Hey all, I'm new to the forum here but have been using this site as a resource for years now since i bought my Honda Acty a few years back. I'm reaching out as the company I work for has acquired 10x mini trucks for our company to putt around our property with. Since I've had so many of my own over the years, and company wide, I'm the most knowledgeable on them, I was put in charge of servicing and maintaining these awesome trucks. we have 3x Hijet's, all S110P. 1st is a 5mt carbureted 4x4 w/ Hi-lo, another is a carbureted 3at 4x4 and the 3rd is an EFI 3at 4x4. ill refrain from mentioning much about the Honda's on the hijet thread for now but my main point for reaching out is that that the 1st Hijet mentioned is really giving me a run for my money, especially since my forte is working on the Acty's. currently what's going on with it is that when anyone starts the truck cold it'll idle fine but the moment you so much as sneeze at the gas pedal the engine runs away to something like 4k rpm. I've narrowed down its cause to be related to the large vacuum solenoid on the bottom right hand side of the carburetor (see photo, white arrow pointing up to it) as if i force the throttle closed via the cam on the left side/rear half where the throttle cable links up it settles back down and the vacuum solenoid gets a grip again. any help is greatly appreciated as I'm nearing my wits end here, though from what i can gather, i think something is adjusted out of whack... thanks guys!!
here it is. also here is a YouTube link ( )to a video of the truck doing this exact thing. it will do it more when cold but even when warmed up it will still do the same thing
Update: So it seems that the issue at hand is the truck's carburetor was stuck in both choke mode and off of choke at the same time if that makes sense and I'll elaborate on this. Unfortunately I cant seem to quite get a good photo of the issue but I will try to be as descriptive as possible. So if we're looking at the rear half of the carburetor (assuming orientation is the same from the photo above) just below the wax motor there is an adjustment screw there too that has yellow thread marking painted onto it. its quite difficult to see as its practically upside down under the carburetor but it is there at least in our 2 carbureted trucks (both S110P). Our first truck that warms up and idles fine when cold and warm responds to every adjustment screw when turned left or right when both cold and warm. The problem truck would idle smoothly and start easily when cold but when warm it would refuse to open the choke fully as if the wax motor wasn't there and would only open upon flooring the truck for a solid 5-7 seconds where it would sputter very bad before it would eventually and very suddenly rev up and sit at 4k rpm then settle down within 10-20 seconds. Upon inspection of both carburetors it was noticed that the previously mentioned wax motor adjustment screw (which seems to be for adjusting how soon or late the wax motor starts kicking off the choke) was bent entirely clear of the wax motor's plunger so when the truck was cold it would start A-Okay but as soon as the wax motor expanded it wouldn't push on anything and it would still be in choke while the vacuum solenoid up top would fight to try and open up the choke butterfly to let a good flow of air through. hopefully this makes sense! And I'm sorry if it doesn't. if anyone has more questions about what I'm talking about please ask and I'll do my best to answer, in detail, what I mean.
