Yesterday I took my big bear out for a ride for the first time in a while. The problems started when I was at about 3/4 throttle and the engine started to bog and sputter, I realized that the gas was low and thats what appeared to be the problem, I switched the tank over to reserve and it started right up and took off with no problem and ran that way for about a mile then the same thing started to happen. It will run just fine until I get to about half throttle then it bogs, sputters, and back fires. I replaced the spark plug and nothing changed but thats all I have done so far. I was wondering if anyone has any ideas on what I could check out on my own, I don't wanna bring it to a mechanic yet if its simple, but my idea is that its the carb or the fuel lines. I'm not the most experienced with carbs and don't really wanna mess with it, by the sounds of it most mikuni carbs are junk though. any ideas?

 

Did you put more gas in it? If yes then i would suggest cleaning the carb....
if no.. then fill it up first then go from there

 

yeah Filled it up and took the fuel valve off of reserve and put it on "on". I plan on cleaning the carb this weekend probably, just kinda weird that it all started with running out of gas. the only thing that i can think of is that it sucked some crap from the bottom of the tank into the carb, I didn't notice a fuel filter that i could check to see if it was clogged, so i'm assuming it doesn't have one.

 

Yeah i dont believe it has one and if you got it that low God only knows what you sucked up into your carbs I would definitely start there

 

There may be a filter "Screen" built into the fuel valve. Check it for dirt.

 

get a can of Seafoam and run it trough the system. you can get that at most auto parts stores. auto zone sells it here.

 

Clean the carb and fuel lines with some sea foam, take the tank off and clean it, check your petcock for debris, and install an inline fuel filter. Also, check your choke cable real well.

 

Thanks for the tips guys. So if I take the carb apart and clean it, will i need new gaskets or do they usually hold up when you tare it apart?

 

Sweet! went to the store and got some sea foam and added it to the gas, ran it for about a mile or two and it cleared it out. I knew about sea foam more as a fuel stabilizer not as a carb cleaner, but it looks like you can put that stuff in just about everything. Gonna clean the tank and add a fuel filter tomorrow. Thanks for the tips guys!

 

seafoam works amazing you wouldnt believe the stuff seamfoam can cure, you can use it on your car, pour 1/3 in oil 1/3 in gas tank and the rest let a vacuum hose suck the rest up into the fuel delivery system, i use my hose off the brake booster on my truck, its one powerfull cleaner and it makes a cool smoke show lol.