Nicholas7620

FROM DATZENMIke _______________________________________________________________ "Try for one in the high 90s for the primary. Secondary can be much richer as it's for full throttle use. (Mike I have a #104 now in the secondary now. I very seldom go full throttle.) My 710 came with a 99 jet and while it ran very well, this was really for higher altitude where the air is thinner. Indeed the car is from Nevada average elevation over 5,000 feet. I got a 112 jet from a local L20B (sea level) and performance was actually increased! As Q-tip said.... more air needs more gas and with more power you can run it with less throttle. On holidays this summer I averaged 30 MPG US. Even got a tank @ 35."________________________________________________________________________________ The smallest main jet is a #108 and the largest secondary jet is a #43. I'm wondering if after the passage of decades of use on a Hitachi carb if the jet's hole becomes larger? The brand new #108 looks smaller than the used #102. OK, so my plan is to use the #102 in the primary and #43 as the secondary. If I get better gas mileage I would like that. We will see. I also plan to lean down the carb one setting.

I'll let every one know what I did to pass. I received my #102 jet and #140 jets from NCI and I received a #108, #42 and #43 jets from jetsrus.com. The #145 is the stock secondary jet. Right now I have two #104's in my carb which resulted in avoiding the dreaded GROSS POLLUTER class to a lesser class of just FAIL. I'm at 3% CO and I should be at 1%. The #108 ... I received from jetsrus.com appears smaller than the #102 I received from NCI. It's hard to tell. I'm thinking of using the #102 and #43 for the primary jet and secondary jet, respectively.

The choke is not on. I can change the carb setting another notch to the lean. No it's not the original carb. I may have returned the original for a core. The carb is a rebuilt carb by NCI. The carb is over 40 years old. The jets could have been enlarged. I don't know. Changing the jets was the first improvement in CO readings. I did every thing else new air filter, plugs, rotor, cap, plug wires, change oil all these changes led to GROSS POLLUTER. I'm just in a fail category and NOT GROSS POLLUTER. I have a 102 jet which NCI, the carb rebuilder, sent me. I'm pondering whether it's worth the effort to change from a 104 to a 102. Both the primary and secondary are #104 jets. Which jet should I reduce to #102? The primary or the secondary? Is there a way I can make the jet smaller. I ordered just now several Hitachi jets #43's. It might take 10 days to receive them. Changing Jet size appears to be the only option. If I could buy a brand new HITACHI DCH 306 - 11A, I would. The DCH 306 - 11A is the California carb for a manual transmission. That original carb passed smog /was good for 30+ years. These rebuilt carbs are good for two years and then fail.

Picture of my wrench with the sides ground off to increase travel of wrench. I threaded a piece of green yarn through a hole I drilled. I lost a similar wrench two carburetors ago.

This is my GROSS POLLUTER fail. Whew my CO% are very high because Gross Polluter is only ~3% and my reading is over 11%.

IF I was high on NOx then the CAT could be the problem and the EGR, PCV, maybe SMOG PUMP would also be the usual suspects. Since the readings are high for CO then the intake side is the problem which could be vacuum, carburetor, choke and too rich of a fuel mixture. Here is my new smog test for today after I put in a #104 carb jet for the Secondary thus reducing the secondary jet from a #145 to a # 104. I also replace two suspect vacuum hoses and leaned the choke one setting. As you can see I had significant improvement from GROSS POLLUTER to just Fail. I improved from ~11% CO at 15 mph to ~3% by reducing to a #104 secondary jet, I'm encouraged because of an 8% improvement. However my CO% should be less than 1.52% at 15 mph. I improved from ~7% CO at 25 mph to 2.10% by reducing to a #104 secondary jet. Again I'm encouraged because of a 4%+ improvement. Before changing jets I couldn't get any improvement in my CO readings no matter what I did.

I failed again. The smog tech and I couldn't get any improvement in CO emissions, I'm still at 11% at 15 mph and 6.8+ at 25 mph. I've talked with Nat'l Carb and they're suggesting I try smaller jets. Nat'l Carb is checking to see if they have smaller than a #104 but I'm wondering if I can swap out a #104 for the #145 from another carburetor because I fail at high RPM's.

Where do I get smaller jets to decrease the size of the primary jet of my B210. It's a Hitachi carburetor. Found a website. My Primary is a #104 and secondary is a #145. http://www.jetsrus.com/a_jets_by_carburetor_type/jets_hitachi_main_4H7.html

I didn't pass. The advance was down to 5 degrees instead of 10. It looks like the advance is moving around. After I set to 10 degrees and checked it again. The advance was up to 20. So I lowered it back to 10 adjusted the idle to 700, then smelled the exhaust. No smell. The B210 idles good. I'll go in tomorrow AM and bring my timing gun, tools and check everything again at the smog shop and see what happens.

I tested my choke connection and the plug was not live and I replugged the choke to a live plug. I went to cold start and the choke opened as soon as the engine started. I'm fast idling at 1400. EVIDENTLY, my choke was connected to a ZERO voltage plug. Yikes, I was screwed from the very get go. I've never played with a circuit tester before and I decided to take the plunge and pulled out my circuit tester and there was no voltage going to the choke. I tested a nearby plug and it had voltage so I switched the choke plug to the live plug and the start was smooth and yes the butterfly was closed and opened upon starting .... so there was no gagging by the engine. I'm waiting for the choke to kick off , just checked, the temp is at 160 and idle is at 1550. Recheck I'm at 170 in temp and idle is at 1550. The idle is still at 170, 2 min later, rpms still at 1550. 10 min later temp is still at 170 idle is at 1700. I accelerated the choke off and the idle is at 750. I'm going to the smog shop and see what the readings are.

I use a cut in half 10mm and grind the sides of the wrench to increase the travel of each turn. I remove the surrounding EGR, air filter and the rest. I'll be able to access three of the nut fairly easily but the fourth one by the accelerator cable is the most difficul. I stay patient and turn the nut a half a turn until its semi-tight. then I'll cross tighten each nut. BUT BEFORE I do all this I attach the accelerator cable. I only start each nut 2 turns until they are all started. I've removed and reinstalled carbs on my B210 maybe 10 times or more. I muscle up my patience and wrench. Its great to have the magnetic tool from HF and putting a string on the wrench is an awesome idea. I lost one and never found it again. Putting catch towels/rags around the carb is also a great idea.

Check the air pressure in your tires. I average about 30 with by B210, I keep the air pressure at 30 psi and 38 if I'm going on long trips with freeway driving.

Don't shorten the cable. I found that if I shorten the cable then I will end up with a very high idle. I couldn't get my idle down below 3000 rpm until I allowed the slackness under the carburetor. I put all the slack back in and the idle returned to normal. There was plenty of cable tension to high rev the engine to 4K and more. (4K is my limit) If the cable breaks then replace it otherwise leave it loose. If you don't have a problem with the cable then don't fix it. Looseness is necessary.

EGR valve stands for Exhaust Gas Recirculation and I changed into a new one 2 years ago when I had high NOx reading. I'm very low and significantly less than smog allowance for NOx. The exhaust smells clean but because CO is odorless and colorless I can't tell squat. I'm supposed to be around 1% but the smog test machine put me around 11%. I'll try to get another shot at the smog emission tester tomorrow AM and if I fail again. I'll get the shop manual and retrace every vacuum tube tube and change out the smog pump to a rebuilt one I have from Cardone.