Can't pass emmision test!

[tempebru]

My 1978 GS 750 has been pulled out of storage and completely gone through over the past year. New pistons, rings, valve job. Every seal, gasket and "O" ring has been replaced. It runs like new! I was ready to get new tags for it untill I couldn't get it to pass the emmision test. Hydrocarbons were 1635 ppm with a limit of 1800----PASSED. Carbon Monoxide was 7.5% with a limit of 5.0%----FAILED. I have a 4 into 1 with K&N pods on it. It had the same setup before goinig into storage and passed before. The carbs are still running the stock (#15) pilot jets and 107.5 mains (which I think are a little lean but I haven't been able to do a WOT chop and read the plugs....would like to have a plate on it first!). The needle is stock with the clip in the 3rd position from top (same as when I parked it). Air mixture screws are out 1 1/4 to 1 3/4 (highest rpm and back in 1/8 turn). I did back out the fuel needle screw to 1 1/4 from 5/8 to 7/8 to solve an off idle hesitation. I think I need to screw the fuel needle back in but would like some feedback before I waste a trip to the testing station. By the way, they ony test the bike at an idle which I have set at 1200 rpm.

[tkent02]

Move to another state.

[Tarbash 27]

what state has motorcycle emissions testing? Cali? You think it would be exempt by now.
Was the bike fully warmed up before testing?

[tempebru]

Phoenix, AZ . They test eveything from 1967 on... I have to have my Quad tested to keep a plate on it! And yes the bike was good and warm. It was 90 here yesterday and it's a good 10 miles to the test facility.

[Tarbash 27]

what? Im definately never moving to that state. I can just imagine trying to get my 67 honda to pass emissions. Theres absolutley no emission control on that thing and it burns so much oil.

[schlyme]

you would think cali would but we don't yet. i would suggest colortune but i don't know how that will affect the CO numbers. good luck.

[67fire]

ANOTHER State to add to my do not live there list!

Have you tried to retard the timing slightly?

Eric

[tkent02]

I would put the fuel screws back in, so what if it hesitates. They only test it at idle. Also are the carbs synchronized well? Synch them up and go through the fuel and air screw adjustment procedure again. Wait, I just saw that the engine was rebuilt, did you break it in thoroughly yet?

[SqDancerLynn1]

Check the timing, turn the idle down to 1K, turn the fuel screws to 1 turn out, make sure the coils have 12 volts, do the relay mod if you haven't done so..

[TheCafeKid]

Put it back to stock. Then tinker with it till it passes. Look on line for a chart showing what temps cause which gasses. It's possible ( and I'm guessing totally) that being lean (which makes your exhaust gasses hotter)
may turn out more CO than is allowed. I know that temps have everything to do with it and being too cool will raise one type and too hot the other but I've no idea which is which. Other than that your other option is to sell it and buy one that's bone stock with cv carbs. Those were set up to pass CA emmissions standards and even now should pass yours. Ohio used to have E-check, but thankfully they never tested motorcycles and on top of that any thing prior to 72 was exempt. They did away with it about 4 years ago but not before it cos me my beloved 1978 Trans Am with a 400BB and BM slapstick, had a race grade cam in it with posi rear end and straight pipes. Ran sub 13 on pump gas in street tires. I loved that car but the cam was so big that you had to two-foot it at lights or it would lope to a stall. Reeked of gas at idle. No way it would pass. But oddly enough my 78 Ford F-100 with a 5.0L mustang engine and straight pipes did. Didn even have cat converters on it. (I had the shells on the pipes bu they were empty. They won't even test em if they don't see cats on it. ). E-check is a rip off though and I will tell you how I know. I took my Mercedes 300SD to get checked once. They test private owned diesels here (or did anyway) that thing blew soot like a tractor trailer and the soot limit was 20ppm. The test registered 0.00ppm. It fast passed. Bunch of BS is what E-check was. They stopped here after a public outcry and multiple studies showing that the testing wasn't detering polution levels. (duh this area had multiple GM plants and numerous industrial areas spewing CO)

[first timer]

ever think of registering it in tucson? they don't emission test bikes down here. My girlfriends gs550 with pods has never been sniffed.

Only thing i would think is if it has to be sniffed, turn the idle a low as you can with out stall and lean it our real bad, maybe take the lid off the air box or and/or remove the air filter just to get it to pass the test.

take a look here

http://www.azdeq.gov/environ/air/vei/motor.html

apply for collectable plates if you can, should be old enough that should get you around it. Other wise looks like you have to come down here or go up to flagstaff.

[Charlie G]

Tempebru,

I can't help you on the adjustments for your bike. I'm wondering where you are, that they require an emissions test on a motorcycle? I don't think they require that in California and I thought California was tough. Edit (Missed you later posts)

Charlie G.

[Deano]

I had the same trouble with my 77 550 which is pre-smog .never had to test in cal. in fact maricopa county is the only place in the U.S. that it would need to be. Yours is close so a little fine tuning should get it to pass. pm me if you need a hand with it .

[Kris V]

Run some race gas in it California is not far behind They are talking (if they do it) 2000 and newer bikes will have to meet emissions. Good luck finding anybody that is state certified or a shop that will spend that kind of $$$$ to do it

[duaneage]

Find a place with a gas analyzer adn try to adjust the idle air screws until it clears up.

Sux that a 32 year old bike has to go through this. When you consider the small size of the engine it's not polluting much anyway.

Some states have mileage exemptions. PA, for example, has a 5000 mile limit by which any car driven less than 5K is not tested. Hot rodders of late model cars use this to register their street rods.

Higher temps caused by lean usually generate more NO (oxide of nitrogen) while your high carbon output and CO may indicate it's rich a bit. Lower rpms will help, and have the bike FULLY warmed up. Cold engines blow worse than warm.