4meuwil

When idling my RB dellorto starts loading up real bad on the gsl-se......screams above 3000 but as soon as you let off to idle it loads up and dies. It has the correct jets in it and it just decided to start this one day.......any clues?

knight1976

what are the "correct jetts"?

DriveFast7

iTrader: (1)

what jets are in there right now?

if you search the forum you'll find my and others jetting reccomendations for 13b.

FYI my rotary truck pictured below has 4port 13b streetport. 82 idle jets work best so far. it had 75's in there and i reamed them out to 82.

the idle fuel jets might be plugged with junk. remove them. pull the fuel jet out of the idle jet holder and clean them both with spray carb cleaner

Wankelguy

I'd try a Power Foam treatment first, and see if that doesn't clear up the problem. It is a little harder to do on side-draft carbs as you can't fill up the carb with foam and let it sit like you can on a downdraft carb, unfortunately.

bill Shurvinton

I have had that problem. Ended up being a leak from the pump circuit. Take the airfilter off and, with the engine not running pump the throttle. You should see a squirt of fuel from the pump jets then nothing. In my case it would dribble for a while.

Swine to diagnose as the car would run fine, then misbehave, then run fine again.

But reading the symptoms again, if it runs badly below 3000 and fine above it rather than just idle, then the entire idle circuit is messed up and you have to start by checking everything, starting with throttle position.

PM me if you want a check list

Bill

knight1976

Bill you absolutely are the man when it comes to sidedraft info. oops did i say that outloud?

dvcn

1) verify correct fuel pressure
2) verify that the needle and seat aren't bypassing

4meuwil

regualtor has been replaced and fuel pressure verified......tried everything from 2psi to 4.5 psi with no luck.

haven't taken the needle and seat out to check for wear in fear of breaking that tab. I have verified that with the car running (badly of course) there is no gas coing out of that overflow hole to the front of the car by the air horns....

all jets are the ones put in by Racing Beat....i believe its 80 idle and 140 main if i remember correctly....either way i checked every holder, jet, etc. to make sure it was racing beat specified...

i had to use the idle adjust screw to idle it up to even get it to run without my foot on the gas.

any more help is greatly appreciated.....tired of seeing my baby sit.

dvcn

No need to remove the float. You can check the float level with it on. You can test needle and seat function with it on also.

Try this: With the car idling (poorly), turn off the electric fuel pump. If the car instantly idles better (before running the bowls dry), your float level is either way too high or the needle and seat are bypassing.

The jetting from RB is really good and works on a very wide variety of setups.

You don't need to break the aluminum 'ears' to get the float out. The pivot/hinge pin slides out lengthwise, you don't pull it straight out. (I've broken it before, had to have it TIG'd back)

4meuwil

I'll give that a shot....thanks.

4meuwil

i have been trying for months to find the right wire to jump to make the fuel pump come on with the key....used info off here and wiring diagrams in the FSM i have....no luck. I was going to use that to see if the needle was shutting the gas flow into the bowl off correctly.

knight1976

Shoot me a pm i have some pics of how i did mine. They should help ya out, i know when eddierotary showed me it made perfect sense.

*EDIT - May save ya some time. I removed the fuel pump relay( passenger side floorboard) and gave the fuel pump wire ( blue with green stripes i believe) a switched 12 v signal. So whenever the key is turned to the on possition it automatically sends the fuel pump a 12v signal.

On a sidenote what regulator you using?

4meuwil

using one of those silver purolator regulators......

thanks for the tip on the fuel pump relay.

DriveFast7

iTrader: (1)

buy a big can of gumout carburetor cleaner. remove all the jets. spray that carb cleaner liberally into every orafice and spot a jet goes into. flush all the crap outta it. could be a gasket or gasket sealer came loose and is plugging a pathway. i have seen some carbs with sand/crud in the bottom of the accelerator pump housing from not using a fuel filter... that stuff comes loose at the oddest times.

it would be a good idea to put some shop towels in the carb body to absorb the carb cleaner.

what jets are in there? what is your exhaust setup? i'd be happy to provide my jetting reccomendations but need info.

you might have a dellorto carb jetted for a 12a; which is insufficient for a 13b 6-port.

for starters go with 80 idle fuel jets.

4meuwil

its got 80 idle and 140 main i think.....the same numbers provided by racing beat and gruntled.com.

the carb has been on this 13b for about 2 years but sat alot....it ran great for a month and then one day while warming before a cruise, it started idling like crap and gradually got worse.

i completely disassembled the carb and cleaned out the slime and sand that was in it.....used 4 cans of carb cleaner and about 10 minutes of 120 psi air pressure to clean it out.

BUT i just remembered......when i took it apart there were two parts missing......they some sort of weights that sit on top of too ball bearings....they wree not in there when i took it apart so i figured it was one of those top secret RB mods before they sent it out.

Got it all back together after being thoroughly cleaned and still no idling......

I bought the dellorto book but haven't had time to tear that carb back down...

Can anyone with a dellorto verify that those weights should in fact be there? WHat do they do?

4meuwil

http://www.gruntled.com/Dellorto/Diagram.html

part number 50 is missing....one on each side of the carb were not there.

4meuwil

exhaust setup is RB header (not off road) and 2" stright pipe all the way back to muffler......same as on the donor car.

5th and 6th ports are wired open.....but it doesn;t help to close them, i tried.

4meuwil

How much do you think it would cost to just buy everything i can new for it, gaskets, float, needle and seat, and those weights?

i need a dellorto rebuild!

DriveFast7

iTrader: (1)

you don't need those weights part 50. just the two check *****. i know, i tried two different sized weights and it didn't run as good.

sounds like you cleaned it out very well.

buy a rebuild kit for $25. the #300 needle and seat is nearly impossible to find these days. floats are roughly $20.

2" straight pipe isn't very big but nonetheless that is a low restriction exhaust system and i would go with 240 main fuel and 220 main air. if it stumbles when you just tip-in the throttle, try reaming the idle fuel jets out to 82.

4meuwil

best place to get rebuild kit and float?

DriveFast7

iTrader: (1)

I get lots of my dellorto stuff from:

European Motorworks
13224 Prairie Avenue
Hawthorne, California, U.S.A. 90250

Telephone (310) 644-8038
(800) 722-8678 in U.S.
Fax (310) 644-8042

Hours:
8 am - 5 pm PST, Monday through Friday
9 am - 2 pm PST, Saturday

email us: sales@europeanmotorworks.com

4meuwil

i adjusted the improperly set float and she idles now.......i think i adjusted it too far though, she's running out full when it really quick....got some more tinkering to do.

dvcn

Good job 4meuwil.

Here are some instructions on setting the float level:
http://www.lotuselan.net/publish/lsb...rto_dhla.shtml

Set the level to 17mm.

I previously asked about the fuel pressure. Did you check pressure with a decent pressure gauge that you can read at idle AND at full load (7000 rpms, 3rd gear)?

To make things easier on the needle and seat, I like to run a fuel pressure regulator that has a vacuum (and boost...) reference. This will drop the fuel pressure at idle or when the vacuum is high and the fuel demand is very low.

4meuwil

I will try to get a remote setup so i can check the pressure under load.....

SO i would benefit by running a boost style regulator even though I'm NA?

Thanks for everyone's help....my childhood dream car is finally becoming a reality......