Ok, my son has an O4 LTA-50 which is a great bike for him (just turned 4, been riding since 3). I have read just about every post on this forum about mods to this little machine and came to my own conclusions and have done some mods that I have not heard of yet and I want to share them because they worked extremely well. The obvious mods we all know about which are removing the restrictors and rejetting the little machine. STOP right there! I decided after running a "dial-a-jet" on my Rancher and knowing how well this works I would try and install one on the LTA-50. Problem is they don't make one for this little thing. I called Thunder Products and asked them to send me the smallest one they had.

Here it goes: Ok, if you don't know anything about a dail-a-jet, get to the web site (thunderproducts.com) and read about it (awesome product). After recieving the dial-a-jet I went to work removing the carb and air box, drilled out the airbox cover with as many large and small holes that I could to open the thing up without actually removing the cover completely. I had already done some research and had in my possession a K&N pre-charger model RU-0210PK. I cut the 3"round by 5" long charger down to 3" round x 2.5" long (this means cutting off the elastic band end). This will become the airbox/precharger for the airbox cover with a hose clamp to hold it on the cover after it is installed (prechargers have a one way microfiber that keeps out water, dust, dirt, clay, oil and other debris). Next I removed the body of the airbox from the carb (2 screws). The body of the airbox is where the dial-a-jet will be installed. I drilled a small hole in the mounting spot of my choice and mounted the dial-a-jet body with injector, installed it, marked the injector for modifications (it needs to be cut because it is too long for the 50's little carb bell. The end of the injector should set center in the carb bell). After marking the brass injector I removed it and placed it in a vice. Using a dremel tool I cut about a 1/4" off the incector, reinstalled and whala! One custom dial-a-jet body with injector. Now comes the float bowl drain screw mod. Dail-a-jets come with a float bowl drain screw replacement that allows the gas in the bowl to actually be routed up to the dial-a-jet body via a small tube so the gas can be emulsified into a fine mist. This fitting is much too long for the little 50's bowl so once again you must cut this brass fitting about 1/2 way up the threads, remove the float bowl drain screw and replace it with the newly modified fitting. Last but not least I used a 67.5 main jet, needle at 2nd from bottom and no other changes to the carb. This particuler jetting would be considered very lean for an LTA-50 with no restrictors in and an open air box but the dial-a-jet needs a lean condition to actually work it's magic (once again, read about the concept on thunder products web site). Last but not least I removed the oil injections system from the quad, dropped in a one step cooler spark plug and premixed the gas at 35:1 ratio. (2.56oz of oil per .7gal tank) #of gal. x 128 / ratio = oz. of oil needed per gal for said ratio. After finding the correct dial for the dial-a-jet (2nd richest dial) I place the thunder products snorkel kit on the dial-a-jet body and presto! Done!

Results: This little quad gets up and goes! It actuall sound clean and crisp throughout the rpm range like a 2 stroke should. My son can now turn the quad full turn, stab the throttle in soft dirt and it's donut time. Roost in the sand and no more getting stuck on the mildest grades. Much more responsive from 1/4 throttle to wide open. No more jetting changes for altitude or heat, just twist a dial and it's done. Perfect jetting for any situation every time, all the time. The smile on my sons face and the terror in my wifes eyes is the true story here. [img]i/expressions/face-icon-small-blush.gif[/img])

No it's not going to go out and beat a 90cc quad, nor is it going to be the fastest 50 on the planet but it's now a fun little machine and will be very competative (with a pipe) if my son ever decides to race the little thing.

I posted this after realizing how much these little machines rely on jetting and how finiky they can be with altitude or temp changes. With this set up I will nevery have to touch the jetting again and the bike will alway run at optimum capacity in any weather/temp/altitude, all with the turn of a dial. If you need to see pictures of the carb/dial-a-jet mods let me know at: joe@washingtonadventurequads.com and i will try and e-mail you some pics.

If I can only convince Thunder Products to start making an actual LTA-50 dial-a-jet kit now!???

Current mods: Dial-a-jet (custom) dial set at 2nd richest setting at 500ft altitude.
Drilled air box with K&N pre-filter
removed oil injection with gas mix of 35:1
One step cooler plug
removed intake and exhaust restrictors
ground steering stops for better/sharper turning (donuts)
67.5 main jet
needle at 2nd from bottom clip

One happy Dad and son:

 

Here is a great article on the Dial-a-jet from the editor of atvconnection.

https://atvconnection.com/editor/gen...ialjetting.htm