Had my Mit in Colorado last week for an elk hunt, did great except for a long, very steep and rocky climb on the last day. Altitude was in the 8500' range and it lacked enough power to lug the load over the rough terrain. Ended up taking the air filter out and some of the weight out before it would make the last hump. So, any suggestions that might help before next year? Looks like mine has a cat converter on it. Will it help to take it out. Also looks to have a O2 sensor just behind the cat converter, does it have to stay if I take the convertor out? Any high altitude jets available for the carb system??? Any help will be appreciated.
You can take the cat out, since I assume it doesn't need to meet emission regs.. The sensor behind the cat should only be a temperature sensor, just to let you know if your converter is malfunctioning and/or clogged. (Although this depends on the exhaust system..if the cat is located just beneath where the exhaust tubes leave the head..it may be an O2 sensor)..if the cat is located farther down towards the back of the truck..should be just a temp sensor. O2 sensors usually are located where all the primaries meet, to get a good whiff of all the exhaust. Most Japanese mini trucks weren't designed for such altitudes..EFI systems might be able to keep up, but not an aging carb. Only thing I can think of is to switch to a motorcycle carb (like an 883 harley??) which would have more parts, options, information for proper jetting. I'm running a similar one on mine.. Don
If only they had EFI...those cheap...sorry, it always gets me why these trucks were so late into getting EFI. In the land of technology...anyway! I always thought a KLR650 carb would work great...they are 650cc, but single cylinder? Would that theoretically work? I've always thought about it, but never really looked into it. My KLR is easy as pie to re-jet and get running top notch, mind you, you'd have to hook up a manual choke, but that may not be a bad thing... -mark
Most Japanese work vehicles (even new ones) use carbs simply to keep costs down. Our shop purchased 4 new delivery vehicles (2005 models..in 2005!)..and all had carbs. Apparently much cheaper to make if you already have stockpiles of old carbs around the factory. You could use your carb..it runs on the same principle as any other one..as long as it's off a 4 stroke, and similiar displacement. You may have to mess with jetting and exhaust tuning quite a bit to get it right...and fuel pump pressure, as I assume it's probably gravity fed. Honestly, I thing you could run 4 Briggs and Stratton carbs if they are off 10-12 hp engines. Top end may suffer, but THAT would look original!
