Emissions testing and free mods


5 replies to this topic
  • ktmracing03

Posted December 27, 2011 - 11:13 PM

#1

I am new to the forum and new to 4 strokes. I have attempted to search for my answer so sorry if this has been beat to death but I need answers. I just got a 2003 WR450F which has had the air box mod, exhaust silencer removed, and grey wire mod done. As far as I know it is otherwise stock.

It is set up with new excel wheels and gold talon hubs and DOT tires. I installed a brake light switch and all the lights work. In AZ you do not need turn signals so it is set up to plate. The only problem I have now is the required emissions testing.

The bike passed the hydrocarbons but failed carbon dioxide emissions. My question is do the free mods have any effect on the emissions? If I hook the grey wire back up and put the silencer back in will the bike pass emissions?

The bike has been stored for the last 4 years according to the PO so I am in the process of taking the carb apart and cleaning everything really good as everything is all gummed up. In addition I have a new plug and air filter on the way. The bike runs strong so could it just be running rich?

Is there anything else I can do to make it pass?

  • 2grimjim

Posted December 28, 2011 - 08:04 AM

#2

The bike passed the hydrocarbons but failed carbon dioxide emissions.


I assume you mean carbon monoxide?

My question is do the free mods have any effect on the emissions?


Yes, they do.

The bike has been stored for the last 4 years according to the PO so I am in the process of taking the carb apart and cleaning everything really good as everything is all gummed up. In addition I have a new plug and air filter on the way.


Make sure every trace of old gas is removed from the fuel system.

The bike runs strong so could it just be running rich?


Elevated carbon monoxide is caused by a rich fuel mixture. You didn't specify the parameters of the test, i.e. how the test is performed. Knowing how the test is run and how far open the throttle was during the test will help with the jtting. The rich mixture can be caused by bad fuel, float level too high, or the jetting is off.

Is there anything else I can do to make it pass?


Yes, put a pint of ethanol in the tank before you fill it with gas if the gas you are buying doesn't already have 10% ethanol.

  • ktmracing03

Posted December 28, 2011 - 11:49 AM

#3

Thank you,

Yes I meant carbon monoxide. They did the test at idle and 1/4 throttle. Carbon monoxide idle standard is 5.5 and my bike gave a 9.86.

Should I reconnect the grey wire and put in the stock silencer to pass?

I got the bike and was concentrating on getting it set up for street use that I didn't even think about emissions.

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  • Sknight

Posted December 28, 2011 - 12:29 PM

#4

CO is strictly a rich condition. While cleaning the carb be sure to get one of the extended mixture screws so you can tune the idle easier. Depending on where in the test it failed you can greatly influence the CO number by leaning the idle mixture. It might not idle too well but if you get a pass then once you leave the station you can reset the mixture screw where it runs nice.

  • 2grimjim

Posted December 28, 2011 - 06:24 PM

#5

Depending on where in the test it failed you can greatly influence the CO number by leaning the idle mixture. It might not idle too well but if you get a pass then once you leave the station you can reset the mixture screw where it runs nice.


Leaning it out too much is a double-edge-sword. If you lean it too much, enough to get a periodic misfire, your hydrocarbon numbers will go through the roof.

  • Sknight

Posted December 29, 2011 - 04:40 AM

#6

Very true. I think he's going to need an emissions guy that will work with him some either way. "Failed again but closer? Let me lean that another quarter turn."




 
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