Troubleshooting Predator 212

[devlinrules12]

Hey new to the forums so sorry if i post this in the wrong section. I am having troubling with my modified predator 212 non hemi. I can not get it to run correctly.
My mod list is :
Gov removed
18lb springs
1.3 ratio rockers
7 degree timing key
0.10 head gasket
billet rod/flywheel
vm22 chikuni carb with 125 jet
trumpet exhaust
Now the problem I keep having is I can not get the engine to run without the choke and i have a loss of power. The engine dies immediately if I turn the choke off. Now I can sometimes get it to run with the choke off if I play with the throttle but as soon as I rev to full throttle it dies . I have tried adjusting the idle and air/fuel mixture screw that does not help, I have also checked valve lash maybe 5 times now, I have also uninstalled/reinstalled carb multiple times just to make sure the o ring is lined up with the intake evenly. I even sprayed carb cleaner around the intake to see if the idle changes and it does not. Do you guys maybe have any tips or suggestions to point me in the right direction

 

[River Rat Ron]

Main jet plugged likely
Needle valve / float sticking less likely


Pull carb, dis assemble clean well with carb cleaner and clear passages with a blowgun
I first try a tip cleaner to clear a plugged main jet.
Often they can be un cooperative to remove plus you can screw one up rather easily as they are soft brass

 

[devlinrules12]

Ok will pull carb and give it a good cleaning and let you know what happens thanks for the speedy reply.
Also while I am in there how can I check if the needle valve/float is sticking?

 

[River Rat Ron]

Ok will pull carb and give it a good cleaning and let you know what happens thanks for the speedy reply.
Also while I am in there how can I check if the needle valve/float is sticking?

after removing the float bowl the float should be hanging, if holding carb in its normal orientation of operation.
The needle valve is attached to it. Just move it up and down to see that it’s free. This is usually not the problem you describe….it’s the main jet
Be careful removing the bowl so you can re use the gasket .

 

[devlinrules12]

after removing the float bowl the float should be hanging. The needle valve is attached to it. Just move it up and down to see that it’s free. This is usually not the problem you describe….it’s the main jet
Be careful removing the bowl so you can re use the gasket .

ok will do thanks again pulling carb as we speak hopefully this fixes it ive been fighting this bike all weekend

 

[River Rat Ron]

Side note : This is common in a motor that has set awhile with untreated fuel in it. Obviously not in this case.
Often times the fuel in the bowl evaporates and leaves the additives that are in the fuel.
Once you put fuel into the carb again these additives don’t dissolve, they break up and start clogging up your carb.
In the old days we ran the engine dry before storing. Now I only use a fuel stabilizer and have never had a problem
Also use an inline fuel filter between tank and carb and keep your gas can fill spout capped.
Wipe out a funnel before using.

 

[devlinrules12]

Side note : This is common in a motor that has set awhile with untreated fuel in it. Obviously not in this case.
Often times the fuel in the bowl evaporates and leaves the additives that are in the fuel.
Once you put fuel into the carb again these additives don’t dissolve, they break up and start clogging up your carb.
In the old days we ran the engine dry before storing. Now I only use a fuel stabilizer and have never had a problem
Also use an inline fuel filter between tank and carb and keep your gas can fill spout capped.
Wipe out a funnel before using.

ok so i cleaned carb and made sure float was not stuck still having the same issue

 

[Minimichael]

Check the lash again

 

[River Rat Ron]

That 22 mm slide carb is a bit of a different story. I would have still suggested cleaning it. In my old MX days the slide carbs has a small c clip on the center metering rod. It adjusted up and down to meter fuel to the motor.

 

[devlinrules12]

That 22 mm slide carb is a bit of a different story. I would have still suggested cleaning it. In my old MX days the slide carbs has a small c clip on the center metering rod. It adjusted up and down to meter fuel to the motor.

i have the small c clip in the middle notch and will check valve lash one more time

 

[Minimichael]

That 22 mm slide carb is a bit of a different story. I would have still suggested cleaning it. In my old MX days the slide carbs has a small c clip on the center metering rod. It adjusted up and down to meter fuel to the motor.

So you think he should clean his metering rod? I don't see it ever being wet enough, with the bowl being dry and in storage anyways.

 

[devlinrules12]

Check the lash again

checked valve lash again it is correct at .003

 

[SAS289]

Does your carb have an o ring on the intake side? If you have an air leak you'll never tune your way out of it. Bolt the carb to the intake first aligning the carb to the intake, then bolt the assembly to the head.

 

[devlinrules12]

Does your carb have an o ring on the intake side? If you have an air leak you'll never tune your way out of it. Bolt the carb to the intake first aligning the carb to the intake, then bolt the assembly to the head.

yes it has an o ring ive realigned it multiple times off of the head. I also sprayed carb cleaner around intake to see if the idle would change and it did not. But I will take it off and try again

 

[River Rat Ron]

So you think he should clean his metering rod? I don't see it ever being wet enough, with the bowl being dry and in storage anyways.

Not that as much as the carb body, galleys etc…

 

[River Rat Ron]

i have the small c clip in the middle notch and will check valve lash one more time

That’s where it should be normally. Move it up a notch to richen. Are you sure the gas cap is venting, fuel line flowing.
I’ve fixed a number of small engines with a dead spider in the tank blocking the fuel line outlet. How do they get in there? They crawl into your gas can via the long un capped spout and get high n die fall in the gas…crazy I know, but true.

 

[devlinrules12]

I have a clear fuel line and fuel filter that I can see the gas going into the carb . I am at work right now but when I get back home I’ll move the clip and double check that the o ring is seated evenly to the intake again

 

[panchothedog]

I doubt that this is your immediate problem, but who knows. You stated billit rod and flywheel. If it is a typical ARC flywheel it comes with 32 degrees of advance built into it. By adding a 7 degree key you are at 39 degrees. WAY
to much. You are still at standard compression ratio, and aside from the ratio rockers ( more lift ) your cam is stock duration. Your engine will run as strong as it possibly can with 32 degrees of advance. Remove the flywheel, install the stock straight up key, and go from there.

 

[devlinrules12]

I doubt that this is your immediate problem, but who knows. You stated billit rod and flywheel. If it is a typical ARC flywheel it comes with 32 degrees of advance built into it. By adding a 7 degree key you are at 39 degrees. WAY
to much. You are still at standard compression ratio, and aside from the ratio rockers ( more lift ) your cam is stock duration. Your engine will run as strong as it possibly can with 32 degrees of advance. Remove the flywheel, install the stock straight up key, and go from there.

Will also try this when I get home and report back to you guys

 

[devlinrules12]

Ok so I think I found my issue. The 7 degree timing key broke. Also my luck I lost the stock key..... so I ordered a couple and will update you guys once they get here in two days .