New to 4 stroke.

[Kev250]

Hi, tried a search but got nothing back of any use.

I have a 97 KX250 and an '04' one. Both great bikes and I'll be keeping the '04'.

I'm going to add a 4-stroke to my collection, my question is whats the best to go for, a KXF250 or 450? I'll be wanting something no older than 3 years. I'm an average rider, hobby only, I go to tracks, hilly quarrys and really I'm just starting to do jumps and things now. I'm used to the power of the 2 stroke and I no longer find it violent or uncontrollable, which makes me think about going for a 450. Just wondered what you guys think. Anyone got any advice. There's a KTM test day near me soon so I'll be having a go of their 4 strokes to try out the two power levels. Thanks.

[lilyamaharacer9]

Hi, tried a search but got nothing back of any use.

I have a 97 KX250 and an '04' one. Both great bikes and I'll be keeping the '04'.

I'm going to add a 4-stroke to my collection, my question is whats the best to go for, a KXF250 or 450? I'll be wanting something no older than 3 years. I'm an average rider, hobby only, I go to tracks, hilly quarrys and really I'm just starting to do jumps and things now. I'm used to the power of the 2 stroke and I no longer find it violent or uncontrollable, which makes me think about going for a 450. Just wondered what you guys think. Anyone got any advice. There's a KTM test day near me soon so I'll be having a go of their 4 strokes to try out the two power levels. Thanks.

Your best bet would be to try one of each, then go with which ever you like more, but remember the power delivery and how long it pulls is different from brand to brand.

[the white stallion]

Things to cosinder.

Your weight,You have a 250 2 stroke with lots of power, a 250F might feel a little low on power if you weigh more than 170-180 and ring the crap out of your 250 and are a mad man.Bike weight-I think your 250 is kinda light compaired to a 450F but the 450 is gonna have more than enough power(more than you want?) with some added weight.The thing about a 450f is you always have xtra power and aren't ringing the bike out might prolong valve life as opposed to having a 250F on the limiter all the time.

I suggest like someone mentioned above try to get to ride both bikes from freinds or someway.

[Kev250]

Thanks for the reply's.

I weigh 170lbs.

This is what I've been thinking. I'm not the hardest rider but I'm not exactly shy with the throttle either. My 250's are well and truly tamed and I'm using all the bike. I have a mate who has loads of bikes, RMs, KX's And a YZ250F, he says that knowing the way I ride and what I use it for he thinks I might get bored with the 250F and I'll wish I had got a 450F fairly quickly. However, about a year ago I had a go of a CRF250 and I thought it was a torquey animal, felt really nice, but I couldn't ride as well back then and the 2 stroke 250 felt like way too much bike then too. I'll just have to have a go of some and see whats what. Trouble is, I'd ideally like to buy one nearly or brand new, so for that reason I had better figure out what I want first, I don't want to end up buying too much or too little bike if you know what I mean.

Anyone else recently made the jump from 2 to 4?

[Pr1malR8gw]

heres a thing to consider. I have a blast on my 250 and have consider several times stepping up to a 450. How ever I feel the bike will take to much to realy have fun with. I've since decided to just up the bore ony my bike instead of getting a 450. a big bored 250f will have more power with out the addition of weight. It will also be less of a bear to keep fully in control.

[amnesia622]

I ride and race a 06 CRF450 and 09kx250f. If I could only have one I'd keep the 250f. The power on the new one is unreal. I had a 06 kx250f before. I'm 175lbs and would go with the 250f. its way more forgiving and its more fun to actually rev it out. I always have more fun on the 250f. I have YET to complain about the power too. On the track the 250f anyday even at Southwick. If you are in open pits most of the time the 450 doesnt feel as much as a beast.

[Kev250]

Thought I would update on my decision making. The 97kx is sold so I have a spare slot in the workshop, 04kx is staying as I love it for hill climbs and jumps in the old coalmine/quarry I sometimes go to. The new four stroke - I think its going to be an 08 or 09 kxf250 I go for. I know it'll feel a bit slower than my kx but this is my local track and this is where it will be used most -

http://www.scottishmotocross.co.uk/tracks/coupar-angus.htm

In truth I see this as a 250f track, I'm never in anything higher than 3rd gear on my kx and I get very sore arms after 10-15mins on the bike here, much more than when riding anywhere else. If it turns out I was wrong I can always upgrade to a 450, or get both! I considered a KTM but I think I'll stick to my Kawi addiction for now.

[Kev250]

Right. I've been in my local shop today, and I have narrowed it down. Don't want an RMZ, wouldn't entertain a Honda after the valve horror stories I keep getting told so:-

Basicly I'm choosing between a KXF 250 or a KTM 250 (SXF? can't remember the mx model name).

I have a choice between brand new 08's or 09's and I'm not sure what to go for, the money difference is negligble really so I was thinking 09. There is also a nice used 08kxf in there for £3000 (4800 USD) which is tempting, and the guy also had a few low hour 07's there but I don't know if I want one that old. Has anyone got any info/advice/opinions on the kxf's? i.e is there anything to look out for between the models? The KTM's do look nice and I know they are supposed to be better, but deep down I think it will be a Kawasaki for me again. My 04 kx250 feels so nice compared to my mates CR's and RM's, its silly but I can't seem to see past the green. I've also heard about hot start valves on 4strokes, are they essential or do they just make life easier? Could someone explain exactly what the valve does? I'm going to my track tomorrow with a guy from work who has a new CRF450, its going to be hard to resist but I don't want to have a shot, I think it will spoil my first shot on my new 4st 250. Thanks for any replies.

[amnesia622]

It wont spoil it. Depends on what track you are on. New crf doesnt feel as "revolutionary" as they make it out to be. Its nice then you ride the new 09kx450f and say "Wow why isnt this bike getting more attention!"

The valves control when the fuel can enter and exhaust can exit the cylinder .

[D-K]

I belive he was talkng about the hot start circuit when saying "hot start valve"...

If you were, then it´s a little lever on the handlebars that you pull to get the engine to start easier after a fall or stall when the engine is hot.

4-strokes like some fresh lean air to start when the are hot...

Just som lube on the plunger every once in a while will keep it working good...

[Mulciber]

Yeah, the hot start just gives the engine a gulp of fresh (cold) air.

You won't be dissapointed by the power a 250f puts out. It sounds like you'll be safely out of the '04 range but don't touch one... They were a time bomb. Essentially '04 - '08 the engine stayed the same save for subtle re-workings (except the '04 which I believe is the same platform but they toughened them up a lot), but the top end parts are completely interchangeable (correct me if I'm wrong on bottom end?). I'm not sure on exact details but the frame went alum. from '06 on and the suspension got overhauled a couple times.

The guy I ride with all the time rides an '08 YZ450f and it's a monster -seriously- If you're into point and shoot climbing and that kind of thing they'll take you to the top while you grab a gear on the way up... But I can keep him on just about everything his climbs with my KX250f, it just takes a bit of extra work, which honestly I like... It provides a challenge all the time, you've really got to think about what you're doing and push it there. When it comes to trails, open or tight, neither one of us can run away from the other. And after coming from 250 two strokes it hasn't left me dissapointed at all... And I love the torque every time I twist the throttle down low, it just doens't seem to get old

Even after riding his 450 once in awhile I still love getting back on mine, I doubt you'll feel any worse for riding one (especially just cause of the way a Kawi fits, hehe).

Good luck man.

[Kev250]

I belive he was talkng about the hot start circuit when saying "hot start valve"...

If you were...

Yeah thats what I was meaning! I know what engine valves are! ha. It is funny how many people ride bikes without any mechanical comprehension though, so I can see the confusion. I've got a mate who probably couldn't change his brake pads, but he can ride with the best of them!

Thanks for the info guys. I had a feeling the hot start valve would just be a cold air intake of some mechanical operation, are they standard equipment on new bikes? I'm probably going overboard with the 250 or 450 debate but I really don't want to buy a new 250 and "want" for more power so thats why I'm being carefull to make the best choice. I've heard the 09 kxf250's are stunning to ride compared to older models, and I've read that a few times now too which speaks for itself.

[Mulciber]

The hotstart is standard on the works I believe. It's actually just a part of the carb. Almost every four stroke on the market now (maybe all I'm not 100%) uses the Keihin FCR carbs (or FCR-MX) including the 4T quads. Which is really nice when you're doing any kind of work on them, so many people have good info on jetting etc. and parts are plentiful.

I know how you're feeling with the debate though... I wish I could just go buy an '09 KX250F, but I just can't spring that kind of cash I love the power mine has but it feels like it could use just that little bit so I decided to go with a 290cc Athena big bore and a set of Hot Cams (stage 1) this winter and see just what I get out of that... If it doesn't cut it maybe I'll just move toward a 450F instead I like the idea of retaining the weight and handling of my 250 though... And a lot of people have had nothing but good to say about the same setup... Guess I'll find out.

Anyways, good luck and let us know how it all goes down man.

[Kev250]

Anyways, good luck and let us know how it all goes down man.

Hey guys, ended up getting an 08 RMZ-250, sorry! The plan is to keep my 04kx250 and the RMZ for another 6 months then trade in both bikes for a kxf-450. Saying that, if I end up loving the RMZ and 250 power I'll likely keep it, its a sweet bike so far and unfortunately I have to say that it handles better than my kx so I'm well happy. Came to the decision after riding 4st 450's and 250's at my local track and as its a tight track to ride I was more comfortable on the 250.

[D-K]

I´m not surprized that you thought the RMZ handled better that that 2-stroke KX. The old KX´s were never really good handlers, and the Suzukis have always been known for their sharp handling...

However, there are lots of small little things that I don´t like on suzukis, the seat bolts for example, are too small and tend to strip the threads.

The c-clip that holds the cams sideways are located in the head instead of in the cam caps.... Strange and harder to mount.

The radiator wings stick way out past the seats edges, and make it "anti-sleek" in lack for a better word.

The suspension is wimpier than most, and the powerband is a bit short.

Some people might disagree, but these are my opinions.

Hehe, don´t mean to bag on your new bike, the Kawis ain´t perfect either!

I hope that you have lots of fun on it, and that you are happy with your decision!?

[Kev250]

However, there are lots of small little things that I don´t like on suzukis, the seat bolts for example, are too small and tend to strip the threads.

The c-clip that holds the cams sideways are located in the head instead of in the cam caps.... Strange and harder to mount.

The radiator wings stick way out past the seats edges, and make it "anti-sleek" in lack for a better word.

The suspension is wimpier than most, and the powerband is a bit short.

Some people might disagree, but these are my opinions.

I'm not too worried about any of those points, if thats all that's bad about them then I'm laughing:) I'll be back to Kawasaki soon for a 450 anyhow.

In answer to the above. Seat bolt threads seem ok to me, and its no big deal to repair if they do strip. C-clips is no big deal either, if they're hard to insert then you know they'll stay in. Suspension seems fine to me so far, in-fact I'm convinced its lighter than my kx, and as for the powerband - 3 people have told me that kxf's and rmz's have the same engine and they are have the best power delivery out of the 250's.

Only worry I have is false neutrals, I heard the 07's were bad for it but 08's are ok. We will see, last thing I want in the back of my mind when I'm at the rider skill point of just starting to hit doubles and back slopes of tabletops.

If I get the first sign of trouble I'll get rid of it.

[D-K]

The engines were only the same in -04 and -05. Since -06 they have redesigned them on their own and been going in different directions. I´m not saying that either one is better, it´s a preference thing.

Good luck with the bike!