carburator jets, accuracy of carburator jets. Options

[ME733]

(IMG:style_emoticons/default/popcorn[1].gif) well gang just reciently there have been some posts about carburator jets, air correction jets,jet carrier, and their location, and how to read them. My question is this. For those who have measured /verified /checked the accuracy of Jets, (both air and mains) who would you recommend , and who would you purchase them from?. I ask the question because some "new" jets I have collected are a little off. examples, 120,s were 130,s, 125,s were 135,s, 130,s were 145,s...etc., it,s easy enough to drill out a small jet and make it larger.(with jet drills) but this doesn't work in reverse naturally. So who would you recommend for new accurate Jets! or other accurately made carburator parts. (IMG:style_emoticons/default/popcorn[1].gif)

[tat2dphreak]

aircooled.net

aircooled also has mid sizes like 57.5 and 52.5 and john will even help you fit a set that matches your application, if you want advise

[IronHillRestorations]

If there's any question you can check the jets with a jet reamer. Just find the reamer that fits and slide the jet down the taper and mark it with a sharpie, and then check the other jets to that mark.

The other thing I've found is that most jets are a little smaller than the appropriate jet plug gauge, if that matters.

[GeorgeRud]

Don't know if he's still doing it, but Rich Paar @ PMO was always helpfull in the past when I needed parts for my 914-6.

You can fax him and he'll get back to you. I know he had the business up for sale, so maybe someone else has more current information.

[jmill]

I like Pegasus. http://www.pegasusautoracing.com/group.asp...upID=WEBERIDFPJ

[type2man]

http://www.cbperformance.com/category.asp?CategoryID=6

[jaxdream]

You could also do what a guy I know used to do to Harley S&S carb jets , solder them up with solder , redrill with the jet drill size you want . Could be a easy fix in a tight spot, any who just an idea , cheap except for the jet drills.

Jaxdream

[DBCooper]

You could also do what a guy I know used to do to Harley S&S carb jets , solder them up with solder , redrill with the jet drill size you want . Could be a easy fix in a tight spot, any who just an idea , cheap except for the jet drills.

Jaxdream

Exactly what I do, and not just in tight spots. Ever notice that even with a big collection of jets you never seem to have exactly the right size? Or you can only find three? It's one of those unwritten Laws of Life things, like toast always falling jelly side down. So for me drilling is the easiest and cheapest way to jet carbs. Start small and go larger in steps until it's too rich, then lay on a layer of solder and ream it back to the right size. If you're really anal once you know the right size if you have them in your box you can put in new unsoldered jets, but I never have.

[Mark Henry]

I've been tuning with a wide band and jet drills for quite a while, used a narrow band and plug method before that.
Very fast job now, no waiting or time wasting.

[sean_v8_914]

I'll second that!!! get access to a wide band. beg, borrow, steal. whatever you gotta do to get one. once you use one you will forever wonder why anyone would play around without it.

[jaxdream]

I would venture to say that I am very ignorant when you guys talk about wide band tuning (IMG:style_emoticons/default/WTF.gif) , i have to ass u me that you are talking about wide band oxygen sensors , just not sure how you get the data to interpret. Sounds like a very good idea , but I wolud like someone to enlighten my dumb ass . I am very curious as to the instruments / tools required to accomplish this task. Thanks be to those so inclined .

Jaxdream

[jmill]

This is what I have. It's older than dirt but works great. I throw in a set of jets and go for a spin with the unit all hooked up. Find a big long hill put it in a higher gear and stomp on it. Check where your at, rich or lean. Poor mans dyno tuning.

[jaxdream]

That's great , exactly how do you hook it up ?? I have a staionary ( big ) exhaust gas analyzer , haven't messed with it yet , that sticks up the tailpipe ( proctoligist style ) . I'm interested , your's appears to be an older unit , please tell me more.

THANKS jmill

Jaxdream

[jmill]

This one does the same thing. You slide the probe up the tail pipe and then hook it up to the 12v battery. There is enough wire to have the unit on the passenger seat. I duct tape the wires to the body of the car in spots so they don't get hung up and ripped out.

[charliew]

I don't live in town and soldering jets always seemed to be the thing for me. I never used a jet without trying a drill in it to see what size it was before going to a different size. Course it also needed to be acid core solder that was stored away from anything you don't want rusted.

My first attempt at shade tree carb tuning was a two one barrel setup on my straight six chevy. Took it out on the hwy to check it out and it backfired and started burning (no hood or fenders). It just happened to be in front of the local airport and they saw it from about 1/4 mile away and came and put it out and I drove it back home. The only problem was I drilled too many things out and had to go to the junkyard for more carbs.

Many years later I drilled some jets on my t1 and didn't try it on the hwy and the next monday morning I had to drive about 100 miles to school and it would only go 60 in third, boy that was a long 100 miles. At lunch on monday my classmate took me to the local vw dealer and I got some new stock jets to put back in it.

[Mark Henry]

Wide Band O2 meter, sensor goes in the exhaust, has a digital read out on the dash. Tells you the exact air/fuel ratio, flat spots will be seen, lean and rich readings are instant.

There are some cheap systems out there now, worth investing in, cheaper than a leaned out engine.

[jmill]

My old heathkit is a narrow band and it does react slower than the newer wide band units. It's analog and you can't split hairs with it like a digital unit. It does have a few things going for it. It's cheap, no need to weld an O2 bung in the exhaust and it's portable. It's payed for itself about 20 x's over.

[jaxdream]

Thanks guys , went to evil-bay , found a couple of jmill's outfit , a lot of wide band setups . Will save the pennys up for this deal , which really seems to be a great idea as far as tuning engine with carbs . Some time back i read a post from a fellow who raced , said it was the best way he could keep engine tuned good , and keep competitive . Thanks again for the info.

Jaxdream

[Mark Henry]

Personally I'd pony up and get a wide band. I used to have a Haltec narrow band for ages, but it only register's around 14:1.
Our engines tend to like around 12.5-13:1 AFR for best power and cooling.

[DBCooper]

+1