Apollo 250 SMOG/Emissions Control Delete

[ben2go]

The smog system on motorcycles are nothing but air injection systems that injects air into the exhaust stream, just past the exhaust port. It fools the emissions test into thinking the engine is running cleaner than it actually is.

[pete]

Originally Posted by ben2go

The smog system on motorcycles are nothing but air injection systems that injects air into the exhaust stream, just past the exhaust port. It fools the emissions test into thinking the engine is running cleaner than it actually is.

theres a little bit more to it than that.... the air/O2 lets the cat burn any unburnt
fuel that enters the pipe....
ever wondered why a big single pops / bangs & back fire out the pipe while
coasting on a trailing/closed throttle..
Red hot cat / unburnt fuel & O2 .. it all adds up to bang... burnt in the pipe
not coming out the back..

wait till yer see what coming.... Euro4 for bikes comes in this year in europe..
one of the driving forces behind all these 2 cyclinder ADV bikes..
it's easyer to deal with 2 smaller charges of exhaust gases with the limited
space a bike has that one big charge like from a big single...
Euro4 is the sole reason Yamaha has stoped production of the 660cc single
and is bringing out a 700cc twin cyclinder Tenere... uses the MT07 motor..



..

[ben2go]

Originally Posted by pete

theres a little bit more to it than that.... the air/O2 lets the cat burn any unburnt
fuel that enters the pipe....
ever wondered why a big single pops / bangs & back fire out the pipe while
coasting on a trailing/closed throttle..
Red hot cat / unburnt fuel & O2 .. it all adds up to bang... burnt in the pipe
not coming out the back..

wait till yer see what coming.... Euro4 for bikes comes in this year in europe..
one of the driving forces behind all these 2 cyclinder ADV bikes..
it's easyer to deal with 2 smaller charges of exhaust gases with the limited
space a bike has that one big charge like from a big single...
Euro4 is the sole reason Yamaha has stoped production of the 660cc single
and is bringing out a 700cc twin cyclinder Tenere... uses the MT07 motor..



..

I simplified it a little.

[2LZ]

That's why it's a good thing to disable the air injection unit if you delete the cat or change your pipe. That shot of O2 that's supposed to get tossed on the cat like a blow dryer on a briquette, now can blast your muffler packing on the way out.

[apolloman]

Originally Posted by MudIntent

This past weekend. I made some more changes to the apollo, I wanted to get the pictures up in case anyone was interested. Here is a list of what I did.

* Removed Cat from header pipe. I didn't really care to make it look pretty so I used the tried and true method of cutting the pipe in half right before the bulge and drilled and chiseled it out. This took longer than I initially anticipated, that sucker was glued in with some pretty strong adhesive. As you can see in the pics, it had to be restricting at least 50% of the exhaust air flow. I then had it welded back together using the heat shield installed to keep it lined up.

* Removed all of the Smog crap that I later found out was called the SAIS (secondary air injection system) cali / EPA crap. Cut the head vent off and had a buddy weld the hole shut into a plate as Slayder described doing with his.

* I ended up removing the stock oil/air separator (I think that's what it's called) that's connected to the crankcase vent. I plan on either running a new hose with a K&N vent filter on the end out of the way somewhere, replacing the stock setup or just running a new hose straight towards the ground but I worry about debris getting sucked in with that method... and thoughts?

The next move will be re-gearing it and replacing the stock chain with one that's a little beefier. Mine came stock with a 14 Tooth front Sprocket and a 38 Tooth in the rear. Nowhere near the low end power that I want and plenty of top end speed so I know I can sacrifice a good bit of that for low end grunt. I have already acquired a new chain and 12 Tooth front Sprocket and am waiting on a custom rear Sprocket that I ordered from Kim with PMP sprockets in Texas. I had a hell of a time trying to find a rear sprocket that had more than one measurement the same as my stock rear Sprocket in 530 pitch, let alone a 48 Tooth. I ended up taking the measurements of mine and ordering a custom one. It was a little more than I was hoping to spend on a single sprocket for this bike but I'm hoping it works and gives me the power characteristics that I desire.

did u have any issues after u removes the smog stuff. I'm getting alot of popping from the exhaust. wants to staul out until it's totally warmed. I played with the idle screw but it just doesn't run as smooth as it did with the smog stuff on it

[ben2go]

Originally Posted by apolloman

did u have any issues after u removes the smog stuff. I'm getting alot of popping from the exhaust. wants to staul out until it's totally warmed. I played with the idle screw but it just doesn't run as smooth as it did with the smog stuff on it

The air injection system (smog crap) won't cause a stall unless there's a vacuum leak to it. It will cause exhaust popping. It injects fresh air into the exhaust just past the exhaust valve. Always check the valve clearances on these bikes when you get them. They're almost always too tight and can cause running issues. You may need to clean the carb if you've been riding a lot and install a fuel filter. make sure the fuel filter is rated for gravity flow. Also, the idle on these bikes should be between 1200 and 1500 rpm. I know there's not a tachometer on most China bikes, so it has to be done by ear, or add a tach on. Even thought the factory carb and jetting is complete crap, it should still run ok. The bike just won't provide maximum power.