My brother has an 04 Rancher A/T 400. It is so weak you have to get a run at it just to go up the ramps to load it in the back of the truck. The top speed is only about 32 mph. It won't climb anything. Does anybody have a clue to what it might be. I know it could be alot of different things, but like any other quad it has certain problems that only the Honda owners no about.

 

You've checked all of the regulars right? Air filter may be extremly dirt. Could have a shortage of fuel (Fuel filter clogged, hose kinked, etc.)

A friend of mines Foreman was to this point because tehre was a mouse nest built of insulation in the aribox.

Not thinking you have a lack of knowledge, just thought you should start at the basics.

 

We cleaned the air filter, got the mud out of the air box and got all kinds of dirt and sut out the the plug in the exhaust. They were all pretty dirty, but we did all that and it still ran badly. What else can we do? It doesn't cut out or anything it just has no power. He has 27' 589's on it and we no that it really bogs it down but not this bad, like I said it won't even go up ramps without a run at it.

 

Did he ever have the ECM and clutch changed? There was a recall on the 04's for these two items.

 

Not sure if he did or not, I'll ask him.