csc tt250 catalytic converter help

[Choco]

Hi everyone,
Im new here i just bought my first bike and i love this thing.
I wanted the white color, but did not want to wait 2 months for a bike so orange it is. its honestly not bad at all.
I wanted to gut the cat out to get some more power out of this bike. Anyone know where the exact location is? i don't want to cut the wrong location. i been looking at other setups people done, but i like the all black exhaust to be honest. I have the jets coming in by this weekend and i wanted to get it all done together.

Thank you for your help.
Any china riders from the bay area around?

[Weldangrind]

Do you see a bulge in the header pipe, just a few inches from the head?

[Choco]

Originally Posted by Weldangrind

Do you see a bulge in the header pipe, just a few inches from the head?

Right behind the heatshield looking piece?

[TheChairman]

The TT250 muffler is hollow with packing and no spark arrestor. At the "back" of the muffler, you will find a cat converter that looks strikingly similar to those round corrugated cardboard cat cons you see for sale in the Wish ads on Facebook. Behind that is a baffle.

The majority of the restriction in the factory exhaust is going to be at the end cap to the muffler can.

Remove the 3 hex head screws and remove the end cap. Use a hacksaw and cut off the "nipple" at the end of the exhaust can as close to the can as possible. Then take a 1 1/2 inch metal hole saw and center it on the exhaust hole in the can. Cut your hole. Reinstall the end cap and the three hex head bolts. Use some sort of Loctite on the threads or they will rattle loose. This will maintain your clean, factory look.

I would recommend leaving the cat and baffle behind it in place. The increase in sound and flow will be significant enough. For more sound and flow, remove the snorkel on the airbox. Its only glued in place, and can be easily returned using silicone if you ever decide to do so.

You will absolutely need to rejet and retune your carburetor after doing this. Order a jet kit before you begin.

Don't do any of these things until the bike is completely broken in and out of warranty. In fact, don't do them at all.

[Choco]

Originally Posted by TheChairman

The TT250 muffler is hollow with packing and no spark arrestor. At the "back" of the muffler, you will find a cat converter that looks strikingly similar to those round corrugated cardboard cat cons you see for sale in the Wish ads on Facebook. Behind that is a baffle.

The majority of the restriction in the factory exhaust is going to be at the end cap to the muffler can.

Remove the 3 hex head screws and remove the end cap. Use a hacksaw and cut off the "nipple" at the end of the exhaust can as close to the can as possible. Then take a 1 1/2 inch metal hole saw and center it on the exhaust hole in the can. Cut your hole. Reinstall the end cap and the three hex head bolts. Use some sort of Loctite on the threads or they will rattle loose. This will maintain your clean, factory look.

I would recommend leaving the cat and baffle behind it in place. The increase in sound and flow will be significant enough. For more sound and flow, remove the snorkel on the airbox. Its only glued in place, and can be easily returned using silicone if you ever decide to do so.

You will absolutely need to rejet and retune your carburetor after doing this. Order a jet kit before you begin.

Don't do any of these things until the bike is completely broken in and out of warranty. In fact, don't do them at all.

I will play around with it this weekend. My jets are now supposed to arrive today. so i will see how it goes.
Yea ofcourse after warranty lol.

[Choco]

I couldn't wait to replace the jets. I installed a 110 and drilled a slot to the mixture screw. I put it to 2 1/2 turns(it was at 2 turns) ooo maaaannnn what a difference this makes. I still want to mod the exhaust hopefully i get to play with it this Sunday

[Choco]

Quick update,
I put in my inspection camera through the exhaust.
I found the cat inside the actual exhaust. For my luck it is welded from both ends so i had to cut at the back of the exhaust,then cut the middle pipe with a sawzall and cut the cat out. Check out the pics. Tomorrow i will weld it back up, paint it, put it back on and see if there is any difference.
I figured i will post it since i didnt find anyone with a csc tt250 that has done it.

[Choco]

Pictures of the cat from both ends with my inspection camera

[Choco]

I welded up the exhaust painted it with high heat ceramic coating paint(looks like nothing happened)
Its definitely louder. Difference i can tell just abit not alot,but enough to notice. I will try a 115 jet to see how that feels once i run it abit more. If you ask me if it was worth it. Well each person has their opinion but to me it was worth it

[TheChairman]

The pilot jet that comes with the jet kit is too big if you remove the evap canister from the system. Its sized to include the large vacuum leak the canister causes.

If you remove the canister, stick with the factory pilot jet and install the new adjustment screw and parts.

I am going up to a 115 on the main jet. The 110 seems a bit small for this exhaust mod.

[Choco]

Originally Posted by TheChairman

The pilot jet that comes with the jet kit is too big if you remove the evap canister from the system. Its sized to include the large vacuum leak the canister causes.

If you remove the canister, stick with the factory pilot jet and install the new adjustment screw and parts.

I am going up to a 115 on the main jet. The 110 seems a bit small for this exhaust mod.

Sorry for being a noob here but i kind of got lost on what you are trying to tell me.
If i get rid of the canister it will eliminate a vacuum leak it comes with? Is that what makes the popping sound I'm guessing?
This is the kit i bought.
https://www.amazon.com/Wingsmoto-Mik.../dp/B017SJO94S
I will swap the main jet to a 115 in the next 2 days and see how that feels. Do you have the same bike? If so what other mods do you have?

[Choco]

Originally Posted by TheChairman

The pilot jet that comes with the jet kit is too big if you remove the evap canister from the system. Its sized to include the large vacuum leak the canister causes.

If you remove the canister, stick with the factory pilot jet and install the new adjustment screw and parts.

I am going up to a 115 on the main jet. The 110 seems a bit small for this exhaust mod.

If i leave the canister alone no harm or difference correct? i think if it will not male any difference i will just leave it alone

[TheChairman]

The canister represents a vacuum leak. It hooks up between the tank and the carburetor. Vacuum pulls fumes from the tank through the canister and into the carburetor.

When you eliminate it, it will enrichen the overall fuel mixture. Mostly at idle as the vacuum port on the carburetor is somewhat small.

[Choco]

Originally Posted by TheChairman

The canister represents a vacuum leak. It hooks up between the tank and the carburetor. Vacuum pulls fumes from the tank through the canister and into the carburetor.

When you eliminate it, it will enrichen the overall fuel mixture. Mostly at idle as the vacuum port on the carburetor is somewhat small.

I will be removing it one of these days

[Airhead]

Originally Posted by TheChairman

The canister represents a vacuum leak. It hooks up between the tank and the carburetor. Vacuum pulls fumes from the tank through the canister and into the carburetor.

When you eliminate it, it will enrichen the overall fuel mixture. Mostly at idle as the vacuum port on the carburetor is somewhat small.

Anyone else experience this effect from removing the canister and plugging the carb nipple? I understand the theory but doubt it would be noticeable or that you would have to compensate for it. I've never had a problem with removing this and the EGR ugly appendages.