Stock hitachi running rich?

[Boom death]

So I took my truck out for a spin this weekend put 11 gallons of fuel in her belly drove from riverside to long beach about a 120 mile round trip and I barely made it home fuel gauge was showing empty ... So I thought maybe my gauge isn't right so I dropped the tank to see and literally no fuel in the tank ... Truck idles just fine and drives fine but at about 11 miles per gallon I rather drive my supercharger Tacoma 3 times the horsepower and twice the fun

Any ideas on how I can fix this

[datzenmike]

Choke on or flooding carb could be the cause. Is there black smoke when driving? Take a plug out and inspect. Black dry and sooty could be the choke on or flooding carb.

 

 

 

 

Is the choke on? Take the air filter off when warm and look to see if the choke plate is closed or partially closed.

 

When idling, look at the front of the carb. There is a sight glass that has a horizontal line or a round glass with a dot. Gas level should be at the mark.

 

 

 

[Boom death]

so i looked and no black smoke at all only a little grey smoke at start up.

i took a plug out and holy blackness blacker than black and wet

when the car is off this is what the carb looks like its like partially closed

when the car is in warm up stage this is what it looks like almost no difference

after 15 min warm up kick the gas pedle so it can settle down this is what the carb looks like fully open

 

and at idle, warm up or the vehicle off the little sight glass with the dot barely shows any gas in their

and i dont know if any of the above is normal??

[Rays74]

Plugs are rich.......although those are Bosch plats which IME are Shee-ite, I would use NGK BPR5ES or 6's gapped at .040in if you're running pointless. Take and give the truck a shake as you're looking at that little site glass and mite be easier to tell if the level is above or below the dot.

[datzenmike]

The choke should warm up and be off in as little as 7 to 10 min average and should look like this....

 

 

 

Any gas smell? when taking the tank out? If you refill it be sure to look for any dripping or wetness.

 

Was this a sudden drop in mileage?

 

.

[Boom death]

Thanks for the input guys ... I don't think this was a sudden drop in mileage I barely use this truck and when I do it's on short trips around the block so never really noticed dramatic fuel consumption .. I did have this carb rebuild by a guy and I'm pretty sure he probably didn't set the air fuel mixture right and I have no idea how to check that lol ... And I checked the glass sight again and fuel seems to be like a 1/4 of an inch below the dot

[Rays74]

Also on an outside chance, might wanna check that the main jets aren't swapped, Boom D..........that would esplain the wet plugs and you supporting the oil industry so well ;)

 

Primary side (smaller butterfly) jet = approx #98 thru 107

Sec side........................................= approx #160 thru 170

[datzenmike]

Yup that's the next thing to check. It's easy to get them swapped.

 

I cut up a 12mm spanner so I could remove the plugs just below the sight glass on the front of the carb. A stubby screwdriver with the sides ground down will reach up inside and the two jets can be removed and checked. Or remove the carb and do it.

[Boom death]

Lol u guys make it sound do easy i don't even know what a main jet looks like but from mikes description it sounds like its on the bottom of the carb, right??

And I'm assuming one would be smaller than the other that's how I would tell the difference ??

And the primary side of the carb would be the one with the choke on it??

[Rays74]

haha yeah looking below the float chamber, just above the base of the carb you'll see two 12mm bolt heads. Underneath those sit the main jets......yep the smaller with the choke mechanism :) You'll need a thin screwdriver too get them out of their respective holes and a magnifier to read their sizes stamped along the rim of the jets edges. Careful twisting them out, they're soft brass and can be beat up pretty easily if pumpkin-headed ;) I'm sure Mike will come along with a few keys pics for you, lol.

[Boom death]

haha yeah looking below the float chamber, just above the base of the carb you'll see two 12mm bolt heads. Underneath those sit the main jets......yep the smaller with the choke mechanism :) You'll need a thin screwdriver too get them out of their respective holes and a magnifier to read their sizes stamped along the rim of the jets edges. Careful twisting them out, they're soft brass and can be beat up pretty easily if pumpkin-headed ;) I'm sure Mike will come along with a few keys pics for you, lol.

thanks for the quick responce seems like a pain in the rear to get them out while its still mounted found some diagrams on google or i should say parts list but they are all looking from behind the carb kinda hard to tell i think 69 and 73 are what i need to check right?

[datzenmike]

The jets are just under the bottom of the fuel bowl but you can get to them from the outside. (probably best to remove the carb)

 

Very far right bottom. Below the round sight glass, down to the slotted screw that holds the cover on the fuel bowl. Look just to the left an inch or so along the bottom you can see a hex nut shape. These can be removed to get a screwdriver up inside to remove the jets.

 

 

A little bit better view of both cover plugs , right bottom corner of carb.

 

 

 

Jet size? This is the problem they look identical. The difference is the small hole in the center that the gas is sucked through. You can barely see the difference by eye so they are stamped with tiny numbers around 100 for the primaries and around 150 for the secondaries.

 

[Rays74]

Follow the all knowing Red Arrow, I photo chopped Mike's pic to help ya a little...LOL :) There are two side by side, the diagram you posted is for something else, not sure what?

 

[Boom death]

Thanks guys will be checking them tomorrow hopefully that fixes the issue ...

[ggzilla]

First things first.

 

1.

From your photos, looks like the choke is not fully opening. It must be all the way open, not nearly. Just rotate the housing open. You don't need much choke is socal.

 

2.

the little sight glass with the dot barely shows any gas in their

That's a huge problem. Set the float level is the foundation. Set the float level correctly.

 

The plug hot/cold will clear up once the carburetor mixture is correct.

[Boom death]

Ok so I took my carb out checked the jets Looks like I have a 95 on the primary and a 160 on the secondary... Seems to be normal from the info above .... Float was readjusted and gas level is now right on the dot going to fill it up again and see what it does ??

[ggzilla]

Yep. let us know how it work.

 

You WILL need to adjust the idle air/fuel mixture. It can't be done in the rebuild shop, but must be done the running engine.

[Rays74]

Change those plugs too, ditch those platty's.......NGK's are my choice ...BPR5ES gapped @ .040..BPR6ES are ok too, just a stage colder. (IF using points ign then tighten up the plug gap to .035 :))

[Dat Lurka]

Definitely get some proper NGK plugs.

I put those platinums in my Cutlass and dropped from 33 to 29 mpg.

[Boom death]

Well I got new plugs in and set the idle air mixture don't know is it worked or not waiting till the weekend to take it out on a long trip but it definately drives better now before I could never get my big 245/50/18 to chirp and today she did and it's not as sluggish as it used to be

[ggzilla]

You haz carburetor skils now. Congratulations!

[Boom death]

So I think I've tried everything and this dam stock hitachi carb is still running pig rich fml