Predator 212 wont fully start

[BrownStainRacing]

@LtDansNewLegs
Before you put your order in, check crank end play. I set em at .010". Every pred I've seen, needed the crank shimmed. It keeps the crank from beating the sides of the rod, and every things stays nice and straight.
Little things like this helps the upper rpm range.

I shim the cam too, but you gotta pull the crank and use hole in side cover to measure cam end play.

Crank shim kits are usally 4-$5.

 

[LtDansNewLegs]

What direction should the check valve be for the fuel tank breather? I thought it was supposed to point in but the stock valve check has an arrow pointing out. Thanks

 

[G.W]

Has anyone tried PWK carbs? Made by Keihin. I got one for a project just cuz it was cheap. I was so surprised and impressed that l put one on franken buggy. Ebay has ‘em in 20-40mm sizes.
first thing l think of when a carb change doesnt work out is, a vacuum leak. The plug reading may say different, but is it the same plug that was in when it ram?

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I know they work good on high performance motorized bicycle engines, but I've never used one on a go kart

 

[BrownStainRacing]

Arrow out to atmosphere.

Blow thur it to make sure which direction it goes.

I trust.... NOTHING

 

[BrownStainRacing]

What direction should the check valve be for the fuel tank breather? I thought it was supposed to point in but the stock valve check has an arrow pointing out. Thanks

Wait a min. I jus seen you said "fuel tank" .

Fuel tank needs to vent so fuel will flow.
A "check valve" is not gonna work. It's stays closed til it has pressure under it.

You jus need to "vent" the tank.

It should have a safety valve ( a ball or BB) in it that will close incase a roll over.

 

[LtDansNewLegs]

Copy on the no check valve for the tank breather. Question about the valve cover breather though…
Now that I have the crankcase venting to the valve cover with a new outlet drilled in the middle between the two rocker arms, I’m seeing oil leak out of the stock valve breather hose due to the crankcase vent bringing oil up with it. What do you suggest to stop that? Just wrap tape around the valve breather hose to make it a tighter fit?

 

[BrownStainRacing]

Copy on the no check valve for the tank breather. Question about the valve cover breather though…
Now that I have the crankcase venting to the valve cover with a new outlet drilled in the middle between the two rocker arms, I’m seeing oil leak out of the stock valve breather hose due to the crankcase vent bringing oil up with it. What do you suggest to stop that? Just wrap tape around the valve breather hose to make it a tighter fit?

Get the check valves up away from the valve cover. The farther the better. Keep check valves above the valve cover. A small filter on each check valve will help keep dirt out.

You are using 2) check valves, right???

Get a farther away pic so I can see everything.

 

[BrownStainRacing]

Copy on the no check valve for the tank breather. Question about the valve cover breather though…
Now that I have the crankcase venting to the valve cover with a new outlet drilled in the middle between the two rocker arms, I’m seeing oil leak out of the stock valve breather hose due to the crankcase vent bringing oil up with it. What do you suggest to stop that? Just wrap tape around the valve breather hose to make it a tighter fit?

Crankcase Recirculation on aftermarket intake

I've got a GX200 (196cc clone) with many upgrades, among those are an aftermarket airfilter. I was wondering if I could connect the breather hose from the crankcase breather and thread a nipple into the air filter to 'recirculate' the air that comes out of the breather. I am aware that among the...

www.diygokarts.com

 

[LtDansNewLegs]

Get the check valves up away from the valve cover. The farther the better. Keep check valves above the valve cover. A small filter on each check valve will help keep dirt out.

You are using 2) check valves, right???

Get a farther away pic so I can see everything.

Get the check valves up away from the valve cover. The farther the better. Keep check valves above the valve cover. A small filter on each check valve will help keep dirt out.

You are using 2) check valves, right???

Get a farther away pic so I can see everything.

Only one check valve in the valve breather at the moment.

 

[BrownStainRacing]

Only one check valve in the valve breather at the moment.

OK. That's the problem.
When the piston is on it way up, it's pulling in air thur the hose that does not have a check valve. This puts pressure under the piston when it comes back down.

Plug 1 hose, with whatever it takes and keep the other with the check valve up high and away from the valve cover.

 

[LtDansNewLegs]

OK. That's the problem.
When the piston is on it way up, it's pulling in air thur the hose that does not have a check valve. This puts pressure under the piston when it comes back down.

Plug 1 hose, with whatever it takes and keep the other with the check valve up high and away from the valve cover.

What do you mean by plug the hose? My setup is based off this one minute video minus the fact that I only have one crankcase vent hose vs the two in the video. He wasn’t using check valves for the crankcase hoses. Is that what you’re saying is the problem?

 

[BrownStainRacing]

Only one check valve in the valve breather at the moment.

Looks like you have room to run the hose, in the middle, up over you tank. Use zip ties, loosely to hold it to the tank vent hose. Let it lay over on the front side of engine with the check valve and filter.
If oil should get that far it won't stop the valve from working, if it's pointing down toward the ground with the filter attached to it.

In 1 of those pics, you will see how I got the check vakve laying almost flat, jus incase oil gets there.

But there's never any oil there.

 

[BrownStainRacing]

What do you mean by plug the hose? My setup is based off this one minute video minus the fact that I only have one crankcase vent hose vs the two in the video. He wasn’t using check valves for the crankcase hoses. Is that what you’re saying is the problem?

That's why I needed to see every thing.

He has the hose coming from the side cover to valve cover so more oil will get slung to the valves.

This is total bs. Theres more then enough oil coming from the other side of the head and between the lifters then is needed. I tried this, it is not necessary. Pull your valve cover off and start it up, you will see.

I'd rather have less pressure under my piston, using 2 check valves, then have more unnecessary oil in the valve cover. But, that's me.

Put a vacuum/pressure gauge on it, you will see.

 

[LtDansNewLegs]

That's why I needed to see every thing.

He has the hose coming from the side cover to valve cover so more oil will get slung to the valves.

This is total bs. Theres more then enough oil coming from the other side of the head and between the lifters then is needed. I tried this, it is not necessary. Pull your valve cover off and start it up, you will see.

I'd rather have less pressure under my piston, using 2 check valves, then have more unnecessary oil in the valve cover. But, that's me.

Put a vacuum/pressure gauge on it, you will see.

Got it. But where are you saying I need to put the second check valve? In the crankcase hose or drill another valve breather?

 

[BrownStainRacing]

Got it. But where are you saying I need to put the second check valve? In the crankcase hose or drill another valve breather?

Look at mine. Both outta the valve cover, will have less oil slung up in to them. Pressure out, no air in.

Since you only have 1 check valve, then you only need 1 hose.

2, ALWAYS showed less crankcase pressure on the gauge.
3 and 4 check valves showed no difference at high rpm. They might, if the engine was worn out more.

Did you drill into your side cover????

I'd say that's why you are seeing oil coming out the original vent hose. Jus too much oil up top.

I don't use the side cover ports because the crank and cam gears are oil slinging fools, . Yes, I tried them.
Notice the billet side cover with 2 ports???? That 1 hose goes to the vacuum/ pressure gauge, not to the valve cover.

 

[LtDansNewLegs]

Nice for me that you already tested the number of breathers/check valves and seems like 2 is the sweet spot! LOL

The crankcase hose I installed is coming from the hole where the governor arm was. A new vented side cover was too expensive in my mind so I did it myself.

 

[BrownStainRacing]

Nice for me that you already tested the number of breathers/check valves and seems like 2 is the sweet spot! LOL

The crankcase hose I installed is coming from the hole where the governor arm was. A new center side cover was too expensive in my mind so I did it myself.

OK. That's a better port then the side cover, you will get oil slinging, but not as much as the side cover. I would jus plug it, plug the hose outta valve cover for now, til you get another check valve. Then use the 1 valve you have, and run it like I mentioned earlier.

Yea, I done a lot of testing this.
I started testing when the high reving clutch guys were having problems with blown gaskets, seals and side cover bolts coming loose.
The problem, was too much crankcase pressure.

I had 1 of their engines on the stand, after a new piston and ring install, and jus couldn't understand why so much pressure on the gauge. Walked up to my truck and stole the brake booster check valve off it, put it in the valve cover and the pressure dropped in half.
Went down the road to junk yard, picked up 4 or 5 more, for testing. 2 worked better then 1,

Problem solved.