I just received a KDX200 snorkle. Dynojet reccomends the 124 main with the snorkle removed, but the KDX200 snorkle must provide some restriction, so I'm thinking the 120 may be right. Suggestions apprecated.
The bike is a 09 KLX250s with stock exhost and air filter. Sea level.
Craig

 

Yes, with everything else being stock, a 120 main will be just fine. If you ever plan to step up to an exhaust and a hi flow air filter, a 124 would be better.

Let me ask you a question though, you have the snorkel and you obviously have a jet kit. Why not also get a high flow air filter and an exhaust?

To me these are must haves for any KLX. It is a completely different and better bike with those mods.

 

Excellent question. The DJ kit specifies the 116 with OEM airbox.

I'll tell you what I would do. Put in the bigger snorkle and test ride it, look to see if the main is too lean.

It is a lot of work to swap the main jet out.

On the air filter... the OEM air filter is freaking huge and looks to be quite capable of all the air needed for this bike. I have heard that it is the same filter the KX500 uses. I am not convinced that an aftermarket foam filter will be any better. Send me your OEM filter, I'll take a marker and write "hi-flow" on it and send it back to you if you would like.

 

I don't know, I stuck my K&N on mine and you could tell a difference. I can't speak for foam filters but it made mine run better.

 

The stock foam filter is denser than the hi-flow aftermarket foam filters. Maybe the stocker does flow enough, but the aftermarket filters have the possibility of flowing more.
Dan

 

With the 116 it ran awful. The 120 was better but still surging. The 124 made it a new bike. Much better aceleration, and running with no surging at any throttle position.
Money is the reason I am not doing the exhost. Maybe next year.
So far I have spent $58 on the Dynojet kit and $16 on the snorkle.
When it comes to bang for the buck, opening up the intake trumps an aftermarket muffler and header.
I have found I can change the main jet by removing the screw holding the throttle cable bracket, lossen the carb boot clamps and twist the carb so the bowl faces the right side of the bike. No need to remove the tank, seat or hoses.
Craig

 

Wow, good to know. I would have thought for sure it would run fine on a 120.

I had a header, muffler, jet kit, snorkel and kandn and i had a 124 before the big bore and my bike ran fantastic.

 

Great news about being able to swap mains without all of the disassembly. I would have thought that the exhaust would be in the way of dropping the bowl to the right.

Also pretty interesting that just the snorkel swap had such a huge effect on jetting. Maybe the OEM exhaust isn't that bad. I'm like you, if the exhaust was cheap I would have it on there. Crash damage really saps my bike budget.

 

The mains are change-abe while still on the bike, exactly how you did it. One tip that helps make this easier, is to change the bowl screws over to allen head screws. This allows you to get at the fasteners with a shorter tool. Allen wrench vs phillips screwdriver. It also helps prevent stripped heads , like when the phillips screwdriver slips and cams out. Just be careful of over tightening with the added leverage of the allen wrench.
Dan

 

I run the DJ 124 with the KDX 200 snorkle installed. No problems with the engine running. If you run the KLX with the KDX snorkle and a better pipe, then I would suggest using the 128 jet.