212 Predator bogging while accelerating and backfiring(after firing)

[mflair13]

Hello, i have Recently bought a predator motor for my friend for my minibike in the motor was brand new he never started it the motor the things he did to it is he bought a exhaust air filter he rejeted the carb and that’s about it and now i have the motor.

So i got the motor set in the bike and then i go to start it and it kind of ran weird like not very smooth then i messed with the idle then now it works (did). i rode it around for one day then i relized rhat the clutch was all messed up so i ordered a new clutch for it, that showed up then i rode it some more and i only got it up to 24mph and ofc i want to go faster so i took the governor out and when i did that the cam came off with the crank case plate thingy

Whenever i went to put it back together i lined up the dots on the crank and the cam gears and i re did the valve lash then i went to start it and it took a little bit but it fired up and i threw the clutch on and rode it and now it bogs at full throttle or even half throttle and i can’t go more then half with out it wanting to die, and i forgot to mention my friend said that he bought a jet kit and he said he put the biggest jet in and i wasn’t sure on what size so i bought the jet kit from omb warehouse with the 140 and the .36 and the .37 jets

at first i started out with the .36 jet bc that’s what omb warehouse says so i did and it still bogged down and then i thought it was not getting enough fuel so i put the .37 jet in and it did the same thing then i put the stock jet in and it still did the same thing and just to be clear the bogging and stuff happened before i took the governor off too if you need me to explain anything just ask please i would really appreciate the help

-mflair13

 

[mflair13]

i actually just put in the .36 carb jet in and it ran a lot better but i still can’t go full throttle do you guys think it’s how i have the throttle cable hooked up? i still have it hooked up to the governor arm and it also back fires threw the carb it’s like white smoke mixed with gas

 

[madprofessor]

One look at the linkage connection on top of the carb twisting for you when you give it throttle will show you if it's turning all the way as far as it can go. One look when letting off will tell you if it's fully returning to bump up against the idle screw.
Often as not these problems happen because somebody's using cheap cable and conduit, curving it too tightly, cable not coming straight out of the conduit, spring return not strong enough, twist grip hanging up or tight, and more, causing the cable to not float freely inside the conduit. Giving it full twist of a handlebar throttle doesn't pull the carb all the way open. Letting off completely doesn't let the carb freely close back up.
If that Predator is a 212cc then a .036 jet is a good hotrod jet for it, same thing I'm running. You also need to replace the low jet when you put in the .036, or it'll have all kinds of trouble. Mine's now a .022 low jet. Need to be sure the E-tube was put back in right side up when it got rejetted.
If all of that's right, I'd say your carb's starved for fuel. Partially restricted fuel filter, gas tank not high enough for full gravity feed, etc. My own .036 jet has gravity feed, but that's to a pulse fuel pump. The pump is what feeds my thirsty jet.

 

[mflair13]

One look at the linkage connection on top of the carb twisting for you when you give it throttle will show you if it's turning all the way as far as it can go. One look when letting off will tell you if it's fully returning to bump up against the idle screw.
Often as not these problems happen because somebody's using cheap cable and conduit, curving it too tightly, cable not coming straight out of the conduit, spring return not strong enough, twist grip hanging up or tight, and more, causing the cable to not float freely inside the conduit. Giving it full twist of a handlebar throttle doesn't pull the carb all the way open. Letting off completely doesn't let the carb freely close back up.
If that Predator is a 212cc then a .036 jet is a good hotrod jet for it, same thing I'm running. You also need to replace the low jet when you put in the .036, or it'll have all kinds of trouble. Mine's now a .022 low jet. Need to be sure the E-tube was put back in right side up when it got rejetted.
If all of that's right, I'd say your carb's starved for fuel. Partially restricted fuel filter, gas tank not high enough for full gravity feed, etc. My own .036 jet has gravity feed, but that's to a pulse fuel pump. The pump is what feeds my thirsty jet.

when ever i changed the jet i put in the e tube and it says it’s a size 140 and i currently have the .36 jet in and as far as i can see the throttle is opening all the way and closing all the way and i have springs to make sure it closes all the way

 

[Denny]

You did not loose a lash cap inside the engine when you accidentally pulled the cam did you?

 

[mflair13]

what is the lash cap? i will look it up

 

[mflair13]

You did not loose a lash cap inside the engine when you accidentally pulled the cam did you?

i did not see a lash cap floating around in there i have to take the side cover off again here soon bc my gasket is leaking so i will check for them but where exactly are they located bc i can’t find anything on google

 

[madprofessor]

Here's a link to RBG video on adjusting valves, and he shows you the exact lash cap(s) location. Advance to 3 1/2 minute mark of video, there you are.
If any parts go missing in an engine, they should either be in the bottom of the crankcase, sitting under the valve cover, or down inside the pushrod passage(s).
I lost a circlip off my intake rocker shaft, and it wasn't visible anywhere. Had to buy an extra-small telescoping shirt pocket magnet to fit it down inside the pushrod passage(s), and voila, out it came in 2 seconds with an unbroken circlip stuck to it.
How to Install 18lb Valve Springs & Adjust Valves GX200 / Predator 212 Hemi & Non Hemi Go Kart - YouTube

 

[mflair13]

would that make it so i can’t go full throttle? or it will bog down

 

[madprofessor]

Losing a lash cap off of the valve stem would be like setting the valve lash to a ridiculously wide setting, maybe even enough to let the pushrod jump out from under the rocker, or hang up there and get bent.