Carb Problems

[GilBeQuick]

Ok guys, I picked up the OS #20E carb used, I've had it on my 8 Port for a few days now and can't get it to run for crap. I've tried everything, I just can't figure the dang thing out.

The best I can get it to run ok is just putting around at about 1/2 throttle. Anything more than that and it dies. Doesn't matter if I lean it, doesn't matter if I richen it, it just dies. I can get it to idle all day long though. I'm completely stumped.
Even if I have the HSN 2/12 turns out it runs blubbery rich. I thought I had it running ok for a second, then it died again so just for the heck of it I checked my HSN setting and it was 1/2 turn out! I'm suprised it was running at all.

Is it possible that the carb just needs to be rebuilt? If I take the carb about, what should I look for to tell me it's time for a rebuild? I've never rebuilt a carb before....are there specific kits out there that include new needles and such?

Help please, I'm about to go crazy with this mofo.:madface:

 

[mcvickj]

Rebuilding a carb is pretty straight forward. Go to the OS website for a blown up diagram of the carb and replacement parts. Worn O rings, broken tips on the needles are the two major things I can think of.

I would suggest getting some AE Green Slime and lube the O rings before you start putting the carb back together. That way you run less of a chance destroying em during the rebuild process.

 

[GilBeQuick]

Completely taken apart, everything looks fine. All o rings are in good shape and no needle tips are broken.
Maybe I just can't tune for crap!
What are the stock setting for this carb? 3 1/2 on the HS and 1 1/2 on the LN from flush?

 

[olds97_lss]

Just a thought, but did you try a new glow plug? I've had symtoms like you described and it was a glow plug on it's last leg. It wouldn't get hot enough to keep up with the fuel on high throttle.

 

[GilBeQuick]

Yup, I also thought the same thing. Just to be sure I've tried 3 different plugs.
I'm gonna put the carb back on and mess with it some more today if I have time. Hopefully it'll run right.

 

[lykan]

Slide, or rotary? I had the same problem with a 10E. Come to find tou there was play in the carb from left to right. Slop in the carb itself. Left to right slop made the LSN vary depending on pull, could never get a tune. Went back to the stock carb.

Maybe check for in out/left to right slop? Jess an idea

 

[GilBeQuick]

Hmm.... what do you mean by slop? What would I look for?

 

[nitromaniac]

GilBe! Do you still have the stock(8 port) carb laying around? If you do, take a good look at the inside(needle) dimensions of the 8port carb and see if your setting the os carb the same way, I know this is gonna sound a bit crazy, but the needle and slide settings may be just a bit different from carb to carb, you may have to just eyball the settings to get it to run enough to find a decent starting point to tune it! Os carb settings may say 3 1/2 turns out, that could be five turns out on a stock 8 port carb! Or visa-versa, who knows, But if you can hold both carbs together and try and set them by sight, you may find out that you are dealing with a much larger gap on one over the other, Its worth a try anyway!
just to cover my ass here, I have never tried any of my OSe carbs on anything other than an OS mill, I am just trying to help with a possible logic theory! Good luck and let us know!

 

[lykan]

Maybe this will help, does the throttle arm move in and out, or side to side like in this picture?

 

[GilBeQuick]

Thanks for the advice!

Lykan, it moves in and out, not side to side. I see what you mean by slop now.

I took the carb completely apart, inspected all parts and everything is just fine. Hmm, so what could be the problem? I cleaned everything and oiled the o-rings, then put it all back together. I noticed a couple of small cracks in the carb's rubber boot where it slides onto the carb, so I siliconed that all up.

After it dried I slapped that mofo back on the buggy and went outside (about 40mins ago) to test and hopefully tune.

Crap if I know what was really the problem, but she's running like a champ now! Temps are down about 15 degrees from the stock carb and the midrange bog is gone....just solid, very quick accelleration from a dead stop all the way to the top!:buggy1:

Thanks a lot for all of the help. :thumbup:

 

[olds97_lss]

You might have had a bit of gunk on one of he needles and with all the futsing, knocked it off.

Who knows, but good news is good news regardless how you get it.

 

[bhwilder]

I have the os 10d on my t maxx and it's a screamin demon.
From what you said, I take it your 2 1/2 "OUT". OUT meaning - richened?
I had the same problem - until- I decided instead of getting pissed off that I had nothing to lose and went the other direction - don't got "OUT" go "IN"!!!
Most carbs are not done this way but what the hell if you're all tore up about it, it's worth a try huh?
Put your carb on the factory settings
HSN - screw all the way down and backoff 2 turns
LSN - screw flush with the throttle body and turn "IN" 2.5 turns,
yes, that's ""IN""
IDLE -

I have the os 10d on my t maxx and it's a screamin demon.
From what you said, I take it your 2 1/2 "OUT". OUT meaning - richened from factory settings?
I had the same problem - until- I decided instead of getting pissed off that I had nothing to lose and went the other direction - don't got "OUT" go "IN"!!!
Put your carb on the factory settings:

HSN - screw all the way down and backoff 2.5 turns
LSN - screw flush with the throttle body and turn "IN" 2 turns,
yes, that's ""IN""
IDLE - don't bother with yet
The engine should run, now start tuning.
HSN - The vehicle is going to run like crap, but don't worry, You have to find the point on the HSN where the vehicle is dying out or close to it, you'll be able to tell, trust me, make small increments to lean it out to the point it's dying, once you find that spot, Richen the HSN 1/4 turn. That will keep the buggy up and running and in good shape.
Now for the LSN,
On the OS carb, you're not going to be richening any on the LSN, and I mean any, as a matter of fact by the time you're done with the LSN, it's actually gonna be about 1/8th to 3/16th" "IN" and you can see it plan as day so remember this, the LSN is gonna be screwed ""IN"" and you can see it. If you had a tape measure small enough, you could measure it and see how much it's screwed in, at any rate, I take this is in a car or truck,
I started the LSN settings (after the above mentioned HSN was done) by leaning it 2.5 turns from ""factory settings""( so from the LSN being started at flush with the carb body, your gonna turn that sucker in 4.5 turns, which will be close to 1/8th or a little more in by the looks of it) and started making runs at wot. Keep making turns at 1/8th" (once you get it to were it's really getting close to screamn' start tuning it in very very small increments) until it starts to die, What I done on my tmaxx was when it got to the point that it was pulling wheelies out the ass, I was done, Just keep turning in at small increments on the LSN. Be very patient, it could take a couple of tanks of gas to get it there, but be patient.
As for the Idle - pretty much anyone can set it, just set it low enough to keep the truck going at idle and doesn't die when you get on the brakes. Some people set it to their own preferences.
And that's how I done mine and it's a screamin demon.
Mine runs at an average of 250 - 263 and runs damn good at that temp.
Any way, that was for my Os carb and my brothers Os also, maybe it'll work for you.
Let us know.