1978 ATC Honda 70 carb trouble

[spitnale01]

I need help with carb. Can only get this thing to run with choke on. Cant find any leaks, Replaced with new head, valves and cam, new carb, and new gaskets, set tappets and still only runs good with choke on. What else can I do? Very frustrating. Thank you!!

 

[Richard Trotter]

I have heard those early hondas have a ceramic isolator between the carb and the head. They are easily cracked if the carb is over torqued, creating a intake leak...

 

[mrtwister]

yes sir ., and if that's not the problem .. you may have to jet it ... fattin it up a little .. theres so much ethinahol in todays fuel .. makes stuff run way to lean ..might have to raise needle one clip and go up one or two sizes on main ..

just a suggestion ..

also im sure you probably cleaned tank and petcock screen already .. ?? if its not flowing good might be starving for fuel ..

I work on this stuff for a living if I can help in any way ill try ..

theres a lot of very knowledgeable and good people on here... im not trying to say im some kinda engine god ,. just trying to help ..

 

[spitnale01]

I have one of the after market plastic gas tanks on it, I'm assuming its clean. Shouldn't be
any rust. I know there is a plastic insulator between the carb and intake and that is one thing I haven't changed. Thanks for your help. I will get a couple of bigger jets and try. Seems like adjusting the idle jet all the way in or out makes no difference either.