So I bought a 1899 yamaha moto 4 from someone off marketplace he said itd bog down under throttle so i figured it was a quick carb fix so i went ahead a bought it and brought it home he had taken all the plastics off so i put them all back on and got screw around with the carb from cleaning the bowl and taking a safety pin to everything it would idle like he said but still bog down under throttle so on one of these threads its said to reset the valve so i did and i took the top off and made sure my valves set right and reset the valve and when i tried to start it up it acted dumb and would back fire( i had the exhaust off seeing if maybe it was a result of it being plugged up) and blow smoke not a lot kinda like it was tryna start but it couldnt i added a fuel filter even tho i didnt have the room to do so i dont know if its a carb issues or maybe my valves are still off

 

Did you set the valves at TDC on the compression stroke? Poking about with a paper clip on a carb is a waste of time. Blow jets and the holes they came from out with an air line and don't alter the idle mixture screw unless someone else has been messing with it. Check CD diaphragm hasn't got holes in it. Check the rubber inlet manifold for cracks, Yams are notorious for this and most likely to fail when you are pulling the carb off.

 

I did check valves at Tdc and I used the paper clip to check some of the smaller things since I have to order a new air compressor. I’ll get a squirt Bottle and check around the intake boot and see if I can see anything

 

I ended up not finding any cracks on the intake boot I’m kinda thinking maybe it’s due to low compression from either the valves not sitting right or from the piston ring being shot I have tore down that far yet to check the rings I may do that later today

 

Do a compression check before taking the engine apart.

 

sorry for the really late responds
i ended up just replace the whole top end and it ran fine with some minor fixes i also got a carb rebuild kit and a new intake boot then i was riding and i forgot to tighten the camshaft spocket down to 45ft/lb so it broke the camshaft i got a new one order and when i put it in everything went south i dropped the chain into the very bottom so i had to tear it down but i got it all put back together and it wouldnt run but would back fire and carb foul my plugs so i reset the carb i pulled the main jet needle out and brought it up one which was supposed to make the mix leaner but it still wouldnt run i would get a quick second run but wouldnt say longer then maybe 5 seconds so i cleaned the carb again and this time before i put it all back together i primed the carb pump which did make the sprayer work. at this point everything points to a fuel issues but i suck at that part of engines