Chico, eh?
You know an old dude named Ray, forgot what he rides.
KLR now maybe.

 

I pulled my stock piston out at about 100 hours. I did it only to raise the compression. The piston looks perfect, there is nothing wrong with it. If you only saw the sides, you would think it was brand new. The cylinder didn't have a ridge or a mark, either.

 

The old 250r and other 2- strokes can't be compared to the new 4-strokes on rebiulding. You can rebiuld a 2-stroke for around $100. The 450's will cost about $1500 when they goes bad. You can get buy for less, but the total rebuild in in that range. You should hear some of the m/c riders that have switched from 125's to the 250F complaining about the rebuilds.
If you take care of the 450; cleaning the airfilter, oil, and don't run it hard hard it will last. But, when it needs a rebuild it will cost you.

 

I did a search on 450r longevity and found this thread. It appears to be pretty old and Id like to bring it back now that alot of you have some significant time on your 450s.

I will be buying a new 400ex, Z400, or the 450r in the near future. Im wondering about the experience you guys have had with your 450r engines. We ride A LOT. I live in an area that you are free to ride at will (no hauling bike to designated spot) and I will be doing mostly trail riding (central PA). I do like to have alot of power on tap. This is my main reason for considering the 450

I have been riding since I was 7 years old and I know how to maintain and repair the machines we ride so im not one to skip oil and filter changes and stuff like that.

That being said. What kind of longevity are you guys getting from your 450s? My decision has come down to this question and I cant for life of me seem to get a straight answer.

 

We've got TRX450R's out that have never been re-built and are driven a lot .. They only look similar to the CRF450 which does need to be re-built especially if raced ..

 

<div class="FTQUOTE"><begin quote>Originally posted by: Roostin79

I did a search on 450r longevity and found this thread. It appears to be pretty old and Id like to bring it back now that alot of you have some significant time on your 450s.



I will be buying a new 400ex, Z400, or the 450r in the near future. Im wondering about the experience you guys have had with your 450r engines. We ride A LOT. I live in an area that you are free to ride at will (no hauling bike to designated spot) and I will be doing mostly trail riding (central PA). I do like to have alot of power on tap. This is my main reason for considering the 450



I have been riding since I was 7 years old and I know how to maintain and repair the machines we ride so im not one to skip oil and filter changes and stuff like that.



That being said. What kind of longevity are you guys getting from your 450s? My decision has come down to this question and I cant for life of me seem to get a straight answer.</end quote></div>

First off, if you mostly ride trails, the 450 is not the best choice! These engines like to rev, so I perfer them for wide open country. On a tight trail, you will need to do a lot of annoying clutch slipping....but these engines will hold up for hundreds of hours even with the HRC kit!

If you ride fast more open trails, then the Z is the ticket. It is considerably faster than the EX, the frame and handling are excellent, and the engine will hold up just fine. Gets fuel injection this year, if you are buying new!

The EX is the choice for slow very technical trails. Its engine will lug down, and I can ride through technical idling in 1st gear. Again, excellent frame and handling, and this engine will last forever with just basic maintenence.

One note, all the 450's with their little slipper pistons tolerate a lot of compression blow-by. That means the oil get rapidly contaminated with fuel mixture....so you need to do frequent oil changes! Doesn't hurt to check the valve clearance frequently either.

 

If your buying a TRX get an 05. They are more reliable that the newer models. Much better tranny also....

 

<div class="FTQUOTE"><begin quote>Originally posted by: Off-Road Master

If your buying a TRX get an 05. They are more reliable that the newer models. Much better tranny also....</end quote></div>

U mean the 400 or 450? I assum you meant the 450 since im pretty sure the 400 in unchanged

 

I've had mine since Feb. '04 and although I did go to an Athena 480 a year later I have still have had no problems with it.
I went with the 480 not because it needed a rebuild but because I wanted the added power. The original cylinder and piston still looked new after a years worth of riding.
Those who thought that the 450R would need rebuilds every 100 hours have been proven wrong.
Change the oils frequently, keep the air filter clean and keep the valves adjusted and it is a very reliable engine.