Stage 2 Predator 212 Will not start nor run right. Please help me!!

#1
As for some background- this is my first ever predator 212 minibike build. I installed a Stage 2 kit(Billet Flywheel, rod, cam, 22lb springs) a header pipe, a Mikuni VM22 clone, and a torque series (all from GPS). Now i'm to the point of trying to run it. So, I have checked and for sure have: Spark, my timing is correct, and I have compression. I know my O-ring is lined perfectly on my carb as well. It leads me to believe it's my carburetor either faulty or not tuned right. It will ONLY start when I give it a little throttle, is on choke, I have to pull the start cord very hard, and the idle screw is turned in a bit. As soon as I put the bike off of choke it will turn off IMMEDIATELY. I have ordered some main jets from amazon, but CANNOT find any pilot jets that are the same as my VM22 clone. The main jet that came with it is a 130. The pilot jet it came in is a 38 (even though GPS says in the description that it comes with a 16??). What are my options to get this running right? I'm desperate to get it running, if anyone could help out it would be greatly appreciated. (See photos attached)
 

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#2
Have you checked your float level?
Have you opened the drain to verify PLENTY of fuel flows through the carb?
Is the main jet plugged with Chinese manufacturing trash?
Is the tank full? (sorry, I had to ask)
Valve lash set correctly? I ask this because you stated you have to pull very hard.
 
#4
Have you checked your float level?
Have you opened the drain to verify PLENTY of fuel flows through the carb?
Is the main jet plugged with Chinese manufacturing trash?
Is the tank full? (sorry, I had to ask)
Valve lash set correctly? I ask this because you stated you have to pull very hard.
How’s it going man. Thanks a lot for the reply! I have not checked ANY of those and will be checking tomorrow and updating you. The valve lash is set to .003 on both sides. Can you elaborate on the float level,and chinese trash part? And yes, the tank is full! When I say pull hard, i don’t mean it gives like overpowering resistance, more it won’t start unless it’s pulled hard enough if that makes sense.
 
#5
Did it EVER run properly before you installed your "Stage 2 kit"? When you called GPS to report the issues you are having what did they tell you?
Michael
Hey man thanks for taking the time to reply. I never ran it before. It was a brand new predator 212 from Harbor Freight and I just took it fresh out and installed the new parts. Didn’t think to run it before, first ever engine work, stupid mistake.
 
#8
The junk I refer to is metal scraps from drilling and machining operations, being left inside the carb. The first couple of times you start it, those tiny left over pieces of brass hair can plug your jets and passages. See if you can look through your main jet. You should see light through the hole.
EDIT your manifold might not be flat. It can be checked and trued with a FLAT surface and sand paper. Go slow. That is the leak @Minimichael
was warning you about. Good call, @Minimichael
Something is not right with that joint.
 
#10
The junk I refer to is metal scraps from drilling and machining operations, being left inside the carb. The first couple of times you start it, those tiny left over pieces of brass hair can plug your jets and passages. See if you can look through your main jet. You should see light through the hole.
EDIT your manifold might not be flat. It can be checked and trued with a FLAT surface and sand paper. Go slow. That is the leak @Minimichael
was warning you about. Good call, @Minimichael
Something is not right with that joint.
I’ll check the holes tomorrow. Can you elaborate on the manifold part. Thanks.
 
#12
Scrape off all of the gasket.
To check and true the manifold, get a piece of glass, metal, flat cutting board, something stiff, and a piece of fine sand paper.
Sandy side up on the board, and slowly scrape the mating surface of the manifold on the sand paper. The high parts will look dull and the low spots will still look shiny. Do that until it is perfectly flat and uniform. New gasket and tighten carefully.
 

SAS289

Well-Known Member
#17
do you have anywhere where i can buy pilot jets? i’ll attach a photo but I cannot find any similar to the ones in my Mikuni. GPS only sells one other pilot jet. (stock on left, amazon ones on right)
Is the pilot jet on the left in the picture from your carb? If it is GPS sells those. You will not find them on Amazon or anywhere else as far as I know.

I don't like GPS. But if I wanted pilot jets for my VM22 clones I would have to buy from them.
Pilot Jet, Aftermarket 22mm Mikuni Carburetor (22PILOTAM) (gopowersports.com)
 
#18
THIS is a photo of it before i put the carburetor on. I’m assuming that is very bad then?? I should go back and scrape it all off.
Clean the face of the intake manifold completely check to be sure its flat. A 6 inch machinist ruler has a good flat edge you can set it against the manifold you shouldnt see any light between the face of the manifold and the edge of the ruler. Light shining through would be a low spot that air can pass through. An air leak cannot be fixed by any anount of jet changes.
 
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#20
Clean the face of the intake manifold completely check to be sure its flat. A 6 inch machinist ruler has a good flat edge you can set it against the manifold you shouldnt see any light between the face of the manifold and the edge of the ruler. Light shining through would be a low spot that air can pass through. An air leak cannot be fixed by any anount of jet changes.
I will go ahead and clean the it as much as I can, thanks a lot.
 
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