hi i recently aquired an older yerf dog spiderbox with the howitt 150cc engine not running and has been sitting for some time thanks to the help from the posting i have gotten it to run... but still need help, the cart will run only if the pedal is to the floor but it will not rev up and sputters and runs as if the choke were on? after checking the choke and the diaphrams all are ok if you look in the carb there is a float type plunger hanging down with a rod from the bottom of it if you manually raise this it will race the engine up while the pedal is still floored? by accident i started it with the vacuum line off from the intake and it actually idled!!! and it will rev up by the pedal from an idle there is a hesitation and when the full throtle is releaced it will stall but will start up ok also i put the air box back on and it will idle but not rev like it does without an airbox this is even with the vacuum line still off if i hook it back up with or without the airbox it will only sputter at wot also will only start a wot seems to me like its starving for air in the mix can anyone please help thanks frank

Kinda sounds like to much fuel So when you take off the vacum it sucks more air and levels out. Your float might not be closing the needle all the way

thanks im new to these small engine toys if the float is not closeing all the way wouldn't the carb pour out gas when the engine is off? or is it only a problem when running? how should i try to repair this?i remember reading in a post that the float must be level when would this be? thanks

You are correct. It should dump out the side of the carb. It just seems that when you let in more air it clears up. Have you cleaned the carb? You should check the valve gap as well.

yes the man i got it from cleaned it several times and i my self have cleaned it and the tank once there is no fuel spilling from any where running or not is it possible that the vacuum is to weak to pull up the plunger (i don't know the name) inside the throat of the carb causing it to run as a choke was on?? i was told that the rectifier was the reason it wont run right (previous owner) but as far as i know the rectifier is for charging and lights? there is the white wire going to the rectifier in the plug that has at some point gotten hot enough to start to melt thae plastic plug but it is still working i just wasn't sure if im looking at the carb as the issue if itciuld be electrical?

have you pulled the spark plug out and see how it is running.

also what about the valves have they been adjusted in a while or ever adjusted.
most usually valves will cause hard starts but i had a exhaust valve sneak up on me and was out of adjustent, to tight not closing all the way.it would start wright up wouldn't idle though missed and carry on when trying to give it gas.
i would have bet it wasn't a valve but after going through and over everything else i check the valves and found my problem

pud

On the Yerf, the rectifier is only for battery charging. Ignition, choke and lights run directly off AC from the stator. If the electric choke is working properly, look for leaks in the intake and exhaust.

I would pull the plug as pud said. If it's black to much fuel, white is to much air. This will tell us what area to focus on. The vacume petcock will stop fuel flow when the motor is off but if the needle was'nt closing it would still empty the line out

It could be that the petcock is'nt letting the fuel flow as well, but it seems that it wants more air not more fuel.

thanks for all the ideas you guys are great the plug was black before i cleaned it it is an ngk plug (not sure if that matters) it wasnt loaded bad just a couple wipes with some 400 grit and looked like new. i have seen so many posts with intake issues i decided to check mine it is showing age but doesnt appear to have any crack through it the o ring is fine i thought i may have left the bolts loose so while it was running i put my ratchet on to check for tightness and funny thing i had the ratchet set to loosen and with one turn loosening the intake bolt by accident the dog ran awesome the carb was actually shaking around and this ran great... i dont get it starving for air?? i had a simiylar problem on an old vw 1600 and the carb was rebuilt no change come to find out it was worn out and parts were no help does anyone think this is the case hear? i saw a link to e-bay for a carb for 35.00 sounds real cheap maybe i should take a leap this has been around for a while i dont know even how to determine what year it is?? does anyone know how many turns out the air/fuel screw should be maybe someone adjusted that but to me it seems like that is a long shot thanks to all