Hey guys, new to the site and new to mini trucks! Got this guy and the previous owner had done some mods and it runs pretty poorly so I'm trying to figure it out. I put in new plugs and plug wires and the cap and rotor seem all right but it runs pretty poorly. ( Idles okay and rev's all right but under load lacks power completely and the idle tends to stay up once you start driving until it bogs down and dies) There is an aftermarket 32 mm carburetor on it, but I'm not sure it's set up right. I'm getting ready to tackle vacuum leaks and jetting on the carburetor, but the first thing I noticed that I have a question about is what appears to be a breather on the motor that vents back into the cold air intake between the air filter and the carburetor. The tube runs from the top of the block and comes into an inlet that's formed into the cold air intake tube. My question is this: there is a ton of air coming out of that tube so it's forcing air at a pretty high rate into the cold air tube, so I have to turn the idle way up and I'm guessing over fuel the carburetor to make up for all of this high volume air being forced in to the carburetor. Should there be a ton of air coming out of that or is that a sign of excessive blow by from the cylinder rings? Secondly, is there a PCV valve location to balance this discharging air because I've not found that yet? Sorry lots of questions but I'm starting to dig into this guy and any help from experienced folks who have worked on these would move me ahead quickly. Thanks in advance!!
Sounds to me that you have a worn out engine and a blocked PCV valve. The tube you are referring to should be the clean air intake TO the engine block. You should find another line FROM the block to the intake manifold or at the base of the carb which should have a PCV valve at the block end. Remove the oil filler cap to verify. This will allow the excess blowby gases to blow out the oil fill hole instead of the intake to the carb. You also need to do a compression or leakdown test to verify the condition of the rings & valves. Fred
Thanks Fred, that is super helpful!! Just digging into this guy and trying to get my arms around what I've got. Compression/ leakdown test was my next diagnostic after checking PCV and vac leaks, I'll probably move it up. I'll keep you posted, might be a week till I can get into it again, but your input is really helpful!!
