Woohoo, I made contact with Chris from Miniquadracing today. The spring kit includes 3 different "levels" of springs, although he mentioned that the stiffest set along with machined shoes works best. Along with the 62.5 main, I'll post results when the parts arrive.

 

Great news. We'll be waiting.

 

Just wondering where to find the K&N air filter for the Lt 50, my local dealers have no clue.

 

Ru-0200. You will have to order through your dealers or K&N.

 

Well, my 5 year old placed 3rd place at Glen Helen yesterday in the 50cc class on the LTA-50. I have to say, the 50 corners well and handles the whoops faily well but the other quads ate it up out of the hole and on the straights! Those LEM and other asian 50's have a slew of aftermarket parts for them. I don't know whether to keep moding the LT or move on. In the current state of tune it's twice as fast as stock, just doesn't have the power. 60cc big bore kit??? Clutch and gearing mods???

 

Dump it.

Here are a couple strikes against the LT vs the Kasea's, Lem's, etc:
-Piston port vs. reed valve. Reed valves make power over a much broader range.
-CVT transmission (not on LEM's). Gives you both acceleration and top speed. While it's certainly possible to make serious performace with just a centrifigual clutch tranny (see the KTM/Cobra/LEM 50cc dirtbikes for example), a motor making good power and very high revs are needed.
-Availability of chassis components. From a-arms to shocks, disk brakes to axles, it's all available for other mini quads, not the LT as of yet.
-Ease of maintenance. While I haven't wrenched on the other mini's, the LT sucks with it's enclosed foot area, and small size. If you're racin', you're wrenchin'.

I think the LTA50 is probably the best rank beginner quad out there for kids in the 3-5 year old range. Lightweight, passable suspension, sufficient power (with restrictors removed), front and rear brakes, and most of all- small size, including the all-important inseam length. As the child's size and riding ability increases, you are fighting a loosing battle.

 

Still waiting to hear how the clutch springs and 62.5 jet worked out.
Also much difference did milling the head down do.


Thanks

 

The clutch springs didn't work too well, and I'm less than excited about the service I received from MQ Racing.

It took a week of me leaving messages before I got a call back, and the initial e-mail was never repiled to. When I did talk to Chris (the owner), he was polite, helpful, and said the springs were a kit of 3 different pairs of springs, but that even the stiffest pair was too soft. It would, however, be a real improvement over stock.

When I received the springs/jet, one of the springs was wrong (too long), there were no instructions, and I was charged $15 for S/H. Heck, it all would have fit into a padded envelope. Concerned, I left a few messages over the next week for Chris, who never called back.

I pulled a pair of calipers out to figure out which should be the stiffest, and slapped the thickest pair of springs in. The clutch would engage just before max rpms, and would only pull my butt around on a downhill. Way too stiff. Next pair down, not as bad, but still terrible. After cutting and bending the incorrect length spring to the correct length, I put in the softest pair. Better, than stock? Kinda. On a slight downhill these springs would allow enough slip to get it to accelerate pretty well, but the stock ones still climbed hills better.

I am not convinced the softest pair is a lost cause. I bet that if you looked at the LT's power curve on a dyno, it would climb right off of idle, and then stay flat until peak rpm's. A clutch needs to engage when the engine is climbing in power, not being flat. I'm guessing that a good pipe would work well with these springs. The other issue I'm having is a bog that appears about a second or two after nailing the throttle from low rpms. This happens to be at about the same rpms at which the softest springs engage. I seem to have this issue regardless of what jetting I run. I've tried raising the float level a bit, but to no avail. More testing is needed, but I'm quite frustrated with the lil Zuk.

I'm thinking the clutch springs that I received are the same ones used in some of the CVT clutches, but I don't really know. Here are some measurements:

Stock wire diameter: .064, length from inside of hooks: 1.085
Red diameter: .082
Blue diameter: .084
Black diameter: .086
Length of aftermarket springs from inside of hooks: .950-.954 (except for the one wrong red one).
Length of aftermarket after being run for about 5 minutes: 1.005- 1.019

 

I know this is a old topic, but i just recently bought an LT-50 for my son. All restrictors are off, and it still needs a little more. Wasnt wanting to spend all the money on it right now. Has anyone messed with changing the sprockets? We're looking for more low-end power, top-end power is fine for now.

 

dave@ilrperformance has 18mm mikuni carbs and filters to bolt onto the LT-A50 and the KXF-50. It uses regular mikuni jets and is a big top end improvement.
He also has the pipes for the quads for 40.00 less. The pipes are made by Power Pros and Graydon puts their name on it.
They also have clutch kits, big bores and do all of the machine work.
After trying to make it run well, I gave up and took it to Dave. Now mine runs circles around what it used too and on the flat track it will run with the Italian quads (finaly!!!!)