Long term KLX250S review

[cjbiker]

Originally Posted by alpiner84

Good morning everyone,

My friends helped me lower my KLX last night, so now I can ride the thing! The Kuoba lowering links (#4's) lowered the bike a full two inches Doesn't feel like the same bike, but I least I can stop at stoplights without fear of falling over.

Unfortunately, I can't really ride it still because the darn thing won't start most of the time. It only starts if it's above 60 degrees, which never happens on Colorado mornings, so it's a day-time only bike right now. I understand I'll have to re-jet the carb, but there's so much info on that and other mods that what I'd like from you folks is a condensed sort of cliffs-notes version of what I need to do. Simple one-line answers are fine, I really just want someone to tell me what to do

1) What kind of re-jetting will I need to do at this elevation? I'm at ~6000 ft, and ride up into the mountains. Do I need to change out the pilot and the main jets, or just one or the other? What about the needle?

2) I've seen talk of the Kuoba T-handle A/F mixture screw--should I be getting one of those, too?

3) What's this business about "drilling out" the carb? Do I need to do that, too?

4) Should I do anything to the airbox? I've seen many options, mostly combinations of remove the lid and/or remove the snorkel and/or replace the snorkel with the KDX. Which of these is easy and effective?


and, other stuff....

4) I'm going to replace the bars so I don't have to mess around with the ends of the bars to install hand-guards. I'd like to stick to the stock dimensions so I don't have to mess around with cable lengths. Are the Pro-Taper SE 7/8" CR High Bend bars (mentioned previously) my best bet?

5) I need a new brake lever and new mirrors--any rec's? I don't really need anything too fancy, I just can't sift through all the options out there.

I'm going to get the Acerbis tank, the B&B skid plate, HT's pannier frames, and....thank god, I think that's it!

Any answers to the above questions will be greatly appreciated! In the meantime, I'm going to continue reading this nifty pdf about how carburetors work.

1. I would think the factory jetting is pretty close at your altitude. It's a little lean at sea-level and needs the idle mixture richened up (which requires removing the carb and drilling out a plug). The DynoJet kit made for our bikes has a new spring and needle, which are great. They include a range of main jets, and a guide that suggests which to use. I would call them up and find out which main jet they recommend for your altitude, since the setting recommended in the paperwork that comes with the kit seem to be on the rich side. The starter jet in this carb is not removable. See # 3.

2. The Kouba screw allows you to adjust the idle mixture without tools. Nice, but not required.

3. The starter jet is pressed in. Many think it's too small to allow good cold starts. Drill it out to 0.018" with a #77 drill bit. You can get a pack of 10 bits on ebay for under $10.

4. As far as I'm concerned, the jury is still out on the airbox mods. I've got my jetting dialed in very well with the stock airbox snorkel, and it runs great. I thought it was a gas hog with the KDX snorkel and the Dynojet-recommended jetting for a modified airbox, and I did not notice any improvement in power. Your mileage may vary, as they say.

4 (b). I have Renthal Jimmy Button bars on my bike. I like them, and they just barely fit with the stock cables.

5. OEM brake lever is $3 from Ron Ayers. Can't beat that. I have an EMGO folding mirror. It stinks. When I have $50 that I don't know what to spend on, I'm going to get one of Neduro's "Double Take" mirrors. Top shelf stuff there...

In my opinion, the first thing you add should be handguards. They are a bear to fit to these bikes because of all the crap on the bars and the way the brake line is routed, but well worth it. They protect your hands when you are riding in the woods, and protect the controls when you drop the bike. Money well spent!

[alpiner84]

Excellent info, thanks!

Originally Posted by cjbiker

1. I would think the factory jetting is pretty close at your altitude. It's a little lean at sea-level and needs the idle mixture richened up (which requires removing the carb and drilling out a plug). The DynoJet kit made for our bikes has a new spring and needle, which are great. They include a range of main jets, and a guide that suggests which to use. I would call them up and find out which main jet they recommend for your altitude, since the setting recommended in the paperwork that comes with the kit seem to be on the rich side. The pilot jet in this carb is not removable. See # 3.

3. The pilot jet is pressed in. Many think it's too small to allow good cold starts. Drill it out to 0.018" with a #77 drill bit. You can get a pack of 10 bits on ebay for under $10.

So to fix the not-starting issue my bike has, should I try just drilling out the pilot jet? Or, since I have the carb out to do that, should I get/install the DynoJet kit, too? I suppose what I should really do first is pull the spark plug and see what color it is...but (this is embarrassing) the plug on my last bike was very straight forward to remove, just a spark plug socket on a normal socket wrench. This one seems to be in there at a weird angle, like I won't be able to get to it with the regular tools I have. Does that sound true?

[Ranger Ron]

Originally Posted by alpiner84

Excellent info, thanks!



So to fix the not-starting issue my bike has, should I try just drilling out the pilot jet? Or, since I have the carb out to do that, should I get/install the DynoJet kit, too? I suppose what I should really do first is pull the spark plug and see what color it is...but (this is embarrassing) the plug on my last bike was very straight forward to remove, just a spark plug socket on a normal socket wrench. This one seems to be in there at a weird angle, like I won't be able to get to it with the regular tools I have. Does that sound true?

You don't want to drill the pilot jet. The pilot jet is replaceable (screws in). The jet that is drilled for cold starting is the "cold start jet". It is pressed in. At your elevation, I would suspect you won't need to drill it.

Most likely the oem pilot jet will work just fine for you. However, you will almost certainly need to remove the anti-tamper cap and adjust the idle mixture screw. 1 1/2 turns out works well for most. Adjusting this will probably cure your cold start problems.

Be sure to leave the throttle closed when starting with the "choke" on.

Don't waste your time trying to get a plug reading. With modern gas, the plug will always look too lean unless you are jetted ridiculously rich.

Ron

[total_n00b]

Originally Posted by cjbiker

In my opinion, the first thing you add should be handguards. They are a bear to fit to these bikes because of all the crap on the bars and the way the brake line is routed, but well worth it. They protect your hands when you are riding in the woods, and protect the controls when you drop the bike. Money well spent!

FWIW I had pretty good luck fitting the TrackSide handguards on my KLX, on ProTaper bars. They fit well, were fairly easy to install, and have been down a few times - so far, they've held up well. I originally purchased a set of Acerbis guards, but couldn't get them to fit, so I went w/TrackSide.

[alpiner84]

From CJBiker:
The pilot jet is pressed in. Many think it's too small to allow good cold starts. Drill it out to 0.018" with a #77 drill bit. You can get a pack of 10 bits on ebay for under $10.

Originally Posted by Ranger Ron

You don't want to drill the pilot jet. The pilot jet is replaceable (screws in). The jet that is drilled for cold starting is the "cold start jet". It is pressed in. At your elevation, I would suspect you won't need to drill it.

...consensus?

Most likely the oem pilot jet will work just fine for you. However, you will almost certainly need to remove the anti-tamper cap and adjust the idle mixture screw. 1 1/2 turns out works well for most. Adjusting this will probably cure your cold start problems.

Now I'm confused again: I thought the idle mixture screw was that handy-dandy black knob near the choke, the one that changes the idle when I turn it

FWIW I had pretty good luck fitting the TrackSide handguards on my KLX, on ProTaper bars. They fit well, were fairly easy to install, and have been down a few times - so far, they've held up well. I originally purchased a set of Acerbis guards, but couldn't get them to fit, so I went w/TrackSide.

Thanks! Make my shopping list that much simpler!

[Ranger Ron]

Originally Posted by alpiner84

Now I'm confused again: I thought the idle mixture screw was that handy-dandy black knob near the choke, the one that changes the idle when I turn it

That's the idle speed control, not the mixture control.

Ron

[mel brooks]

Originally Posted by alpiner84

...consensus?

Ron is correct. The STARTER jet is pressed in. PILOT jet screws in.

I think CJBiker was confused with that post.

[IDRIDR]

Adjusting the pilot screw may help with starting.
I'll respectfully disagree with RangerRon though and suggest drilling the enrichment/choke/cold start pressed in jet to 0.018" while you're in there if you're having cold start issues. It made a huge difference for my '06 from 2500 ft up to 8000 ft. Also, beware of the ebay bits because others have found significant inconsistencies in their sizes. I picked up 2 bits for $2 at my local Hobby Town. Be very careful doing this that you drill with a hand drill (not power). Some guys used their exacto knife handle. I picked up a hand drill for small bits. You will be taking off just a very small amount of material, making this jet just a tiny bit larger.

[cjbiker]

Yes, Ron's correct, it's the starter jet. The one you can't remove.

I'll go back and modify my post so no one finds it through a search and drills the wrong jet.

[alpiner84]

Okay, so here's the new plan:

1) Order and install the Acerbis gas tank, the Pro-Taper bars, the Track Side hand guards, the OEM brake lever, new mirrors, and a KLX 250SR kickstand (forgot to mention that one).

2) Order the Kuoba A/F mixture screw (seems like it will be nice to have)

3) Remove the carb:
-- remove the tamper cap on the fuel mixture screw, adjust it 1 1/2 turns
-- drill out the cold start jet to 0.018" very carefully not with a power drill
-- swap out the fuel mixture screw for the Kuoba one

4) Replace carb and adjust using the mixture screw and the idle speed control

5) Start my bike in normal morning temperatures and ride

Am I missing anything? I mean, except the knowledge and experience that will make this easy

Also, on a completely different note, is it easy to reroute the choke? Because I hate where it is on this bike.

[Ranger Ron]

Originally Posted by alpiner84

Also, on a completely different note, is it easy to reroute the choke? Because I hate where it is on this bike.

If you hate it now, you will really hate it after you have the Acerbis tank installed.

Here's what I did:



It has a flexible shaft like a speedo cable.

Your plan sounds good. You don't need to wait for the Kouba screw. You can put that in later.

Ron

[IDRIDR]

Ranger Ron did it right with the choke lever. Nice job Ron!

I just dremmeled about 1/3 the side off my stock knob handle to make it like a "D" and it works. He's right...the acerbis tank makes it worse to grab. I'm used to it. I first put my acerbis petcock wth the handle pointing toward the front of the bike....wrong. point it back. my petcock is not easy to turn.

Use a sharpie and mark 0 turns on a line on your Kouba screw against the carb body above the screw. That will give you an alignment point. Thank Dan888 for that point.

Enjoy!

[redpillar]

If you remove the stock petcock all together you can slide your fingers in there and find the choke pretty easy, but you have to make your own hose connector from the acerbis tank. I like the Ranger Ron fix as well.

[vamtnman]

Try this before tearing into the carb:

I have a 2009 and have never had a cold start problem. A previous poster had reminded me of an old dirt bike trick I used to use with my KDX200;

Turn on the fuel, pull out the choke, put he bike in gear and rock it back and fourth four or five times.Take it out of gear and fire it up.

I've used that procedure since I bought the bike about five weeks ago and have never had it fail. Of course I'm at around 1800 ft and the temp. has always been at least 40 f.

On hot starts, the owners manual says closed throttle but I've found that a little throttle is required or it doesn't want to start.

[djchan]

Looks like I'll be adding a 2007 KLX250S to the stable in a week or so.

I've seen the power mods (351, pipe/silencer, etc) but have a couple other questions.

First, on the weight - I'd like to lose some weight off the stock bike. I know an aftermarket exhaust will lose 5 pounds or so. How about trading the stock headlight/display unit for a simple dirtbike headlight with a trailtech endurance display. Seems that between the units and the loss of the bracket system there should be another 5 pounds at least.

How are the superlight weight batteries (shorai, turntech, etc) Don't know how big and heavy the stock battery is. Is there a few pounds there as well?

Rear light unit? Any savings there?

Has anyone gone on a KLX250 weight reduction plan? Is it even worth it all in all. Experience?