Bought two 49cc 4 wheelers for my 7 and 10 year old sons. The 10 year old's runs good - no problems at all. The automotive parts store where they were purchased said the "guys in the back" loved that little 4 wheeler. When they first came in they checked it out and rode it all over the place. The 7 year olds 4 wheeler has had problems from the minute we brought it home. We don't live on a big farm, we have two acres of lawn for them to ride on. The third time he rode it the bar to which the safety switch is attached fell completely off the 4 wheeler and was being pulled along behind the bike until he stopped. This safety switch is designed to shut the engine off if the rider falls off. It is connected to a strap they wear on their wrist and should they fall off it jerks the switch out thus shutting off the motor. You can imagine our surprise when the bar, switch box and all fell off the bike and the 4 wheeler continued to run before the little rider stopped and shut off the engine to check out what he was dragging behind him. So we picked it up and set it aside and let him go on riding. He rode it again the next day and all was well. The fifth time he rode it, we started out having trouble. The 4 wheeler acted like it didn't have any power. Every time he gave it gas while riding it would die. And after about 10 minutes of that he was tired of trying to ride the thing. So as we put it up to let his grandpa look at it when he got home the wheels locked up so that it wouldn't move. We had a limited 90 day warranty on the thing and were still well under that so we loaded it up and took it back to the store where it was purchased only to be told they don't work on them and to call the company. That proved to be a giant waste of time and energy. We were directed to take the 4 wheeler to a certified Baja mechanic for "diagnosis". There aren't very many of those around so it was quite a distance to drive. When we got there we were told that he had been given the okay for 1 hour to look at the bike and see what was wrong. When he called the company back he told them that it was the cleanest bike he had seen in a long time. Except for the battery acid dripping down onto the engine and the wheels being locked up and the bar holding the safety switch was off. We left the bike with the mechanic who called us in three days with a bill of $140.88. That was for a new battery, bolts to reattach the safety switch/bar, cleaning off the battery acid, bolts for securing the exhaust we didn't know was even loose and repainting what the battery acid destroyed. The mechanic never was able to determine why the wheels locked up but they haven't been a problem since we brought it home (2 days ago). What did the warranty cover? The hour to diagnose the problem and rehooking up the wires of the safety switch - which still doesn't kill the engine if you disconnect the switch from the switch box as if falling off the bike. The mechanic told us that Baja attributes every problem to "abuse" - which of course would not be covered under warranty. As to why all these bolts were loose and things were falling off? It was "our responsibility to make sure all bolts and parts were secure prior to riding the 4 wheeler each time". The battery? "we must have put it on a battery charger that was too strong" - He hadn't ridden it but about 3 1/2 hours the entire time he had the thing - and the battery never needed charging the entire time! Remember the 10 year old? His 4 wheeler is still going strong. Not one problem. We are now just over the 90 day "warranty" and at this minute both 4 wheelers are running fine. It is a shame that after spending a little over $700.00 for something like that - that the store where it was purchased and assembled nor the company that made it would stand behind their product. We purchased extended warranties but for what! The original warranty isn't worth the paper it was written on. Whatever you do - do not purchase a Baja Motorsports product unless you know how to work on them yourself. What a waste! I am a single mother with 2 boys and the purchase of those two 4 wheelers was only made after a lot of scrimping and saving. The mechanic's bill was paid by the grandpa or it would have had to sit at the mechanics shop until I could get the money to pay for the repairs. I sure wish I had looked up the reviews on this company before I bought anything.