Greetings to all this forum was extremely difficult to find,I am very encouraged for my sake to have gotten here though because I have just purchased 2 redcat mpx 90 for my boys .They do love them as much as I truly love to see the smiles on there faces when they ride them.I do have some reoccurring issues that I could really use some help with the first being all the loose hardware on both machines but the one that has me troubled the most is there inability to stay running from what I can only see as being dirt in the carburetors,I have installed filters even before I had them ridden and have found still small amounts of debris blocking the pilot jets to the point to where they will not stay running or start,the weather is very cold probably adding to the issues .Any help would be greatly appreciated by myself and my sons,Also until the first set of problems they both ran really well ????? thanks for any help given

 

Have you changed the spark plugs? If you have not try an NGK C7HSA. If that does not work the air fuel screw my be out of wack. Its the brass colored screw next to the idle screw. A good starting point on the screw is to screw it in till it gets snug and back it out 3/4 to 1 turn.

 

nicko31,
Have you looked at the thread about adjusting the carb from 2manytoys? It sounds like it is very helpful. I bought an MPX90U for my son this past Christmas. It ran fine the first time or 2 then it was almost impossible to start. When I did get it started, you could ride but if you stopped, it would cut off. I took it back to the dealer at the end of January and they said the jets were clogged. They said it was dirt but after reading 2manytoys' post, it might have been the gelpac. I think I will try the spark plug next if I have anymore problems.

 

nicko31,

First off on any Chinese quad you have to go over and lock tite all teh nuts and bolts that you can get your hands on. This will help for alot of trouble free riding. This is a must. What kind of filters did you put on the quads? Sounds like they are not doing the job. Let me know what you used.

 

actually it's the filter in the top of the fuel petcock which got clogged and I did find small amounts of dirt at the bottom of the carb bowl,the filters are small white plastic units that are used for lawn mowers.

 

Oh ok the fuel filter. Is the fuel cap on tight? Do your kids ride in dusty conditions?

 

yes the fuel caps are tight> I have one that is running well the other is not. I changed the carb because I had an extra and it made no difference .When I take off the white bowl at the bottom of the fuel petcock it is always full of small particles that look like rust and metal. If I take the carb off it will run for a short time and then run ruff again. the weather here in western N.Y. is 20 deg Fahrenheit,not a speck of dust anywhere only snow.I'm at my Witt's end with this thing.

 

Did you try to drain the tank and wash it out. Maybe at one point you did put bad gas in it or something is not sealed right.

 

I'm going to try and wash it out again and replace the fuel .I'll let know how I make out .thanks[img]i/expressions/face-icon-small-smile.gif[/img]

 

Well I am still having a little bit of trouble with one of these quads,debris getting into and plugging the carb pilot jets.I've washed out tank with soap and water, but after only a few minutes it starts to run poorly again.On the other machine I adjusted the handlebar mounted choke to start the quad which it would but after it started and ran it too started to stumble so I turned back the choke and it ran well again.Very frustrating to say the least sad for my little guy. Also has anyone ever used white coffee filters for gas??