how hard is it to maintane modern MX 4 strokes

hey guys iv just been wondering how hard it is to maintane those thumpers, iv been considering maybe trying to get one
 
Not that bad. It's more than a 2 stroke but still not terriable.

oil change every 8 hours, new filter too.
I clean my air filter every other ride.
Check the vlaves 2 or 3 times a season (50$ for a mechanic to do it)
bleed the air out of the forks every ride (on 2 strokes to with bleeder valves)
keep chain tight, clean and oiled.
keep you tire PSI good

Basically just oil changes, valves checks and air filters. Then all the regular stuff to keep it running well. I'de like to see you on a 4 stroke.
 
Not that bad. It's more than a 2 stroke but still not terriable.

oil change every 8 hours, new filter too.
I clean my air filter every other ride.
Check the vlaves 2 or 3 times a season (50$ for a mechanic to do it)
bleed the air out of the forks every ride (on 2 strokes to with bleeder valves)
keep chain tight, clean and oiled.
keep you tire PSI good

Basically just oil changes, valves checks and air filters. Then all the regular stuff to keep it running well. I'de like to see you on a 4 stroke.
i do all my own work, i know how to work on them just iv heard they go though top ends like crazy. but if all it needs is what you said you may see me on a 4 stroke sometime in the future. i would like to take a spin on a 250f to see how different they are from 2 strokes.another thing about 4 strokes is they cost alot i would have to save my nickels and dimes for awhile to get one.
 
Yeah I know what you mean. Anyhow 4t race bike have incredible low down torque, and all over really. You will feel very safe with the power because it havs exactly what you need, wherever, whenever and however. It's a myth they go through top ends like that. They last 2 times longer than a 2 stroke. 2 stroke + 2 times longer, 2+2= 4stroke.

If you need help with that stuff, get racing on your 85, then get some sponsers after you get your 250, then money won't be so tight compromising your bike.
 
Yeah I know what you mean. Anyhow 4t race bike have incredible low down torque, and all over really. You will feel very safe with the power because it havs exactly what you need, wherever, whenever and however. It's a myth they go through top ends like that. They last 2 times longer than a 2 stroke. 2 stroke + 2 times longer, 2+2= 4stroke.

If you need help with that stuff, get racing on your 85, then get some sponsers after you get your 250, then money won't be so tight compromising your bike.
i thought it would be but wasent gonna spend that much money on a bike if i had to work on it forever and put alot of money intoit, :lol: if you talk me into gettin a 4 stroke you'll be my dads new best freind (he's a 4 stroke guy)
 
then I better make sure as shit I do! But anyhow, 4 stroke race bikes are really good. I mean, I'de reccomend one to anyone who wants to go fast and get serious.
 
then I better make sure as shit I do! But anyhow, 4 stroke race bikes are really good. I mean, I'de reccomend one to anyone who wants to go fast and get serious.
yeah, what would you recamend most kx-f crf-r rmz or yz-f? iv heard yz-f has 5 valves which is realy nice
 
The Maintanence isn't so bad as the cost of maintaining.... unless of course you trail ride then you can forego alot because of the mild use (When compared to MX) I do 2 topends a season on my RM, my buddy does 2 topends on his CRF450, plus new valves... I can't remember if he does valves 2 time or just once. I think just once for total valve replacement. after 2 years he had to do a total rebuild on his bike to a tune of about 1500, just in parts. He did the labor himself. I think he adjusts the valves every 10 hrs.
Now My buddies kid races a KX250F. The 1st year he was ok, just valve adj. the second year 2 total rebuilds. and a fresh motor every season from then on. He rides 2-3 times a week adjust valves every week cuts the head 2 times a season and replaces the valves alot. He's also extremely fast and IMO should be running a 2T the way he rides... Always on the revlimiter...
The 4ts are reliable but if you aren't willing to clean your filters after every ride, check the valves every week, and follow a strict maintenance regiment then they can be costly.
 
yeah, what would you recamend most kx-f crf-r rmz or yz-f? iv heard yz-f has 5 valves which is realy nice
KX250F or YZ250F. Yamaha and Kawasaki have been the best bikes I have ever owned. I'de go Yamaha because of the 5 valve and suspension. Plus it has RAW power, same as the kawasaki. The kawis a good all around bike, yamaha has awesome suspension, great valves, super lightweight and monsterouly good power. Just my choice because I have one and I love it to death. :ride:
 
I know a kid, he is 14, big into mx through out Washington Oregon an Cali. He races 250f B class, and is very fast. He has a stock and mod bike, usually the current year for each season(right now 2011 kxf). His dad puts about $6000 to build the mod bike alone... insane...

For the casual rider like yourself i would plan on at least $550 every 125 hours of trail for engine work alone, that should give you a top end including valves and cam chain,,,,

good luck to yah, now you see why my bike smokes...
 

James

Staff member
The important thing with 4t's is cleaning the air filter and I mean religiously. Other then that change your oil as often as possible, I change mine at least every 5 hours. That and check your valve clearances every 20-30 hrs, you shouldn't have to adjust them until 100 or more hours though. Not sure why Mihylo's buddy is adjusting his every 10 hrs, either he's getting dirt into the engine or he has other serious problems. :noidea: After you adjust them the first time they seem to fade pretty fast to.

You also have to remember that just because one guy is going through 2 top ends a year doesn't mean you will. A ProAm or A rider who's always on the rev limiter will go through A LOT more parts then the more casual riders, plus their bikes are usually modded to kingdom come. Which takes away from reliability. For example, a local guy was telling me about how his kids 250f was so heavily modified that the engine would only last a little more then one race. But that monster could practically take a stock 450f.:shocked: Also the amount of hours they actually ride will probably be different then you, due to them practicing every day. Practice 5 days per week plus races, compared to the casual riders who can only ride 1-2 days a week.



Basically:

  • Clean your air filter often
  • Change your oil at regular intervals (Get a cheap hour meter to better track your time)
  • Remember that you have massive torque on the bottom and there's no need to rev the piss out of them.
  • Clean your air filter
  • And just in case you haven't caught on yet, Clean your air filter. :P
 
The important thing with 4t's is cleaning the air filter and I mean religiously. Other then that change your oil as often as possible, I change mine at least every 5 hours. That and check your valve clearances every 20-30 hrs, you shouldn't have to adjust them until 100 or more hours though. Not sure why Mihylo's buddy is adjusting his every 10 hrs, either he's getting dirt into the engine or he has other serious problems. :noidea: After you adjust them the first time they seem to fade pretty fast to.

You also have to remember that just because one guy is going through 2 top ends a year doesn't mean you will. A ProAm or A rider who's always on the rev limiter will go through A LOT more parts then the more casual riders, plus their bikes are usually modded to kingdom come. Which takes away from reliability. For example, a local guy was telling me about how his kids 250f was so heavily modified that the engine would only last a little more then one race. But that monster could practically take a stock 450f.:shocked: Also the amount of hours they actually ride will probably be different then you, due to them practicing every day. Practice 5 days per week plus races, compared to the casual riders who can only ride 1-2 days a week.



Basically:

  • Clean your air filter often
  • Change your oil at regular intervals (Get a cheap hour meter to better track your time)
  • Remember that you have massive torque on the bottom and there's no need to rev the piss out of them.
  • Clean your air filter
  • And just in case you haven't caught on yet, Clean your air filter. :P


The 450 guy is a vetC/B rider... pretty fast but rides alot..
The 250F kid is wicked fast and should be riding a/semipro but fails to focus. That kid hammers his bike, holy smoke. Thats the bike I raced SX with.... wish I had my 2T for that race :cry:
lol
 
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