L18 carb spitting fuel.

[74green]

Carb spits fuel out of the top.

 

Tried an inline fuel regulator with 2 different mechanical fuel pumps that work with no change. I adjusted the float every which way, I am stumped and hoping one of you will throw me a bone so I can get this figured out before I possibly waste my money on anything.

 

I even custom adapted a single barrel carburetor from an old school chevy inline 6 to see what would happen and it did the same thing as the stock datsun one. I can post pics if desired it looks pretty funny, definitely redneck engineering lol.

 

Truck is a 74 620. I posted about this issue almost a year ago and then I gave up and haven't touched it since. Sad cause it has a new to me motor, brand new clutch that's never been used, and a bunch of other new parts. If I can get the darn thing running proper you guys can expect a build thread on it as soon as I get my rock crawler done and out of the shop.

 

[Skib]

backfire/spitting out the intake is almost always a sign of your timing being to advanced.

[DISLEXICDIME]

x2

[ggzilla]

Yes, backfire and spitting.

 

But fuel running out means the float needs adjusting. Or maybe the fuel pressure is too high.

[datzenmike]

Your plug wires are mixed up, probably 2 and 3 the most common. Find the #! and it goes 1342 counter clockwise.

 

Guess I should have asked a few questions...

 

 

Has this motor ever run?

If so did this just start happening?

Have you done anything to it lately, replaced something, adjusted something

 

 

 

If never been running, have you set the valve lash?

[datsunaholic]

Not to mention "new to him" engine... no guarantee the CAM timing is right. Having intake valves open on compression stroke would certainly blow fuel back out the carb. Lots of things could be wrong. Gotta take 'em one at a time.

[74green]

The guy I purchased the motor from said that it was from a running truck that he swapped a KA motor into. The plug wires are correct, I have not messed with the valve lash as I thought these valves were not adjustable from looking at them but I'm a toyota dummy.

 

The motor runs and sounds ok but "spritses" gas out of the carb and with throttle applied bogs out.

 

Thanks everyone for the replies, I think those who said it is a timing issue are on to something. When I first put the motor in a friend did the timing and it wouldn't run, then I gave it a shot and it runs but with said issues. My neighbor's a mechanic, I talked to him and he said he would go through it and make sure that the timing is correct for $150.

 

I'm a noob when it comes to datsuns and lack experience when it comes to troubleshooting engine problems, my favorite work is welding and suspension modifications. All suggestions are VERY much appreciated.

 

I'm hoping she will purr like a kitten after someone who knows what they are doing does the timing, then I can contribute something constructive! Plans are titan 18's, static drop, toyota bench seat, and a narrowed toyota 8" rear axle with a welded diff.

 

I know this is a datsun forum but I'm attaching a pic of my crawler I built from the frame up to show I'm not a complete retard. ALL work done by me aside from setting up the differentials. W56, Dual t cases w/ 4.7's in the rear, flat belly, chevy 63" rears, custom rear pack up front, high steer, lockers front and rear, etc etc. Literally everything but the motor completely redone and upgraded.

 

[Skib]

make sure cam timing is correct for starters then.

 

where exactly are you located?

 

in my experience most mechanics that are not datto heads

are going to miss the little things because there not used to them.

 

im sure someone around here can lend a hand.

im more than willing depending on location.

[herculesinwyoming]

I Can say for sure even a good mechanic will be thrown by the datsun Quirks.

[datzenmike]

I Can say for sure that $150 to set the timing is $130 too much.

 

fixed.

 

If you know Toyotas then you know how to work on them. If you can work on them you can work on a Datsun.

 

Set L valve adjustment http://community.ratsun.net/topic/16539-l-series-valve-adjustment/ You can set cold to get it going and check when hot.

 

Get the timing checked/set (but not for $150)

[DISLEXICDIME]

150 to check timing that crazy talk

 

check the manual

http://olddatsuns.com/

[74green]

I didn't think $150 to set the timing right was that bad. I forgot to tell you guys that the timing marks are not correct. When I set it I just did the old screwdriver in the spark plug holes method and followed the book, I must have done something wrong.

[ggzilla]

Should take 15 minutes to set the timing. That's $600 per hour! If he had to determine TDC without markings, it should still take less than one hour, or less than $100.

[DISLEXICDIME]

why are the marks not correct?

[banzai510(hainz)]

74green

You should be on Ratsun 1st before swapping all that bullshit.

 

olddatsuns.com

If you till have points

could be a bad condensor also on distributor or worn bushing cause point to open up when not needed.

 

did you swap anything? like a different coil or soemthing?

[74green]

started working on this thing again. any datsun guys in washington state, kitsap county area want to lend a hand? i've got beer, food, and gas money.

 

i'm still totally stumped. i pulled the dizzy, oil pump, and valve cover. got her at TDC on the compression stroke. put it all back together by the book. started right up, and she doesn't bog down as much with throttle now but still spits up fuel.

 

about ready to give up.  :confused:

[datzenmike]

Spits fuel: plug wires mixed up , usually 2 and 3 swapped because rotor turns counter clockwise 1342.

 

Burnt intake or intake valve valve clearance too tight.