Leaning out my KDX

[91KDX]

I talked with Jeff Fredette and told him I was tired of fouling plugs in the woods with my 98 KDX 200 and he told me to lean the bike out. I was already running 50:1 premix, and when I went to email him back I haven't gotten a reply and that only happens when he is out of town racing. What I want to know is how should I lean my bike out? I run 50:1, have a a FMF Rev Pipe, Air Box Mod, I am not sure what the previous owner is running for Reeds though. I don't have a manual for this bike so I don't know if the carburators are the same as a 91 KDX 200. Is there an Air screw that I should turn or should I change jets? I need all the help I can get here. Thanks
Ben

 

[procircuit21]

50:1 is actually richer than say 32:1 or 40:1, i didnt know that until just recently. When you talk about fuel mixture ratios, if you have one ''unit'' of fuel that has 1 part of oil and 50 parts of gas, then it would be richer than 32:1 for example because 50 parts fuel is more than 32 parts fuel per one ''unit'', if that is understandable. Reading the carb tuning guide on the main site will expain it better. So, I would try running 32:1 or somewhere around there first and see if that fixes your problem. Also, make sure your air filter is clean, because if it isn't, it will allow less air to get in while the same amount of fuel is being delivered, richening the mix. If all that doesnt work, just try dropping a size or 2 on your jets. Yet another reason to read the carb tuning guide under tech tips on the main site it is very helpful.

 

[cfr1970]

When refering to "Leaning" a bike out, it isn't refering to gas oil ratios. It's refering to the air fuel mixture. When going to change your jetting, there are a ton of posts on this site that will give you a reference starting point depending on mods and altitude.

 

[CaptainObvious]

If you like 50:1, leave it there. When Jeff advised to to lean the bike out, he was refering to the jetting. You'll need to take a look at what your current jets are as a starting point. There are many great posts (many recent) about jetting.

Inventory your current jets and get your bike in a clean running state (plug, air filter, powervalve, packing & pipe). Check your reeds to make sure they are within limits as well. From there you can start to adjust the jetting.

 

[89kdx200rdr]

next time u talk to him tell him where u live and ask him to recommend a starting point. or look on the kdxposed section of his website. for a little help tho im at 1600 ft elev running amsoil series 2000 oil with exxon 93 at 50:1, 45 pilot 1173n in 3rd position, 155 main. as soon as i get it im going to a 152 main. oh airscrew runs best at 1.25 out but this may be diff for you. if you dont have any jets mr. fredette's site is a good place to get them plus alot of other stuff.

 

[91KDX]

Ah, Jeff knows where I live, and everything I just want to know where to start. I am taking my bike apart and going through every thing this week so I will let you all know. By the way, does anybody know where Jeff has been? I haven't heard from him for like a month.

 

[89kdx200rdr]

last time i emailed him with a question he said he had been outta town. back as of 6/4 didnt ask where he was.