Predator 212 no start

[JG122017]

Hello. New to small engines however have turned wrenches on bigger ones for years. I recently was given a go cart with a predator 212 non Hemi was told the only thing upgraded was the clutch, and the carb. It ran fairly good but would stutter bad when cornering (obviously low oil sensor related as it was still hooked up) so I done some research and finally took the oil sensor out of the block completely, same with the governor, replaced the stock flywheel with a billit one and as I reassembled I very meticulously made certain the piston remained TDC, the notches in the cam lined up to the notch on the crank and the flywheel magnet was lined up with the coil. I lubed the valves and made sure they were set and made sure the rods weren’t bent and reset valve lash as close as I could to .005“.

i then reassembled the entire thing with the only other thing being replaced was the fuel line from fuel tank to carb (old one was dry rotted) went to fire it up and nothing. nothing except backfires and exhaust pops when holding throttle open. any leads on where to start checking? Is there something I missed

 

[Denny]

Did you put the lash cap back on the exhaust valve tip? You sure cam is lined up? .003 is more than enough lash. Getting fuel? Spark at the plug?

 

[JG122017]

It is getting strong blue spark, I’ll double check the lash cap when I get home, and it’s getting fuel at least to the bowl. I did notice a good bit is puking from the butterfly in the carb. and I’ll add every time I pull the plug it’s fouled out no matter how lean I set it

 

[JG122017]

It is getting strong blue spark, I’ll double check the lash cap when I get home, and it’s getting fuel at least to the bowl. I did notice a good bit is puking from the butterfly in the carb. and I’ll add every time I pull the plug it’s fouled out no matter how lean I set it

Also forgot to mention I do know the cam and crank are lined up where the dimples meet

 

[bob58o]

Upgraded carb? To what? What size jetting?
Stock exhaust?

Which flywheel?
Flywheel installed with key?

 

[JG122017]

Upgraded carb? To what? What size jetting?
Stock exhaust?

Which flywheel?
Flywheel installed with key?

Unfortunately that’s the unknown to me. I got the cart from my brother in law and he said it was upgraded but couldnt Remember what the dude he got it from said it was and as far as the fly wheel it didn’t come with a key so it’s got the stock flywheel key installed

 

[bob58o]

Unfortunately that’s the unknown to me. I got the cart from my brother in law and he said it was upgraded but couldnt Remember what the dude he got it from said it was and as far as the fly wheel it didn’t come with a key so it’s got the stock flywheel key installed

Take a picture of the carb and air filter and exhaust.

My first thought is too rich carb jetting.

Second thought was spark happening at wrong time, (which would be a broken flywheel key).

 

[bob58o]

Valve lash was set when both springs fully relaxed. TDC of compression stroke (not on the bump for compression release, not TDC of exhaust stroke)?

EDIT : I think if the crank and cam dots were aligned when setting lash, that means you were close to TDC on compression stroke. So just make sure lash wasn’t set on the bump for compression release.

if you watch the valves move while turning the engine over by hand… you can see a small movement of the exhaust valve after the intake valve closes. This is the compression release. Turn the engine past this bump, then set lash.

 

[JG122017]

Take a picture of the carb and air filter and exhaust.

My first thought is too rich carb jetting.

Second thought was spark happening at wrong time, (which would be a broken flywheel key).

Will do as soon as I get off! and i Pulled the flywheel and inspected the key, which was whole. I will post Those pics after work thank you.

 

[JG122017]

Valve lash was set when both springs fully relaxed. TDC of compression stroke (not on the bump for compression release, not TDC of exhaust stroke)?

EDIT : I think if the crank and cam dots were aligned when setting lash, that means you were close to TDC on compression stroke. So just make sure lash wasn’t set on the bump for compression release.

if you watch the valves move while turning the engine over by hand… you can see a small movement of the exhaust valve after the intake valve closes. This is the compression release. Turn the engine past this bump, then set lash.

This may be it!!! I will reverify valve lash under those conditions and see if that helps thank you!

 

[bob58o]

This may be it!!! I will reverify valve lash under those conditions and see if that helps thank you!

And as Denny said, 0.005” is more than I use for lash. When engine is cold, I usually try for 0.001 or 0.002”.

On these engines, lash grows as engines heat up. Some people try for zero lash when cold to get maximum lift from the cam.

 

[Whitetrashrocker]

Leaving some lash, is retarding the cam, and lowers the torque curve. It's minute though. Too much makes a noisy valve train.

 

[JG122017]

Update** I had apparently lashed the valves on the bump for compression release. after lashing them TDC of compression stroke brought it to life immediately. thank you all for the help getting it back going.

However as always you fix one gremlin and it just makes another poke his head out. I was extremely careful when pulling the torque converter in an attempt for it to slide right back on after the motor was finished but now when I attempt to pull start it the belt grabs the rear pulley and acts as if it’s in “drive“ so to speak.


Tomorrow is another day though if anyone has any insight I appreciate it I don’t want to clutter up a bunch of threads with issues on the same kart

 

[bob58o]

Update** I had apparently lashed the valves on the bump for compression release. after lashing them TDC of compression stroke brought it to life immediately. thank you all for the help getting it back going.

However as always you fix one gremlin and it just makes another poke his head out. I was extremely careful when pulling the torque converter in an attempt for it to slide right back on after the motor was finished but now when I attempt to pull start it the belt grabs the rear pulley and acts as if it’s in “drive“ so to speak.


Tomorrow is another day though if anyone has any insight I appreciate it I don’t want to clutter up a bunch of threads with issues on the same kart

Show some photos of TC and belt set up.
Belt Alignment and stuff.
Show the driven unit and how the points and plastic buttons sit when engine is off.

 

[JG122017]

Show some photos of TC and belt set up.
Belt Alignment and stuff.
Show the driven unit and how the points and plastic buttons sit when engine is off.

Here is the setup

 

[Whitetrashrocker]

You driver unit looks to be in the expanded side of things. I think the sheave is supposed to fit more inside the shell.

 

[bob58o]

Maybe a TorqueyVerter tear down would be worth it. Inspect the springs and things in the DriveR Unit. The DruveN unit might need a scrubbing/cleaning. Looks like it’s rusty on top and caked in belt down lower.

The DriveR unit should be “all the way closed” when just sitting there.

 

[bob58o]

Bronze bushing should sit between the sheaves… Belt rides on it and helps it slip.

Not sure if being used as a spacer now, but maybe try something else as a spacer. I wear through those bushings quite a bit.

 

[JG122017]

Awesome thank yall. as for the bronze bushing that’s what I thought as well but when I disassembled it was where I have it theres 2 actual spacers that it was slid over

 

[JG122017]

And once again you all are on the money I pulled the torque converter and low and behold somehow the springs allowed the inner piece to come apart enough for the “guide rods” to fully come out of their holes thus making it stick open