Smog Failure--One Category--Need Input

Hersir · Post by **Hersir** » Wed Mar 31, 2010 8:16 pm

I'm in the process of registering my Pinz in Nevada and took it in for a smog test before going to DMV. It's a stock '75 710M that just had the fluids changed. It passed all categories except idle for CO (allowed 2.5%, tested 8.5%). It's running great and has stock carbs with 125 jets (previously housed at higher elevation) but thought smaller jets might just help with smog.

I'd appreciate any help anyone might have. I'd like to get the Pinz through smog and DMV and on the trail!

Thanks!

milesdzyn · Post by **milesdzyn** » Wed Mar 31, 2010 9:58 pm

Tips for Reducing CO during Emissions-Testing, From a site I researched a while back. I did #1 and manually kept the idle #2 at the high end during the test. I will be implementing #3 when I put new bases on my carbs later this year.

1. Lean out idle mixture slightly -- Normally, the best proceedure is to set the idle mixture for the best idle speed and smoothness, and then lean it out to reduce idle rpm by 100 to 150 rpm. Then increase the idle speed back to specifications or slightly higher.

2. Increase idle RPM slightly -- Typically, an idle speed closer to 1000 RPM provides reduced emissions. Note that this may tend to intensify "shutdown dieseling." Shutting down "in gear" will usually eliminate most shutdown problems.

3. Lower carb float level slightly -- When rebuilding the carburetor, you may want to reduce the float level very slightly. Sometimes a slight reduction of 1/64" to 1/16" can reduce carburetor bowl overflow by a significant amount (especially important in hot climates).

Miles

lindenengineering · Post by **lindenengineering** » Sat Apr 03, 2010 11:31 pm

First question.
What is the CO @ idle 850r/m AND what is the CO count at 2200/2400?
Second question:- Also what is the HC count at both rev samplings?

Lastly what are the limits for the truck in the test (your) State AND is the correct limits applicable to your truck in POUNDS.
Remember the weight limit is in KG's on the vehicle ID plate--some testers can't read nor calculate???

Dennis

lindenengineering · Post by **lindenengineering** » Sat Apr 03, 2010 11:37 pm

First question.
What is the CO @ idle 850r/m AND what is the CO count at 2200/2400?
Second question:- Also what is the HC count at both rev samplings?

Lastly what are the limits for the truck in the test (your) State AND is the correct limits applicable to your truck in POUNDS.
Remember the weight limit is in KG's on the vehicle ID plate--some testers can't read nor calculate???

Dennis

Hersir · Post by **Hersir** » Mon Apr 05, 2010 9:11 pm

Thank you both for your replies. I don't have the smog paperwork in front of me regarding the failed smog test as I'm out of town but I made sure the tech for the failed smog test converted the vehicle weight from kilos to pounds. When I took the Pinz to the 2nd echelon smog shop for diagnosis and retest I could see fuel leaking from the carbs and had actually lost power and stalled during the drive over there. I'm pleased to report, however, that a carb rebuild solved the problem and has the Pinz is running great. The second smog test was successful as well on all accounts (by a good margin) and I'll be off to DMV soon to finish the registration as a Classic Vehicle in Nevada.

lindenengineering · Post by **lindenengineering** » Mon Apr 05, 2010 10:21 pm

Good
All's well that ends well !
Sounds like Shakespear

Dennis