Mildly Built Predator 212 Non Hemi Surging at WOT

[BrownStainRacing]

Bigger jet bigger problem only at WOT…..
hints of fuel delivery problems.
float level?
fuel line size?
debris in needle/seat?
pinched fuel line?
vacuum leak?
crap carb?

That's right,... they have different size needle and seats also.

Very well could be running out of fuel.

 

[JSleez]

No, no,......ground strap on plug is what I need to see.

Lol. My bad. Here are some photos. Spark plug has the threaded portion on it and I’m unsure if I need the adapter for it. Clicks on fine without it. Also added a photo of the old stock coil.

 

[BrownStainRacing]

Lol. My bad. Here are some photos. Spark plug has the threaded portion on it and I’m unsure if I need the adapter for it. Clicks on fine without it. Also added a photo of the old stock coil.

Here's your plug ground strap. I was looking where the change of color is happening on the strap.

I think @Master Hack is on to something about fuel delivery.

that clamp you have on the fuel hose, is that closing the hose up???

 

[JSleez]

Whoops. Here you go.

also attached my fuel delivery setup. It’s no clean and there are definitely some restrictions/losses along the way. The problem is the barb on the cheap fuel tank is too large to run the same diameter hose throughout. Have to think of a way to do that. Possibly hose clamp the larger diameter hose onto the carb. Or just have a very small piece of that tubing on the nipple on the carb as a thickener almost.

 

[Master Hack]

improve the fuel line and add a fuel filter. You can buy cheap filters that acomodate two different hose sizes, so you can have one size going in and a different size going out. That way you can change size neatly.
use the biggest size line that will actually fit properly.
lf that is just cheap vinyl hose, that is dangerous. Even fuel rated plastic hose can melt. Rubber hose is much better.

 

[BrownStainRacing]

I've seen a "seat to jet flow chart" somewhere years ago. I cant seem to find it online now.

But it was interesting how different size seats are needed for jets, psi, gravity feed, # of cylinders, size of engines.....you know all that useless info we never think about.

Bigger jet bigger problem only at WOT…..
hints of fuel delivery problems.
float level?
fuel line size?
debris in needle/seat?
pinched fuel line?
vacuum leak?
crap carb?

 

[JSleez]

I've seen a "seat to jet flow chart" somewhere years ago. I cant seem to find it online now.

But it was interesting how different size seats are needed for jets, psi, gravity feed, # of cylinders, size of engines.....you know all that useless info we never think about.

So I took apart my carb, cleaned everything. Made sure it was aligned right with my intake runner.
I also adjusted the float to be 1inch above the flange.
also changed to all 1/4” rubber line throughout with a filter in between.

This seemed to fix the issue when I had the 130 jet in, I would only have the cut at the very end of the rpm range.
Until I pulled my plug and saw it was super lean.

I threw in a 140 jet. And the issue just got worse. Cutting at WOT and no power, however the plug looked so much better, golden brown. I think my issue is the float? Seems like the only logical explanation.

 

[JSleez]

I think carb might just be junk. Moved the float back to how it came from the factory. Put the 130 jet in with a new plug.
I got one decent pull then it just starts cutting again.

y’all have a recommendation for a carb? Was thinking a 24mm Nibbi? Don’t want to kill my pockets.

 

[BrownStainRacing]

I think carb might just be junk. Moved the float back to how it came from the factory. Put the 130 jet in with a new plug.
I got one decent pull then it just starts cutting again.

y’all have a recommendation for a carb? Was thinking a 24mm Nibbi? Don’t want to kill my pockets.

I stopped using slide carbs on these small blocks.
Too much hassle, filters get knocked off, intakes come loose or get crack.

I've been using bored SA (stock apperaing) carbs. They work, nasty hole shots, pulls hard off the line all thur the whole rpm range. Throttle response is there instantly.

I've been using this .675" SA carb from racersproquip for about a yr now on my 224 with stock air box and filter, i'll never go back to a slide carb.

Dover Power is "king" of SA carbs with their "Holy Moses" program, imho. They are nasty, nasty lil boogers.

Warning: they got to idle 2000+ rpm, so a cheap 2200 rpm clutch WILL NOT work.

The low speed circuits are reworked, that's what makes them so snappy happy.

Kart Racing "Stock Appearing" BIG FLOW & Bore Carburetor #675 w/Jet Kit USA NEW | eBay

Carburetor is ready for your custom engine build. Will fit all Predator Hemi and non Hemi engines and Honda GX200, BSP yellow, Greyhound, Central Machinery, and equivalent 196cc 208cc 212cc 218cc type clone engines.

www.ebay.com

Clone / Predator Outlaw Carb (Kart Racing)

www.doverpoweronlinestore.com

 

[JSleez]

I stopped using slide carbs on these small blocks.
Too much hassle, filters get knocked off, intakes come loose or get crack.

I've been using bored SA (stock apperaing) carbs. They work, nasty hole shots, pulls hard off the line all thur the whole rpm range. Throttle response is there instantly.

I've been using this .675" SA carb from racersproquip for about a yr now on my 224 with stock air box and filter, i'll never go back to a slide carb.

Dover Power is "king" of SA carbs with their "Holy Moses" program, imho. They are nasty, nasty lil boogers.

Warning: they got to idle 2000+ rpm, so a cheap 2200 rpm clutch WILL NOT work.

The low speed circuits are reworked, that's what makes them so snappy happy.

Kart Racing "Stock Appearing" BIG FLOW & Bore Carburetor #675 w/Jet Kit USA NEW | eBay

Carburetor is ready for your custom engine build. Will fit all Predator Hemi and non Hemi engines and Honda GX200, BSP yellow, Greyhound, Central Machinery, and equivalent 196cc 208cc 212cc 218cc type clone engines.

www.ebay.com

Clone / Predator Outlaw Carb (Kart Racing)

www.doverpoweronlinestore.com

Those carbs seem much more reliable.

do they make similar power?

I don’t know if I could go back to the stock linkage setup. It always felt so poor compared to the slide carb “linkage”

 

[BrownStainRacing]

Those carbs seem much more reliable.

do they make similar power?

I don’t know if I could go back to the stock linkage setup. It always felt so poor compared to the slide carb “linkage”

More then most will ever need.

They make really good top throttle plates, I get 3/4 turn outta my grip. Stock throttle assembly only gets about a 1/4 turn.

The red engine is a governored ducar 212 with a .615" ARC SA carb.

These are not small tire, big geared mini bikes, the ducar has 4.54:1 gear, the black engine (224) has 4.6:1 gear and both have 20" tires.
It takes a lil power to turn those gears and big tires like that. I don't do that on hard pack surfaces.

 

[JSleez]

More then most will ever need.

They make really good top throttle plates, I get 3/4 turn outta my grip. Stock throttle assembly only gets about a 1/4 turn.

The red engine is a governored ducar 212 with a .615" ARC SA carb.

These are not small tire, big geared mini bikes, the ducar has 4.54:1 gear, the black engine (224) has 4.6:1 gear and both have 20" tires.
It takes a lil power to turn those gears and big tires like that. I don't do that on hard pack surfaces.

Badass bikes. Probably tons of funs out in the woods.

You know where I can find those top throttle plates?

 

[BrownStainRacing]

Badass bikes. Probably tons of funs out in the woods.

You know where I can find those top throttle plates?

I think everybody sells them. I can't remember where I got mine.
Mine as different settings for the grip. If you zoom in, you might beabkle to see the different holes for the rod. It can be set for 1/4, 1/2, or 3/4 twist.
I'll see if I can find it.

 

[BrownStainRacing]

Badass bikes. Probably tons of funs out in the woods.

You know where I can find those top throttle plates?

You have the non hemi pred block. It has different tank mounts then the hemi and other clones style block. It's gonna need a different plate. I cant think who makes them, but I keep looking.

 

[BrownStainRacing]

Here ya go.
Dover has 1, looks good. Has ram-air,

I don't know about the ram-air, but looks cool.

Ram Air Top Plate Std & Kits

www.doverpoweronlinestore.com

 

[JSleez]

So I swapped out the Chinese Mikuni for a 24mm Nibbi. Put a 52 pilot and 125 main in there, it runs great but the plug was two toned. I jumped up to a 135 main and still two toned.
Any suggestions?

also the piston isn’t dirty at all, I just had the light on my borescope all the way down lol.