4 stroke knowledge help

If not abused a 4 stroke will require much less major maintenance. When it does it does cost more for the parts.
If you stay off the rev limiter you will have a good running, long lasting 4 stroke. If you bounce it off the rev limiter regularly, it just will not last. Remember that these 4 stroke engines are built for high RPM's and high horsepower at almost any cost and thus the life is just a lot shorter than that of a street bike 4 stroke engine.

Paw Paw

Going with what paw paw said, even if you do rev the thing pretty good, they can still have a pretty good life expectancy so long as you keep up with the maintenance. I hammer on my bikes pretty hard, but I change my oil, oil filter, and air filter religiously, check my valves fairly often, replace a piston, rings, and cam chain every 30 hours, and crank every 60 or so, I’ve gone quite a long time without a catastrophic failure. It’s not cheap, but I’d rather spend a few hundred bucks a season on that than grenade a motor. I do my own work though, so if you have to factor in labor, that jacks the price up significantly.

Paw Paw 271 wrote:

If not abused a 4 stroke will require much less major maintenance. When it does it does cost more for the parts.
If you stay off the rev limiter you will have a good running, long lasting 4 stroke. If you bounce it off the rev limiter regularly, it just will not last. Remember that these 4 stroke engines are built for high RPM's and high horsepower at almost any cost and thus the life is just a lot shorter than that of a street bike 4 stroke engine.

Paw Paw

not sure ill be bouncing it off the rev limiter as i cant really do that with my 125, but i feel like the 125 cant throw me up a jump as the power isnt there immediately, im like 14 stone so its not like im light and it struggles for jumps straight after sharp corners. Would you recommend a 4 banger for motocross over a 2 stroke?

murph783 wrote:

Going with what paw paw said, even if you do rev the thing pretty good, they can still have a pretty good life expectancy so long as you keep up with the maintenance. I hammer on my bikes pretty hard, but I change my oil, oil filter, and air filter religiously, check my valves fairly often, replace a piston, rings, and cam chain every 30 hours, and crank every 60 or so, I’ve gone quite a long time without a catastrophic failure. It’s not cheap, but I’d rather spend a few hundred bucks a season on that than grenade a motor. I do my own work though, so if you have to factor in labor, that jacks the price up significantly.

Yeah taking a 4 stroke motor apart is not quite the same as a 2 stroke, a lot more to it! most likely be done a shop i would imagine.

If you can mechanically handle working on a 2 stroke you can do a 4 stroke. It takes me about twice as long but I'm very meticulous and there is more to it. I was always a 2 stroke guy but these new 4 strokes are bada$$ and I love the power delivery. I would suggest riding a 250f and even a 350f and see what you like best. Also try a 250 2 stroke, it's the only way to really decide.

ktm-5 wrote:

If you can mechanically handle working on a 2 stroke you can do a 4 stroke. It takes me about twice as long but I'm very meticulous and there is more to it. I was always a 2 stroke guy but these new 4 strokes are bada$$ and I love the power delivery. I would suggest riding a 250f and even a 350f and see what you like best. Also try a 250 2 stroke, it's the only way to really decide.

I’d agree with that. It’s all just nuts and bolts, nothing too crazy. A service manual and some patience goes a good long way.

ktm-5 wrote:

If you can mechanically handle working on a 2 stroke you can do a 4 stroke. It takes me about twice as long but I'm very meticulous and there is more to it. I was always a 2 stroke guy but these new 4 strokes are bada$$ and I love the power delivery. I would suggest riding a 250f and even a 350f and see what you like best. Also try a 250 2 stroke, it's the only way to really decide.

Only thing putting me off a 250 2 stroke is the little error for mistake in terms of throttle control, and I don't want to move to a ktm as I'm in love with the cornering on my yz and my friends ktm seems to lack that tight rear wheel turning. Perhaps a big bore kit, too many options hahah!!!

When you average the cost over time its cheaper with 4 strokes. They dont require that much maintenance. Keep the fluids and filters fresh and youre good. When its time for a top end, mostly youre doing a piston and cam chain and thats not much more than a 2 stroke. Additional cost is basically the $50 cam chain. Valves and all that last a long time and dont need redone every time you do a top end. They arent horror machines like most 2 stroke fanatics make them seem to be. Thats for sure.

kb228 wrote:

When you average the cost over time its cheaper with 4 strokes. They dont require that much maintenance. Keep the fluids and filters fresh and youre good. When its time for a top end, mostly youre doing a piston and cam chain and thats not much more than a 2 stroke. Additional cost is basically the $50 cam chain. Valves and all that last a long time and dont need redone every time you do a top end. They arent horror machines like most 2 stroke fanatics make them seem to be. Thats for sure.

Fair enough fella, I think I'll run a year out on my 2 banger, and swap it up come winter. I have 2014 yz125 with few extras, what 4 stroke would you point me in the direction of? I've heard some people slate hondas for engine issues. Yzf 2016 250 looks pretty good, seems to be a lot of them about too. Any preferences?

kb228 wrote:

When you average the cost over time its cheaper with 4 strokes. They dont require that much maintenance. Keep the fluids and filters fresh and youre good. When its time for a top end, mostly youre doing a piston and cam chain and thats not much more than a 2 stroke. Additional cost is basically the $50 cam chain. Valves and all that last a long time and dont need redone every time you do a top end. They arent horror machines like most 2 stroke fanatics make them seem to be. Thats for sure.

ChrissyDMX wrote:

Fair enough fella, I think I'll run a year out on my 2 banger, and swap it up come winter. I have 2014 yz125 with few extras, what 4 stroke would you point me in the direction of? I've heard some people slate hondas for engine issues. Yzf 2016 250 looks pretty good, seems to be a lot of them about too. Any preferences?

Im a kawi guy. Cost, reliability, and bike stability are all appealing to me. Pick a color honestly.

Keep the 125 and learn to rip it. It takes skill to ride a 125 fast and yes it will get you over most jumps... learn to rev the 125... my old 125 got me over all the jumps that it needed too and I’m 200lbs ( sorry I’m to lazy to google and convert to stones ) 2 stroke are cheaper to rebuild as well, if your smarter than a monkey and I assume you are you can rebuild the 125 motor from top to bottom in a weekend

Start with something Good don't buy somebody else's poorly maintained bike.