gonna do somethin to my carb

I'm getting quite frustrated now...the problem with my car has to be the carb, I can smell fuel....today it stalled and then i couldnt get it started cause the battery was almost dead anyways and the alt just keeps things charged properly...lucky work was a quick run away. It takes forever to start...first i thought it was cause it was lean and needed to be pumped full of gas, but i was wrong...i can sortaget it to start with out gas, but it will die about 3 times before i can actually rev it up to keep it running. I dont have the time or patience to deal with returning this carb (and paying extra for returning it) and possibly having problems with the next carb. I want to bore out this one again as i had good results with the last carb, but i'll take the fuel mixture part a little slower.

Why would enlaging the jet screw up the carb? wouldnt that just give a larger shot when u accelerate, or is there enough gas squirting out for it to work fine with the bored out venturi? the last carb actually had the most power with the massive jet, just ran waaaay to rich. and i dont know where the metering rod is set to so I'll just tighten it up a 1/2 turn to a full turn at a time. does it sound like the float could be too high? if i run my finger around the top gasket i can smell fuel on my finger, plus i can smell gas when its running....but what would explain the hard starting? timing maybe? i've adjusted it a few different times and it doesnt seem to start any better, just runs worse or slightly better than worse.

thanks for your help and wish me luck with this carb

This is a new, replacement Carter after some previous carb problems , right?...

It sure is...but it doesnt seem to be that great of a rebuild. might be wrong, but i know what the car runs like with a proper carb, but i dont think theres a single one that i had that was to specs, I suppose i'll do the basics first, such as checking the float setup and the metering rod and all that, then i'll go from there...it is a major PITA though. I've also decided to change the valcover gaske and clean it up a bit, i want to see what the rockers and springs look like as well, anything i can do while the valvecover is off? probably not eh! other than strip and polish it...hmmmm...would clearcoat protect a polished surface from rusting?

Me personally, I don't like the webers. I had a weber DGE or something like that for my 250 and it ran like poop, no guts and slow throttle response. So what did I do? I went back to the CARTER RBS it had originaly. It already had one, I just bought the weber to see if theres anything to the hype and, well, there was'nt. The RBS is a 215 cfm, bigger than the weber and SO much simpler in design and so easy to tune. There is only 1 gasket on the carb and it's a rubber o ring that goes between the float bowl and the carb...thats it. You take the float bowl off via 4 phillips screws and bam, you have your jet and metering rod right there all in one spot, and the best part is you can still get them and the rebuild kits are less than 20 bucks. very easy to do. If you find one in a yard somewhere, just soak it in gasoline for a day, then spray out with carb cleaner and use compressed air to fully blow out any varnish. usually carb cleaner works fine for me.

I think you have lost compression. That is the hard starting, the heavy fuel usage, low power/responsiveness.

addo":3i2wpu7s said:

I think you have lost compression. That is the hard starting, the heavy fuel usage, low power/responsiveness.

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Yup, all that raw fuel being dumped through the engine from that 'bored out' carb may have washed the cylinders. Definitely take a compression check. And check the float level.
Joe

Wonder if theres a way to see how much blow by is being produced? Like through the oil cap or something with the pcv valve hole blocked and let all pressure out through oil cap to test? I know my 250 is getting tired and has a bit of blow by when I do this. Mostly under hard acceleration. And I can't spin wheel from a stop anymore..and fuel mileage is well, bout 19 mpg when it was 23 when I got her so I think you guys are on to something.

I never thought about that until now and you have me worried about cylinder washing...I know what you mean, so much fuel that it was'nt being burned fast enough so wet raw fuel was being stuck to the cylinder walls and thus washing any oil there would be off and thinning it to bbot...leading to bad bad ring and wall damage. ouch. Thanks for saying something because now I will watch just how much fuel I'm dealing with from now on. I mean you really got to be dropping a lot of gas it seems.

sorry guys...forgot the compression test...i had it in another post, forgot it here though. the results are 120 thru all cylinders but #3 which is 125 so i have a pretty constant compression. I did a bit more fiddling with timing, i hooked up the vacuum advance to direct manifold vacuum and adjusted the hex screw in the canister (unscrewed it about 5 turns) seemed to give the best results when plugged and unplugged. It doesnt run half bad right now, but its still not perfect and very gutless, but i expected the gutless part since ive experience a few stock carbs before hand. I went and bought a valve cover gasket (rubber) and some battery wire (nothing really wrong with it other than a few bare spots here and there) so I'll also be able to get a look at the rockers and stuff...i keep thinking i hear a pinging...not like detonation, its more metallic than that, but its hard to tell. I also priced out a new water pump...not a bad price so thats in the to do list soon (do that with an electric fan upgrade) ...i think I'll ask for an alternator for christmas. other than that theres not much else i know...i should get an electrical test done just so i know how that part is. Oh yea.... i also have a half busted attachment for a manifols bolt so i do have a bit of exhaust leak, could that be causing problems?

Either way, do u guys think that i should bore it out, I'm gonna really really want to in the next few weeks, but how much richer would i have to make it, i think i did it wayyyy to much with the last carb and it wasnt running properly for awhile so it didnt realy recognize that it was that much richer (had a plugged hole) so maybe hen i unplugged the hole it recognized the exessive richness and that might have beed my problem, it was a carb from the junker so it may have even had a bad accelerator pump as well. this one is new so maybe I'll get better results with boring it out and richening it up a bit? thanks for all your replies thus far.

No. Don't bore it yet. Go to the store and order another carb and get it replaced first. I had bought a new carb for a chevette I had and had 3 bad carbs in a row. Unbeleivable I said. Just get it replaced, if you still have the same trouble...then you can rule out the carb so to speak.

You should be able to get your engine running smooth before you jet it.



Or, buy a rebuild kit for the new carb, and bore the jet out of the kit and try it...in other words see if you can maybe buy just the jet and try what you said, at least you can readily swap it back if it gets worse or stays the same..

I agree with Ronn- modify that carb and you will lose your rights to return it. I'd go through 2 or 3 rebuilt carbs before I decided whether the engine or carb was at fault.

hmmm...actually guys, today was fairly impressive...somewhat. I dont think I'll replace the carb yet, as i am now not totally sure its bad...not perfect but not bad either. I cant go WOT without it stumbling (still smells a bit rich when i floor it but possibly the gas isnt getting ignited properly and I'm smelling that?) or its too lean or rich which is causing stumbling, but either way i was still impressed today...i went to work and back and the gas gauge needle hardly moved...if it keeps this up then i will use it as an economy carb as it should be about 2-3 times better than its been on gas...of couse performance is still lacking. but right now I think i want something thats really good on gas....when i think the carb has more than paid for itself and i havesome extra $$$ than i will get a 2bbl and make the intake so i can directly mount a 1bbl or 2bb depending on the mood or $$$ crisis...not talking about a 2bbl adaptor, but rather grinding the intake and having 2 different plates that i can screw on for either a 1bbl or 2bbl. thanks for all the advice so far, i still dont think the carb was built totally right, but I'm gonna test it for a few moredays and if i continue getting good mileage than i will keep it...if my gauge reading today was false than i will return it and try another.

this is more of a different question, but i was wondering it today. IF your have a leaking valve cover gasket will u have a vacuum leak if the pcv is hooked up to the manifold? havent heard of it before but it sorta seems to make sense...and i do have a slightly leaky valvecover (just got a gasket yesterday and am replacing it tomorrow.

well i redid my valve cover gasket...nothing else was changed, and guess what. The car Idled 400 Rpm higher and doesnt feel like it wants to die at all when i stop. so i think i fixed the problem...musta been quite the leaky gasket...never thought it would have made the difference, bu i never changed anything else so that would be it. and i also have red valve springs...is that a stock kind?

Dave,

I agree with the others- try another carb. I got my 2nd YF yesterday- it is much smoother going down the road (I assume it is not too lean like the last one) but now it has off-idle hesitation :roll: I don't know if this is accel pump or what, but the last one did not have this problem.

I'm playing with my timing too. with 12 deg. intial and the vacuum line hooked to manifold vac, I had about 20 deg total at idle. I then hooked up to the ported vac. on the carb, and had no vac. advance at idle but the car is much quicker off the line and part throttle. Although some of the guys in the other thread said up to 25 deg. total advance at idle (about 15 deg of it vacuum) should be okay, in my case 20 is too much. I'm going to play around a bit and see if I can find a middle ground - but I think the hesitation is from the carb. I should have at least some vac. advance from the carb at idle, shouldn't I?

Thor

After spending several hours on my timing, I know that my new YF is defective, just not as bad as the last one. Not only is it not smooth at cruising speed (better than the last one- probably just a tad too lean) but it has an off- line hesitation. I think I need to figure out how to adjust the accel. pump- you out there, MustangGeezer?

Sedanman

On the PCV question, I'm sorry to disappoint but it should not matter if you had a leaky valve cover or not. IF the PCV valve is working correctly, it wouldn't matter if it was hanging in mid-air or hooked to a sealed valve cover- the PCV valve would only open to let air through under high manifold vacuum conditions. At idle it wouldn't let anything through.

I suspect you have a dirty and/or sticking PCV valve and just rattling it around while replacing the valve cover gasket made it temporarily seal better. The fact that you report changing engine/carburetor smoothness on different days anyway would tend to support this theory. Try spraying some carb cleaner in the valve and rattle it around real good to make sure it is loose, and if it's internal sealing surfaces look bad after that just throw it away and get new one.

hmm...good point mustang6....it is a fairly new PCV valve though, and it seems to be working properly (its loose) although it is still possible that its faulty, It does open at idle as i can pull off the PCV valve and it will be open (sucks my finger if i put it against it) and arent the highest manifold vacuum conditions at idle and at cruise, meaning that it should let something through at idle? either way, i fixed the gasket (painted it while it was off too ) and its fixed...hmmm...actually i also had to removethe brake booster line so maybe it was loose and when i tightened it it fixed a leak or something? oh well...I'm pretty happy now so i can rule out the carb and all else..now i need to worry about christmas presents (thankfully not the car anymore) i need to start saving up a bit now so I can afford some other things now.

sedanman..u have the tab type adjustment on your carb right (cant remember what u said before)

Dave,

Yep- I have the tab adjustment. I bent it up today, but am still getting misfiring about 1100 rpm. I know it is NOT ignition so it must be the carb. I'm going to bend it up a bit more tomorrow- if that does not do it I'll have to try a 3rd carb Time to start another thread on tuning the YF.....

so bending it up is how u richen the mixture?

i got a new PCV valve today, doesnt make a difference...but i did try retuning the car again since it runs better now. If i lower the idle speed via the idle speed screw below 900 RMP it runs rough, so i have it idleing at about 1300 RPM in drive, which drops to about 5-600 RPM in gear...no biggie.

placid warrior":1ngaicj0 said:

i have it idleing at about 1300 RPM in drive, which drops to about 5-600 RPM in gear...no biggie.

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I hope you check your u-joints regularly! I'd lower the idle back down to where it's rough, and play with your mixture screw and timing to see if you can smooth things out. My old 170 ran fine with 14 deg. init. timing, but my new 200 idles smoother at 12 deg.

Yep, bend tab up to pull rod out of jet more and richen- I think. I'm starting a new thread on this.....

actually i did my u joints last year, but i know what u mean...it does clunk into gear. I think i'm gonna change the vacuum source back to the carb port cause thats probably why i cant lower it so much (it starts the timing higher at idle and lowers when your driving) its pretty decent for gas mileage, but i really missed the power...it sucks for acceleration. so i want to find a happy medium between power and economy *well at least as much as it can get) I will be hopping up my carb or adapting a 2bbl in a month though.