[MrKitty]

Most of my threads start out the same I'm going to be taking this brand new engine and modify it to do some performance oriented pocket bike riding...

I think I'll set the budget on this build at 60$ that will give me some wiggle room to buy some performance parts on this build if I want...

 

[MrKitty]

For the very first modification and the modification that should be first on any of these CAGs is the high fuel flow mod AKA the petcock delete mod on this one I'm going to be removing everything the rubber part and the white plastic knob and filling it with JB weld then drilling it out.

the petcock itself and the little rubber o-ring on the bottom are the only parts you need the rest are rubbish!

This will give it a nice clean look...

 

[Atvrunner2]

I have a new engine in storage. I should start to modify it. Cool thing is the squish as I received it was 0.047" good start there.

 

[MrKitty]

I have a new engine in storage. I should start to modify it. Cool thing is the squish as I received it was 0.047" good start there.

Sounds like a nice fresh canvas to start out with...

 

[MrKitty]

After the JB weld hardens go ahead and drill all the way through the petcock

Now there's no more worries about the petcock getting half turned off causing fuel starvation making the engine detonate and burn a hole through the piston

 

[MrKitty]

I took off the carby for modifications and can easily see tons of manufacturing debri this is why it's important to clean out the carburetor before you run one of these.

the metal shavings pictured is just what's inside the carburetor I'm sure there's more in the crankcase as well just waiting to score and scratch the brand new piston and cylinder...

After modification I will run the carburetor through my buddies ultrasonic cleaner this is not necessary and using carburetor cleaner to clean it out is sufficient to remove any metal debris

 

[Atvrunner2]

Anything else you are going to do to the carb??

 

[MrKitty]

I'm currently working on the enlarged float bowl mod I will also be doing the mass air flow / wide mouth mod and changing the lower needle angle

 

[Atvrunner2]

I'm currently working on the enlarged float bowl mod I will also be doing the mass air flow / wide mouth mod and changing the lower needle angle

Mass air flow??? This is not EFI. Lol
You mean the intake side of the carburetor I'm sure. One thing I have always done is drill out the path to the bowl from the petcock. Make it flow better. Because that is still another restriction as is the petcock.

 

[MrKitty]

Mass air flow??? This is not EFI. Lol
You mean the intake side of the carburetor I'm sure. One thing I have always done is drill out the path to the bowl from the petcock. Make it flow better. Because that is still another restriction as is the petcock.

100% definitely should be done as well

 

[MrKitty]

The Larger float bowl mod simply sand out the float bowl to make it larger.

The Max air flow mod I open up the mouth of the carburetor

Don't forget to drill down and open up the fuel inlet side just a tad.

adjust the float so that it fills the bowl to the maximum level hopefully not overflowing this adjustment may need to be changed later

Change the angle of the needle slightly and set it all the way up seems to work out the best...

 

[MrKitty]

When you open these engines up you can quickly see all the bad gasket matching that causes major restrictions

As I start to trim away at the gasket I see how bad it really is...

 

[Atvrunner2]

Oh, you got one of the bad needle jets. Almost straight as an arrow. Not the nice tapered ones.

 

[Atvrunner2]

The best thing about a brand new engine, it's the fact that it has brand new crank seals and bearings. Even though the bearings are the best. So much less to replace.

 

[MrKitty]

After modifying and flowing the Reed cage I also modified the shape of the Reed stop and change the angle slightly

 

[MrKitty]

Oh, you got one of the bad needle jets. Almost straight as an arrow. Not the nice tapered ones.

Yes it's going to kill my mid range throttle response ☹

 

[MrKitty]

The best thing about a brand new engine, it's the fact that it has brand new crank seals and bearings. Even though the bearings are the best. So much less to replace.

The bearings are actually okay as long as you never run them and clean out all the manufacturing debris before starting the engine...

 

[MrKitty]

After modifying the intake manifold...

 

[MrKitty]

I got another one where the fly wheel puller holes are not drilled or threaded makeing things a little more involved in getting apart.

You know the routine

Me and my helper have our fingers crossed...

 

[MrKitty]

Works every time tap a flat bar wedged in between the flywheel and crankcase not too tight or it will crack the crankcase.

Heat up the flywheel with a plumbing torch until the glue starts to smoke.

Give the flywheel bolt that's threaded a little bit out a whack with a hammer and the flywheel will pop right off.