CraptainChaos

I looked at it under a microscope once it dried out.... and it seems that the 'wad' was a mixture of various small/fine hair-like fibers and a whole lot of dust. I can only guess that as the carb had not been serviced since I got the ATV .... and probably not for a long time before (maybe never since new in '95), and that in a previous life the quad was a farm vehicle. That the fibers may have been a mixture of fine animal hair and hey / grass, and that the dust /fiber wad had gradually built up over a very long period of time. Anyhow, I used it yesterday pulling a harrow for a couple of hours and it behaved very well - started well and had plenty of torque. So it seems that the carb service & most likely the removal of fuel restriction cured it. Cheers J

Hi, I think I just found out why my LT-4WDX was starting well and loosing power / faltering when it got warm.... It seems to have not been when the engine warmed up, but after a period of time! Let me explain; Having checked the fuel pump and valve clearnces I decided to buy a service kit and give carb a complete ovelhaul. When I removed the fuel needle valve housing I discovered a wad of fine fibre type crud backed up against the mesh which covers the bottom end of the valve housing. It seems that while this wasnt causing a complete block, it was restricting the fuel flow to the bowl. And when the engine was demanding more fuel there was enough surplus in the valve for a short while, but after 5-10 minutes of work the restiction in the fuel supply meant that the carb could not deliver enough fuel in the mixture for more than about 10 min hard use at a time..... but on tick over it would run and run! Anyway, carb has now had a good clean and been treated to new jets..... and crud removed. Tomorrow the quad is going to get some serious use, so fingers crossed. Hope this helps someone out there. Cheers J

Hi Hunterchub. Did you get to the bottom of this? I thought I had a breaktrough last weekend - I was checking the vacuum and breather pipes to the carb, and noticed that the fuel pump vacuum pipe was a little loose at the carb end. So trimmed it back to improve the fit in case it was leaking. The quad started great after that, and ran better than it had for a long time. However, I just used it and although it did start great (better / easier than it ever has) and ran well, after about 10 minutes of use it started losing power and back firing again :-| It seems that I cured one of 2 problems, and when the engine gets warm the main problem comes back to haunt me! I am wondering if I could have a sticky valve, which is either jamming open when the engine heats up.... the engine heating is a red herring, and I just have a sticky valve?? I will try to get hold of a compression tester and check when cold/warm, but can anyone please suggest any other possible causes of power loss when engine gets warm. Thanks C

Hi. I have a similar problem with my 94 LT-4WD. Tried most things listed above, and next plan to take the head off and check the valves & rings. Also mine puffs black smoke when starting, which leads me to believe that I am getting oil in the bore when left for a while. Not much help I know, but wanted to let you know that you are not alone :-) Cheers. C