I fired up my 914, and let it idle in the drive way for a while, and noticed that small dots of black stuff (looks like oil splatter) seem to come out and stain the concrete. These aren't liquid at all, but are a black powdery soot.

Is it normal to have these black soot marks? Do you think this is because my car has sat for some time?

Rich

Coming right after I put on dual carbs.....

I think you're right. Anyone know a good method to set the mixture? I'll have to re-read my dellorto superperformance book tonight.

That was an important part of the puzzle the fact that you just put on carbs.

Rich, rich, rich.

Aren't you the Terry Mason I've been trying to get in touch with?

I believe I goofed up and found a check of yours and we didn't send you some brake clips. Should I tear that check up? Do you need clips?

There should be two screws at the base as most of these Dellorto and Zeinith carbs are kinda Weber clones.

The smaller screw sets the balance between throats. Close them all down and read the one with the most airflow. Open the others up to match.

The larger screw is the enrichment screw. There are various ways to set these but, you should try to find an EGA. Otherwise, you can set by ear and idle. I don't have a 911 manual around me here but they give a decent method for tunning Webers etc...

E.

yeah, rich--do Dellortos have a cold-start enrichment (my Webers don't--what a pain in this weather--re-started 7 times before my artful flutter could keep it going)? If so, may not have come off to hot run position. We'll be watching with interest--"aw, shit, a grand into some new carbs, and I got this!"

Eric - don't worry about the check, I found some other brake clips that worked.



I thought the carb install went way to easily! I guess that's because I didnt' mess with the mixture at all . The thing runs great now (compared with the single weber I had before).

OK... I'm going to tear it up. I'll PM you the check number so you can void it out. Sorry about that. I had the clips sitting there waiting for the check and a shipping address... finally found the check burried in a "stack".

Sounds like you've got a good foundation on the carbs. Get a UniSyn gauge and start the fun. You may simply want to experiment by turning in the enrichment screws 1/4 each (if it's running great now). If you begin to get some lean "pop" you've gone too far

You can get them pretty even by pitch. I have used a piece of tubeing, put it

in your ear and the other end in the carb (one barrel at a time). Listen to the

pitch and match the others to it. But a syncgauge is by far the best.

I sat down with my Superperformance book, and looked at the section for setting the mixture, and it really didn't tell me much. I think that I'm missing a few of the underlying ideas. Are these two statements accurate?

1 The goal of setting the mixture is to get the engine as lean as possible without having any detonation

2 Detonation can destroy an engine pretty quickly.

Not to high jack this thread... but...

When I cold start my dual webber it generally takes a couple times to get her started and running smooth. I can generally find a little soot on the gagarge floor right after it starts, but none after it warms up. I just figured, that possibly due to my poor starting talent, a little soot is to be expected on an overnight cold engine. Am I way off?

I supplement my setting the way Paul does BUT PLEASE BE CAREFUL! IF THE CARB POPS (BACKFIRES) IT WILL DAMAGE YOUR HEARING! Please don't stick the tube into your ear.

Well, It's been a while, and I've finally gotten to work on my carbs. I've installed a new wideband 02 sensor, and have set the dwell and timing for my engine. Now I'm trying to dial in the mixture for my engine.

My wideband o2 meter starts off at 20 for about 10 seconds when I start the engine, then as the engine warms up, it settles down to a reading of 12. As I goose the engine, the readings go up to 15 or so, and fluctuate alittle, but eventually come back to 12 at idle


Per my dell book, I started the mixture screws at 3 1/2 turns out. I kept turning them in until I was only 1 turn out. My o2 sensor read 13, but the car ran worse, popping and backfiring whenever I hit the gas.

So now I'm sitting at 2 1/2 turns out, with a air fuel ratio of 12.2 or so. At this point, should I pull my idle jets (I currently have 60s on my 1.8L) and replace them with some #52 or #46 that I got off ebay?

hear about the islamic terorist asigned to blow up the bus?... burnt his lips on the exhaust

60s are pretty big. I would definately try something smaller. With my 40IDF webers on a 2.0, I run 50 idles and 125 mains, with each air bypass screw (do dells have these?) out 1.5 turns and each mixture volume screw starting at 3.5 also, but dailed back to about 2.5 before there is popping somewhere. I set all the mixture screws to whatever the biggest setting is so all cylinders are drawing the same amount. Make sure the linkage is square with the carb lever so both sides advance at the same rate.

look up the dellorto guy on Ebay. He is from Italy.
He knows these carbs really well, and he probably can tell you the right jets for the motor.
Once you find his ad on ebay, click on the "about me" thing in the top right.
He has a very nice web site with all the different applications of these carbs.

Sounds like you need to rejet it.

Rich

http://cgi3.ebay.com/ws/eBayISAPI.dll?View...userid=alfa1750

I found him, and you need smaller jets for sure.

Rich

Wow. We have the same color 914, we both just swapped out a single progressive for dual carbs...

with just about everything said here. Including alfa1750 on ebay. I just got a set of Weber jets in from Italy.

Thanks guys. These carbs actually came from Alfa1750.

I also got some new jets from him a couple of weeks ago, so I'll try putting those in this weekend and reporting back.

Just revving the motor makes you deaf!

I crammed the tuft of cotton off a Q-tip into my length of hose and it works great!

after the baseline setting are made, and you ensure that both carbs are flowing the same (droplink adj), the 4 idle/air mixture needle screws are not ness going to be set at the exactly the same # of turns in or out after that stage of the tuning. each one will be set for the best running of the engine. as you turn each one in to fully seated you'll hear an idle stumble and perhaps a slight black fire. you'll know when you hear it. slowly turn the i/a screws out, one at a time, for a smooth idle. the 50s are a better starting point for your engine. there should be little o-rings under the caps on the i/a screws. check their condition for cracks and deterioration if you sem to have one cyl that is unresponsive.

k

You should be aiming for 14:1 at idle, as adjusted by the air correction screws. Some where around 1 1/2 turns out.

Now go for a cruise and watch your AF meter. you should be hovering in the middle of the the gauge at 2500 RPM part throttle.

If it's rich you will need smaller jets on the idle cicuit.

It it pops and stutters as you push on the gas an the gauge peggs lean then you need to increase acceleration volume. Turn in the nuts on the linkage to the acceleration linkage (middel of the carbs)

Next after all this is sorted go to the main jets and find a place to safely hold it full throttle and see how it goes. and adjust main jets.

2.0L should be around .50 idle 130 main 200 air. But this is so subject to air temps and humidity.

I just went down to 135's from a 140 yesterday 40 degrees this winter I could pour on the gas now I can't I also hogged out a set of air correction jets to like 250. But I like to think I know what I'm doing ans why.

Which WBO2? LM-1? If it is an LM-1, be careful during startup. Although it is not advertised in the instructions, if you hit the innovate forum you will find that it is recommended to not power up the LM-1 until the engine is warmed up. If the LM-1 has self heated and gets hit with some raw unburned fuel (cold shock), it can get killed. Of course, you also can't drive for particularily long with it off either before you kill it as well.

As for the dells, make sure you have ~3.5 psi and your float heights are set correctly. When setting your float heights, make sure that the little spring loaded pin is not compressed at all during the float travel (this will prematurely close the needle valve).

I suggest getting some jet plug gauges, jet reamers, and at least a unisyn if not the better version (can remember the legit name) if you are going to try to get these dells dialed in perfect. The WBO2 will definitely help. Also, pull all the jets to verify what the jet sizes are (plug gauges are important here, jets can easily be reamed out and not marked correctly), if they are the same across the board, etc. Also check the e-tubes, you want 9164.2s. Verfiy that the acc. pump is putting out the correct volume as well (.2 ccs I think).


-Chris

Thanks for all the help guys!

Take a look at this video - http://www.drunkencrab.com/wbo2.mpg

You should be able to see my rpms, and the associated AF mixture.

I'm making real progress, but is still seems to lean out when I hit the gas

Are the pumps squirting? Is the pump volume adjusted to .2cc? What size are your pump jets? Could be the cause.

-Chris