Jet kit for 1987 Honda 250X

[VT250X]

I need to jet my 250x and I was wondering what kit I should purchase? I have an WB E-series exhaust and headpipe as well as a UNI air filter and air box holes. The stock main jet size is a 125. Would the 120 - 130 kit be the one I should get or the 130 - 140? I want a variety to tune with, but I don't want to have to buy two kits if I don't have to. The motor itself is stock.

Thanks,

LM

[bwamos]

I'd jsut buy individuals and get 5 increments.
Since you have a 125 in there.. get the 130. THen you can either fine tune up to a 132 or down to a 128.

I highly doubt you'd make it up to a 135. My 330ex (with the stock carb) runs between a 138 and a 142

I'd imagine you'll end up with a 128 (lid on) or 130 (lid off). If your really low elevation (below 300ft) you may bump those 2 sizes up to 130 and 132 due to more oxygen in the atmosphere.

[300exOH]

Originally posted by bwamos
I'd jsut buy individuals and get 5 increments.
Since you have a 125 in there.. get the 130. THen you can either fine tune up to a 132 or down to a 128.

I highly doubt you'd make it up to a 135. My 330ex (with the stock carb) runs between a 138 and a 142

I'd imagine you'll end up with a 128 (lid on) or 130 (lid off). If your really low elevation (below 300ft) you may bump those 2 sizes up to 130 and 132 due to more oxygen in the atmosphere.

It's possible that you'll need a 135. I have a sparks full system and stock motor w/no lid and a UNI and I'm running a 135 main. I am at about 300-500ft. above sea level. You may want to pick up a 40 and 42 pilot jet also. This will help with cold startup and any hesitation off idle. I agree about buying the individual jets though. It's much cheaper than a kit.

[bwamos]

Aye it's definatly possible every engine is different. The sparks X-4 is a straight through very unrestrictive design though (it's what I use, too). His WB E-Series will have diverter plates on it (most likley) and the 250x doesn't have the added stroke of the 300, so he'll be a little leaner on the main jets.

I doubt he'll need a new pilot. But good advice if his air screw won't do the trick. I still have the stock pilot jet in my 330. No hesitation. I am running a slightly richer needle though.

When he said kit.. I beleive he's refering to the "package" of jets you can buy from Keihin that has a 120-122-125-128-130 mains in it. I think they are like $18. Not the dynojet "kit".

I'm definatly not the "expert" on jetting. So don't take my observations as gospel. ;) I cheat, I have an Air/Fuel monitor for our ATV's, lol. ;)

I also may not have given enough of a bump up for removing the lid after installing the new pipe and filter.

[300exOH]

Originally posted by bwamos
Aye it's definatly possible every engine is different. The sparks X-4 is a straight through very unrestrictive design though (it's what I use, too). His WB E-Series will have diverter plates on it (most likley), so he'll be a little leaner on the main jets.

I doubt he'll need a new pilot. But good advice if his air screw won't do the trick. I still have the stock pilot jet in my 330. No hesitation. I am running a slightly richer needle though.

When he said kit.. I beleive he's refering to the "package" of jets you can buy from Keihin that has a 120-122-125-128-130 mains in it. I think they are like $18. Not the dynojet "kit".

My sparks also has the diverter plates/spark arrestor. I noticed a slight hesitation with the stock pilot from idle to about 1/8th throttle which is why I'm running a 42 pilot. You are right though that every engine/conditions are different. I am using the stock needle. I didn't realize you could buy packaged sets of keihin jets. I just bought mine individually. I would deifinately stay away from the dynojet kits. I have heard many folks have trouble getting things dialed in with them.

[300exOH]

I'm definatly not the "expert" on jetting. So don't take my observations as gospel. ;) I cheat, I have an Air/Fuel monitor for our ATV's, lol. ;)

I also may not have given enough of a bump up for removing the lid after installing the new pipe and filter. [/B][/QUOTE]

Can you give more info on the air/fuel monitor? I'm not 100% sure my jetting is dead on but it seems to run very well. I'm definately no jetting expert either but I do have some experience.

[bwamos]

Originally posted by 300exOH
My sparks also has the diverter plates/spark arrestor.

Ahh.. I have the turndown style on my 330. I decided to cut 2" off of it, so the turndown would clear the grab bar. I was too worried about setting it up on its hindquarters. Besides it's MUCH easier to clean when you can put it on its haunches.. lol. Was very easy to do. The stainless steel core was a little harder to get the pipe expander to work on though. Turned out very well, and looks factory.

When I first got my 300 in '98 I used the dynojet kit with a FMF PowerMax pipe, and K&N filter. It worked perfect. Of course pipes then were much simpler.. no fancy stuff, like powerbombs, reverse megaphone, tapered headers, etc.. WB e-series didn't even exist yet.. lol.

Sorry a little off topic. ;)

Back to the topic..

I'd but a 130 and 135 form the dealership. Then when you find the one that's closest.. take the other one back and exchange it for the next size you want to tune too. ;) Most dealerships will exchange them without question as often as you want. They just toss them back into the bin.

[VT250X]

Thanks for all of the great advice. I was refering to the Keihin jet kits not the Dynojet kits (my bad). They probably sell those kits in tons of places, but I also need a few nuts and bolts and it's easier to deal with www.bikebandit.com and they carry the keihin jet kits as well. I think there like $21 for a set of 5 I think.

At any rate the reason I wanted the kit is I wasn't sure if i was going to do any engine mods over the winter (cam, piston etc.) so I wanted to have some larger ones . Most information I have read with a similar setup as mine were using a 130. Maybe I will get a 128, 130 and a 132 and work my way from there. I should probably get a new pilot as well just in case although nothing I've read has stated that the pilot needed to be changed.

As far as the "plug test" goes let me just verify the steps. I run my wheeler under full load, full throttle in top gear for 15 seconds. Then I hold in the clutch, keep the throttle pinned and hit the kill switch and come to a rolling stop. I remove the spark plug and check the condition from there. Is that correct or am I missing a step?

Thanks again for all of your help.

LM

[wilkin250r]

It's probably reasonable to say that you'll never go DOWN on jets, so you don't need anything below your 125. If I were you, I'd pick up the 130-140 jet kit, and then pick up an individual 128, and you'll have the whole range for whatever you want to do in the future.

[VT250X]

Originally posted by wilkin250r
It's probably reasonable to say that you'll never go DOWN on jets, so you don't need anything below your 125. If I were you, I'd pick up the 130-140 jet kit, and then pick up an individual 128, and you'll have the whole range for whatever you want to do in the future.

That's what I was planning on doing. It wouldn't hurt to have extras.

LM

[300exOH]

Originally posted by bwamos
Ahh.. I have the turndown style on my 330. I decided to cut 2" off of it, so the turndown would clear the grab bar. I was too worried about setting it up on its hindquarters. Besides it's MUCH easier to clean when you can put it on its haunches.. lol. Was very easy to do. The stainless steel core was a little harder to get the pipe expander to work on though. Turned out very well, and looks factory.


Yea. I have noticed that the turndown style is longer than the spark arrested version. Mine only comes out about as far as the rear plastic. Sorry to get off topic. lol

VT250X- I'm pretty sure the procedure you explained for the plug test is about right. I think 4th gear will work fine though. You may not need to change the pilot but you never know. Mine was so lean at idle and it was very hard to start if the temps were below 70 degrees. the 42 pilot made it so I don't even need the choke unless it is really cold out. Good luck with it.

[bwamos]

Originally posted by 300exOH VT250X- I'm pretty sure the procedure you explained for the plug test is about right. I think 4th gear will work fine though.

Agree. His procedure was perfect. 4th gear would be fine so you don't have to have such a long distance.

[VT250X]

Originally posted by bwamos
Agree. His procedure was perfect. 4th gear would be fine so you don't have to have such a long distance.


Great. I have a bit of a long distance, but some of it is up a small hill. Still it should run better than it is now.

Thanks again.

LM

[Blue250X]

i hate to but in but what do all the jets look like and where on the carb are they located for a 250X. i know where the pilot is , but where are the others and pics are appreciated. thanks

[300exOH]

Originally posted by Blue250X
i hate to but in but what do all the jets look like and where on the carb are they located for a 250X. i know where the pilot is , but where are the others and pics are appreciated. thanks

http://www.atvriders.com/articles/pilotjet.html

http://www.atvriders.com/articles/jetting.html

Check out these two posts in the articles section. Should help ya. The main jet is right next to the pilot.