professor
Active Member
The engine came stock with real lean jetting.
I started opening the main jet untill it would stop bogging when cracking the throttle. This was with the stock exhaust and no aircleaner.
I run a free flowing intake and exhaust now, but kept the jet size the same. Used a number drill to open the main jet to (I think) 33 thousandths.
The idle jet stock is 15 thousandths, I opened it to 17.
The gokart guys say 21 idle and 39 main jet size.
Seemed too much to me, but because I still have to start with the choke on (unless the engine has run for a while), I opened the idle to 21.
Big mistake- blubbering rich idle was what I got.
Not being able to solider it up (with the jet incased in plastic).
I used some seal-all glue with a guitar string stuck in to size it back to 17, until I can get a new jet.
The HF 79 was similarily lean, I left the idle alone but opened the main jet about 3 thousandths. I assume all new motors are too lean.
Just a heads- up to anyone with or getting one of these engines.
I started opening the main jet untill it would stop bogging when cracking the throttle. This was with the stock exhaust and no aircleaner.
I run a free flowing intake and exhaust now, but kept the jet size the same. Used a number drill to open the main jet to (I think) 33 thousandths.
The idle jet stock is 15 thousandths, I opened it to 17.
The gokart guys say 21 idle and 39 main jet size.
Seemed too much to me, but because I still have to start with the choke on (unless the engine has run for a while), I opened the idle to 21.
Big mistake- blubbering rich idle was what I got.
Not being able to solider it up (with the jet incased in plastic).
I used some seal-all glue with a guitar string stuck in to size it back to 17, until I can get a new jet.
The HF 79 was similarily lean, I left the idle alone but opened the main jet about 3 thousandths. I assume all new motors are too lean.
Just a heads- up to anyone with or getting one of these engines.