Anyone have a long term opinion on running a big bore with taller gearing for highway? I know the KLX isn't a touring machine but I use it like one. I want to be able to cruise 70 a little easier and I'm just thinking up ideas on a Monday night...

I love my KLX and it does everything I need very well but I need to connect 2ish hours of highway to get anywhere decent and I don't always want to trailer my junk...any thoughts? I don't mind the KLX on the highway but I need a little advantage when it comes to crazy California drivers riding my *** all the time.

 

Hmmm...having not been to California, I can't say exactly what would be better. Having a bigger bore will provide more power which will come in handy if you need to move really quick, but it won't have much more speed. Changing the sprockets is a 50/50 choice. You gain something, but you give up something else. If you're going to be mainly highway, then you can either up the front sprocket, or lower the rear. Should you do both, big bore and gear change, do some research on mpg of the bore kits as well as power curve, and I would start with the lowering the rear sprocket a couple teeth first.

 

True, the 250 is actually really happy around 62-67 mph. Actually, 60 is perfect as far as power and almost no vibes. 65-70 seems to have the most vibes and the bike is kind of maxed out depending on the situation. Yeah, I've had my bike up to about 85 or so but if I'm cruising highway 1 or 280 with a slight up hill and a head wind then good luck. You're stuck just going back and fourth between 5th and 6th just to hover around 65. Most people tail gate like crazy and go 10-15 mph over the speed limit. Hell, half the time if I'm going 5-8 mph over I won't even slow down if a CHP gets on the highway and cruises next to me. With that being said I was thinking if a BB could push lower gearing just as easy as stock but around the 70 mph mark. That way I have a little reserve and hopefully the bike will cruise 70 like it does 60-62. I guess this is peanuts when most bikes cruise 80 no problem, lol.

Usually if I slap on my 13t sprocket and knobies I'll trailer my junk because I'll be doing some bashing and if I break my junk I want to be able to still go home. If I do highway gearing I'll probably only be doing fire road and two track at most. Mainly because I'll be alone and I'm the only crazy *** hole out of all my friends that does over 300 miles a day on my 250.

 

I understand completely. I start getting pretty bad wobbles around 70 and over, but had it up to 88-90 the other day. If people tailgate like crazy, I'd definitely want the extra power that a bore kit can provide. However if you're going to stay 250 for a while, I'd probably go up a tooth in front and down a couple in the rear just to have that much more highway advantage. You'll be able to achieve a higher speed at lower rpms, but you'll also be giving up low end torque. Since you seem to do lots of highway commuting, that's the way I would go. If you're going to an event or something where you plan on doing some other kind of riding, just throw extra sprockets and chain in the little pouch or take a bag with you. Swap it out when you get there, then swap again before you leave. It's more work, but it could be worth it. Also if you're going to be going that fast, I would highly recommend a steering stabilizer.

I don't have a big bore kit myself, yet, but I have been doing lots of research on them. The two most popular I have found is Bill Blue's 351 kit, and he also offers a pumper carb, and then you have Kustom Krafts 331 kit. Aside from the extra 20cc difference, the 351 kit barely cuts into the coolant flow, so he puts a steel sleeve in the cylinder, whereas the 331 is Nikasil plated.

P.S. Bill Blue offers more than the 351 bore. Home Page

 

I'm leaning towards a 331 my self but I'll probably stick with the stock CV carb, although I'd like some mild web cams. I'd like to get a bigger bike but I'm totally torn on what I'd get right now. Part of me wants a cheap cash deal like a used 650 Dakar, but thats a ten year old bike although they are great non the less, or I like that new Versys 650 or a newer Sertao or F800GS. I'm also waiting to see how the new Honda Africa Twin pans out...but I really don't want payments again though...



In all honesty the KLX is killing it, especially when I'm out minding my own business, I just friggn love this little bike. I'll probably wait another year or so until I get a bigger bike that can really eat up highway.

 

I have another option for you.. You can get a significant power increase in the entire upper end -6-10k - with an FMF header and matching carb setup.. Add a 15 tooth and you have your highway cruiser..


My bike powers thru 90mph with the 14..

 

I don't know if it's true in all cases but I know the amount of vibration between my KLX351 and my KLX250 was quite noticable at higher rpms. Neither were geared for street though, both being 14/47, but the 250 seemed happy buzzing along at 70 mph, while the 351 seemed forced when pushed to that speed.

Lower gearing might minimize this effect.

 

The KLX is a lousy bike for a 2 hour highway slog. Sell it and buy something more appropriate. If you gear the KLX to handle that with ease you'll have poor woods gearing.

If you run real knobbies for the woods you'll wear them down on such a long paved ride.

You really can't have a single track capable bike that runs well on extended highway rides. You're going to give up something somewhere. You really want a KLR or a DR650, which is made for this type of compromise.

I see it a lot that people get into false economies with their bikes, trying to make a tourer out of a supersport, or an super sport out of a standard, or a commuter out of a 2-stroke. They reason that they already own it, but having cash is a craigslist ad away.

The KLX can be a lot of things, but it can mostly be better at what it is, which is a fun trail bike. It'll never be a KTM and it will never be a good highway bike.

 

+1 How about a trailer or hitch rack?

 

I guess I could always try a 15t with my good ol 250...or maybe bump the rear down a pinch. Really I'm just looking for a 300-500 rpm dip and that should put where at the speed I want with minimal vibes. I just don't want to be totally bogged out worse than it is in certain conditions. I've got a new cheap-o eBay header that I was going to try but the inside of the "bomb" is less than stellar. I'll try and post some pics I took with a borescope, its not crappy but I'm less than thrilled...but what would you expect from a purchase like that.


I know its no highway cruiser but going through the country, windy roads and any where else, even if there is no dirt, this bike just rocks. I do have a trailer but its friggn annoying loading, finding parking and so on. On the plus side taking the roads less traveled is awesome when they're around.