450F Maintenance?????

[CLAYTO]

How much regular/expensive maintenance is required for 450F's?
And why do they all seem to not always start easily?
On a small maintenance budget,am i way better off buying a 250 2stroke?
Im wanting 2 upsize from my 125 and want the low down b4 i buy.
Cheers!
CLAYTO

[hughes]

What type of riding do you do? If you are going to ride a 450F the way it was designed to be riden (W.O.T) then you could have more expensive maintenace items. Just like any other engine things need to be checked for proper adjustments and wear. Keeping up on your valve adjustments, changing the engine oil/fitler every other ride, clean air fitlers every ride, these items will help ensure max life from a four stroke. Yes, parts cost more for the four stroke engine to be rebuilt and it can get real expensive if you have major failure. IMO any dirt bike requires alot of maintenance. I think it's heat related to why they are so hard to restart after they get hot. These four strokes are running hotter temps than the 2-strokes. Fuel and heat don't mix.  I have never owned a four stroke dirt bike but each year I think about it more and more about buying one.

[alan]

4 strokes lots more moving parts = More expensive!

[KXcam22]

Clayton,
  The new 4-strokes have reached an unbelievable level of performance.  A fast 450 comes close the the stock KX500.  However, they have made some sacrifices to get that performance.  The tuning level of most 450's is close to that of an indy car. Very highly stressed, very high RPMs.  Trail riding a 450 will make it last much longer, but when comparing a years-proven 2-stroke 250 to a 4-stroke 450, I can almost guarantee that the 250 will take less maintenance, and the maintenance will be cheaper.  For a rider on a budget I suggest that the 250 is the way to go.  Pick a high quality 2-stroke oil, clean your filter lots and it will last far longer than you expect. The 450 will be much faster but the 250 will give you more fun/$$.   Hope this helps. Cam.

ps. My apologies in advance to the 450 crowd.  I personally would get myself the 450 since I have the resource$$ and mechanical abilities to keep it flying.

[don46]

It really depends on the type of riding your going to be doing, if you plan on racing MX then by all means go 4t otherwise you'll get eatan alive, if its trail riding go 2t. As all the post state there are many more moving parts in a 4t, I've had 3 250f's, mainly because you can't compete on a 125, My son prefers the 250 2t and as such we decided to not get a 450 last year, however this year we did get the 450 to level the playing field. I haven't had 1 bit of trouble with my 4t, I change oil/filter frequently as well as the air filter after every ride, pistons are changed about every 1-2 months and I install the heavier valve springs right from the git go. I do the same maintenance on the 2t also.  I'm on the extreme end of maintenance, you would be somewhere in the middle, most people don't change pistons but once a year, change oil, adjust valves  and enjoy, the 4 t are a blast to ride.

[hughes]

It really depends on the type of riding your going to be doing, if you plan on racing MX then by all means go 4t otherwise you'll get eatan alive, if its trail riding go 2t. As all the post state there are many more moving parts in a 4t, I've had 3 250f's, mainly because you can't compete on a 125, My son prefers the 250 2t and as such we decided to not get a 450 last year, however this year we did get the 450 to level the playing field. I haven't had 1 bit of trouble with my 4t, I change oil/filter frequently as well as the air filter after every ride, pistons are changed about every 1-2 months and I install the heavier valve springs right from the git go. I do the same maintenance on the 2t also.  I'm on the extreme end of maintenance, you would be somewhere in the middle, most people don't change pistons but once a year, change oil, adjust valves  and enjoy, the 4 t are a blast to ride.

How often are you replacing valves,cutting valve seats,valve guides,cam chains, etc.?? Or you have not needed to perfrom these repairs at this point.

[don46]

I haven't had to do any of these, but I only keep a bike for a year. Even the bikes I've sold are still around and have not had to have the valves ground. The key is to install the heavier valve springs, this eliminates float and damage to the seats, the other element to long valve train life is a clean air filter, if any debris gets past the filter intake valves fail prematurely.

[CLAYTO]

Thanks heaps everyone!
Sounds like 250 2stroke is definitely the go 4 my budget.
Thanx for ur help
CLAYTO

[hughes]

I haven't had to do any of these, but I only keep a bike for a year. Even the bikes I've sold are still around and have not had to have the valves ground. The key is to install the heavier valve springs, this eliminates float and damage to the seats, the other element to long valve train life is a clean air filter, if any debris gets past the filter intake valves fail prematurely.

Any carbon build up on the valve stems or faces??

[don46]

nope