I just put together a predator 212 deleted gov and oil sensor. Arc +.04 rod flat top piston .045 firering head gasket. Light polish on head from watching youtube. Lapped the new valves as well. Brownbox 275 cam lifters push rods and champion rockers lash at .002. flywheel with #8 key. Ngk gapped at 28 .Vm 22 carb. Seems to be rich and sputtering with smoke like it's to rich. I have went back and forth on pilot jets from 20-30 with a 25 I can keep it running at idle intake side screw is about 2 turns open main is currently a 120. It won't start with a 20 or 30. I can't seem to get it to idle correctly and it sputters and smokes smells rich. O yeah 89 octane. What am I doing wrong.
Help and suggestions on a build I'm trying to tune
- Thread starter stjtank
- Start date
panchothedog
Well-known member
- Messages
- 2,845
- Reaction score
- 3,847
Put the stock carburater back on with a .036 main jet and a .020 pilot jet and it will run fine. You might give up 2 or 3 mph on the very top end, but at least your engine will run properly. I have been down the same road that you are going down, and out of three of those Chikuni knock off POS I have one that runs as it should. I have 5 modified predator or clone engines, simaler to yours. I have the one Chikuni one real Makuni ( expensive but they work good ) and the other 3 run the stock carburater jetted as explained above.
bob58o
SuckSqueezeBangBlow
I didn’t hear any mention of the use of a choke / enrichment circuit.
Hellion
Moderator
- Messages
- 8,864
- Reaction score
- 3,874
Hell, it sounds like he's running on choke by some parts of his description. Using choke to start is imperative, sometimes even on warm engines according to A/F mixture...
25 pilot jet 1 3/4 turn open starts on first pull now timing was off I used a degree wheel no key after lapping. Running great at idle not concerned with top end my jets are rated in 120 125 ect .036 would be what
Used a degree wheel and corrected time the advance listed on my Amazon one was way off.
Timing issue trusted flywheel manufacturer used a degree wheel and when keyless
panchothedog
Well-known member
- Messages
- 2,845
- Reaction score
- 3,847
Glad to hear it's up and running good. I've never had a flywheel off so much that it affected the way the engine ran. But then I have never used an Amazon flywheel. Guess you really do get what you pay for.
panchothedog
Well-known member
- Messages
- 2,845
- Reaction score
- 3,847
A .036" is the size of the hole in the jet. 36 one thousandth of an inch. But this pertains only to the stock style carburetor. I thought that I made that pretty clear in my post. No idea what the size of the jet is in the carb you have. But once again, glad to hear it's running properly.
Absolutely so the Amazon one is sitting in a box I got an arc and have there video saying check it anyways I did
panchothedog
Well-known member
- Messages
- 2,845
- Reaction score
- 3,847
Was the arc flywheel any closer to correct timing than the one from Amazon?
If the factory ( Chinese quality control ) messed up when they cut the slot in the crankshaft for the key, it would also throw the timing off.
If the factory ( Chinese quality control ) messed up when they cut the slot in the crankshaft for the key, it would also throw the timing off.
With the arc I showed 30 with a degree wheel also marked and used a timing light. Definitely better fired first pull but still playing with jets pilot is obviously to big
panchothedog
Well-known member
- Messages
- 2,845
- Reaction score
- 3,847
Checking with a degree wheel and finding it at 30 is really close. They advertise them to be at 32. Makes me feel good about the several that I own. Thanks for the info. Hope your jet hunting goes good.
Denny
Canned Monster
You can tune a carb. But you can’t tune a fish!