yz250f, you should replace the cam chain every so often as well as the piston and rings. Also once your valves need adjusting, after a few times you'll need to replace them,get the seats cut and the cost of that will be equivalent to 5 years of top ends on a 2 stroke. There is a lot more on a four stroke to go wrong,and all the parts are a lot more on a four stroke.

Edited October 27, 2012 by ThumpinAway

[shawn1331]

I am pretty mechanically savvy, so I can work pretty well with stuff. So If the mixture/jetting is done right, and it isn't constantly over revved, how long would say a yz 125 last?

At least a full season if it's ridden farily hard and maintained right. You'll know when it needs a rebuild because it won't be as powerful, and it'll sound different. possibly might burn oil too. But an entire engine can be put into a 125 for under $500 cdn. Thats with ebay parts and what not but it can be done.

[The Spanky]

I am pretty mechanically savvy, so I can work pretty well with stuff. So If the mixture/jetting is done right, and it isn't constantly over revved, how long would say a yz 125 last?

It depends on a lot of variables. Riding style, amount/quality of pre-mix oil, maintenance, average loads, average rpms...there is no rule.

The one year that I raced a 125, my top-ends lasted about 15 hours. Of course that was back when I was still fast enough to be able to push a bike for all it had.

[jason white]

If they are maintained like they are suppossed to be they are both some what lower cost in maintenane. jetting,oil change,clean air filter lube bearings,etc. More preventative than corrective maintenance.

I ride two strokes because of the lightness and easier to restart when I am in the woods. I can do a entire motor cheaper on a 2t than 4t. Also two strokes runs cooler at low speeds. Theres pros and cons of each but I have learned to love the two strokes in the woods. I dont like checking and adjusting valves. Either way its an exspenive hobby.

[nickjpass]

Two strokes are cheaper...want proof...here's some unreliable proof lol

Read the description of YZ250 from yamaha-motor.com below ?

[DMC707]

It depends on a lot of variables. Riding style, amount/quality of pre-mix oil, maintenance, average loads, average rpms...there is no rule.

The one year that I raced a 125, my top-ends lasted about 15 hours. Of course that was back when I was still fast enough to be able to push a bike for all it had.

Yes, and if you were a B class rider or above, 15 hours even was probably stretching it thin . I would re-ring the 125's at 10 hours or so with complete top ends between 15-20 hours------

Lest anybody thinks that is insane, -- that is actually a lot of race hours --- especially if you have a practice bike (and when bikes were $3500 each, it was easier to keep 4 bikes per season than it is now that bikes are 10k apiece after they are sorted out) -- 15 hours on a race bike is basically 15 race days, which could be 2 months if you race a lot, or 6 months if you don't -- either way, its not an insurmountable sum of money to keep them up, but can get expensive

I guess i cant really speak for the 250-F's reliability because i've never owned one, --- ridden a few though. My 450's over the years have been good for many more hours between top end fresh ups than equivalent 250 2 strokes though-- you do have to check valves and clearances periodically though ---- ps - my 4 stroke experiences so far have been strictly Yamaha YZF's though , i wouldnt wish a suzuki or kawi on anyone without deep pockets or a profound sense of humor though

even in the 2 stroke days, Suzi's and Kawis were shit --- i went through 8 RM 125's and 250's in 1991 , between broken frames, footpegs being torn off, broken engine cases, and in one case, a brake caliper that snapped in half mid-race, plus bottom end seizures on bikes with 20 hours on them, i would say Suzuki 2 strokes are the absolute most expensive bikes i have ever owned, --- but back then if you had the results, their contingency program would basically be like another sponsorship that would help you buy parts for the POS's --- the poor 2nd owner would get a 3 month old bike that would borderline be ready for the boneyard, --- but then again, may last a few more years for a trailrider or pasture cruiser

Edited October 29, 2012 by DMC707

[The_Vernsker]

It really depends on how long you plan on owning the bike. Here is the best example i can think of:

If you were to buy a brand new 2stoke and a 4stoke at the same time and put the same amount of hours on them (lets say 40+ hours per year)......

1) the first 2 years the 4stroke would be cheaper to maintain.

2) after 2 years the 4stroke would need a major top-end rebuild causing the 2 stroke to be cheaper after the end of 2 years of riding.

I calculated this by looking at cost of maintenance and manufacturer's recommended service intervals. I have also experienced this myself, it is a good rule of thumb as long as you aren't an A class rider who hits the rev limiter constantly.

A few things to remember are that: The expensive part about 2strokes is replacing the piston and rings. But 4 strokes need oil changed often, filter kept very clean, and checking/ adjusting the valves is time consuming and expensive if done by the dealer. I do all the work to my bikes on my own and i can honestly say for every hour i spend working on my yz125 i spend 3 hours on my kx250f and kx450f.

If you plan on buying a used bike a 2-strokes tend to be cheaper in the long run. If you accidentally buy a four stroke that needs a rebuild you could be looking at 1200 bucks just for the parts.

Edited October 29, 2012 by Vernsker298

[DMC707]

It really depends on how long you plan on owning the bike. Here is the best example i can think of:

If you were to buy a brand new 2stoke and a 4stoke at the same time and put the same amount of hours on them (lets say 40+ hours per year)......

1) the first 2 years the 4stroke would be cheaper to maintain.

2) after 2 years the 4stroke would need a major top-end rebuild causing the 2 stroke to be cheaper after the end of 2 years of riding.

I calculated this by looking at cost of maintenance and manufacturer's recommended service intervals. I have also experienced this myself, it is a good rule of thumb as long as you aren't an A class rider who hits the rev limiter constantly.

A few things to remember are that: The expensive part about 2strokes is replacing the piston and rings. But 4 strokes need oil changed often, filter kept very clean, and checking/ adjusting the valves is time consuming and expensive if done by the dealer. I do all the work to my bikes on my own and i can honestly say for every hour i spend working on my yz125 i spend 3 hours on my kx250f and kx450f.

If you plan on buying a used bike a 2-strokes tend to be cheaper in the long run. If you accidentally buy a four stroke that needs a rebuild you could be looking at 1200 bucks just for the parts.

that sounds pretty accurate

[dhdrider]

It's also dependent on the size of 2t and the type of riding/racing you are talking about. I would argue that most of the chatter you hear about 2t bikes being cheaper to maintain is coming from guys that run 2t bikes for trailriding/enduros/harescrambles. The ease of maintenance of a 2t really comes into play for bigger bore 2t bikes (250-300cc). Guys that run a 250 or 300 for trail riding and the occasional enduro or harescramble can get MANY more hours out of a topend than the hardcore mx'er or harescrambler. I have 130 hours on my topend and have no plans to change it anytime soon. My brother just rolled 300 hours on his KTM 300 on the original topend on his bike. I trail ride every week or 2 and race an enduro or harescramble about once very 4-6 weeks. I'm not a pro by any means, but I'm not really slow either.

Edited October 29, 2012 by dhdrider

[ntrue505]

Well, basically the way I understand it, is yes a 2t is easier, and cheaper, but in a way they are sort of a ticking time bomb. Although they may be cheaper, you never know how often you will be spending time and money on them. Also, I wouldn't be racing, mainly trails, and nothing near what the hardcore harescramble guys put their bikes through. I appreciate the help, maybe I will get one of each, haha.

[nickjpass]

So if you'd be racing MX, what would you use? Sorry for thread jacking..

[DMC707]

So if you'd be racing MX, what would you use? Sorry for thread jacking..

Would depend on my budget - but ideally i would want a 4 stroke -- but i personally wouldnt buy a used 4 stroke unless i knew the previous owner (thankfully for me, i have a pretty deep pool to draw from there if i ever want a used 450)

---- the last time i bought a bike, budget was not a concern to me so i bought a new 450, had the suspension re-valved and re-sprung, new titanium/carbon exhaust, rekluse clutch, and a few other bits and pieces of "bling" that vet riders like to throw at their bikes when they love them --- bike cost over 10k when the dust settled , but with my customization for my needs, its the finest piece of machinery i have ever rode with a few nit-picky exceptions --- i've had it 4 years now and likely will keep it another year due to the bath i am going to take when it is time to sell it

If i was on a more serious budget --- i'd think long and hard (thats what she said ? ) about a 2 stroke. I have a clean 99 YZ250 in my garage already, so that would be free -- add in $500 to re-do the top end and crank bearings (mine doesnt need it yet - but a lot of older 2 strokes do ) - $500 to perform the same suspension mods i did to my 4 stroke, then $400 for the Rekluse plate system clutch, plus 200 for new tires and another 300-500 for incidentals (plastics, drivetrain, etc) - and my old bike is race ready for another season or 2 for 2k ----- and if you dont have a donor bike gathering dust in the corner of your garage like i do, then add another 2k (or possibly less ) for a donor 2 stroke to give the treatment to.

I love my 4 stroke, but the 250 2 stroke makes competitive power in the class i ride in and definitely cost less to get your foot in the door

[nickjpass]

So, since I'm a high schooler who works at McD's, do you think I should stick with my original plan of getting a 2006+ YZ125? I can't afford a $7000 four stroke, and don't want a used one blowing on me..then I'd have to rebuild it which would be the equivalent of a decent 125 lol

[DMC707]

So, since I'm a high schooler who works at McD's, do you think I should stick with my original plan of getting a 2006+ YZ125? I can't afford a $7000 four stroke, and don't want a used one blowing on me..then I'd have to rebuild it which would be the equivalent of a decent 125 lol

That plan actually sounds pretty good ---- keep in mind the 250-F's have been faster since day one on an MX track, but on the other hand , most MX tracks are not top end oriented, --- but a bike with a lot of torque may gap you a bit out of corners

--------- The YZ's are cool, plus if you are high school age, your track may have a few schoolboy or 2 stroke only classes you can ride in ---- and the 125 should be competitive through the C class easilly even AGAINST 250-f'S ---- C class sounds pretty meager, but keep in mind that C class motocross is still pretty dang fast

I hate to pull a "back in my day" quote --- but 20 years ago when there were 125, 250 and 500 classes locally and there were 30 A class riders on the gate at any given weekend , and the B and C class was so deep they had to run heats almost, ---- poor boys used the same 125 to run all 3 classes (i was one) --- the bike was never the factor in who won or lost unless the bike broke -- even 125's against 500's ---- sure you would never get a holeshot against anyone running a big bike, but fitness and talent used to mean something too, (and i'm pretty sure it still does )

----- i will add that i'm 41 years old now and would probably never go back to a 2 stroke personally, because the power characteristics of a 4 stroke match the way i like to ride now , --- but i can go just as fast on my 250 2 stroke admittedly. A lot of people say they love 2 strokes because they are more "fun" --- i am the opposite, i love my thumper -- i can think about things like line selection and other things rather than messing around with a bunch of clutch and shift work -------- the 2 stroke is more of a pain in the ass , but its definitely cheaper

Edited October 31, 2012 by DMC707

[G.P.]

A lot of people say they love 2 strokes because they are more "fun" --- i am the opposite, i love my thumper -- i can think about things like line selection and other things rather than messing around with a bunch of clutch and shift work -------- the 2 stroke is more of a pain in the ass , but its definitely cheaper

I was 100% with you until I rode a KTM 250 XCW this year. The spread of power and low end torque blew me away. After years of riding Japanese MX 250's I had no idea that a 2 stroke could feel so much like the 4 stokes that I know and love. My 250 will drag me up nasty hills barely above idle without stalling just like my old 4 strokes. I can only imagine that a 300 would be even better.

The only down side now for me is the vibration.

[nickjpass]

Thanks for all the information, really helped.