Hey everyone, I am new with mini trucks. Like super new. All I know is I have a Mitsubishi Mini Truck that is late 80s early 90s and that it has the 550cc 3cyl engine. I bought it from a guy and he had been having issues with it. It would barely run. My friend who is a mechanic got it going but it seams to be SUPER weak. It starts good and idles great. Upon staring you can't rev up or it will bog down. After you let it warm up you have to feather the fuel to get anywhere. This is the case from 1st gear to 4th. And losses it's momentum in 4th. The last owner had swapped out the original carb for a S&S Super e Harley carb for unknown reasons. It seams to be much simpler then the stock carb so that might be why. I'm trying to figure out how to get top end power and what might be the problem. My friend told me that these trucks were built to drive on flat ground in Japan so they won't have a lot of power but I disagree. It won't even climb an incline. I might add that it doesn't smoke. Any help is greatly appreciated. Thanks!
Of coarse you checked the air intake and catalytic converter to confirm their not plugged. Then you checked timing . pain in the ass but you can try advancing your rotor to confirm. these trucks also need their valves readjusted every 5000 km to .004 and yes these trucks usually can climb anything you point them at. Presumably the new Harley carb did work. Me I would try and ask previous owner who installed carb if that was the case. All in you should be able to confirm what the problem is on a sunday Tony
Thanks Tony. I will have my friend check into all of that. I'm not sure of what all he has checked. I do know I bought a new air cleaner for the carb and he installed that. I'll hopefully be able to get it lined out. I figured they could atleast climb small hills. Thanks.
I'm not sure about other carb fit ups but if you have to buy a new or rebuilt original you may check into a propane kit....I'm interested (just for the heck of it) in them but can not find a whole lot of info.... Also what kind of wheels / tires do you have? I'm looking for some for my 98 mits..
curious to know if you have figured anything out. i truck has a very similar issue where it just bogs under throttle. i have cleaned the cap / rotor and changed the plugs. it starts and idles great. the compression is great. im going to check the cat next to see if its plugged.
I would check the quality of the spark should be bright blue. Might have weak coil and or bad wires. Also check and make sure the accelerator pump on the carb is working.