Got this from my cousin it has been sitting in a garage for about three years he never ran it anymore changed oil new battery went ahead replaced the carb with new one. It starts and idles and runs but white smoke coming out bad tried some of this stuff put in oil help with rings and smoking still smoking. Any idea what should be my next step. Was cheaper owning a boat I think 😂

 

The 400 Auto was one of the best Quads Honda have ever made. Try a new 420 auto in comparison and you will think how far Honda have gone backwards. I wouldn't have put anything in the oil, the transmission is wet clutch and hydraulic drive, anything but the right oil is dangerous to it's health. Smoke isn't usually white, oil smoke is blue and over rich black, but it is easiest for those"in the know" to smell it as oil smoke smells different to an over rich mixture. If it is really bad, get someone to check it and do any work. Or, if you must do it yourself, do a compression test. If below about 90psi take the cylinder off and check it and rings against the specs in the workshop manual. It is a fairly easy job to remove the cylinder in the frame. Also check valves and fit new valve seals in case they have been leaking oil.

 

thanks I’ll try that this weekend