Replaced Carb, Can't Get Truck to Start

[sp73]

500 RPM might be a little low. What is your timing set at now?

No idea. This is all new to me.

I attempted to adjust the idle mixture and idle speed screws and my idle is up around 1100 now.

I have 15 inches of vacuum with the choke off and 20 with it pulled out based on readings from the brake booster line. I need to get a tach tool and do this properly, reset the idle mixture screw to default and start anew?

 

[Pighead]

No idea. This is all new to me.

It's good to know your timing number, how many degrees before top dead center your sparkplug starts to fire is important. A tach tool (tachometer) can often be found on a timing light, which is useful. A vacuum gauge is useful as well, I use both when tuning my engine.

 

[bhsdriller]

1,100rpm is too high. Check the below vid to adjust the idle mixture screws
I believe normal idle is ~650rpm

 

[sp73]

1,100rpm is too high. Check the below vid to adjust the idle mixture screws
I believe normal idle is ~650rpm

The video link doesn’t work?

I’ve backed the screw off but it’s not dropping idle.

 

[sp73]

It's good to know your timing number, how many degrees before top dead center your sparkplug starts to fire is important. A tach tool (tachometer) can often be found on a timing light, which is useful. A vacuum gauge is useful as well, I use both when tuning my engine.

Harbor Freight has a timing gun with an RPM function made by Zurich. I might grab that tomorrow.

 

[sp73]

The video link doesn’t work?

I’ve backed the screw off but it’s not dropping idle.

I see the video now. Funny - I bookmarked this just yesterday. Great segment; that shop is about one hour from my house.

 

[Combat Wombat]

try not to bottom out the mixture screw too hard, It is quite easy to damage it and reduce its effective variable flow.

 

[sp73]

try not to bottom out the mixture screw too hard, It is quite easy to damage it and reduce its effective variable flow.

Yes. I did read this and I turned clockwise until I felt tension then backed out two turns.

 

[sp73]

Ok! So last night I bought a timing gun / tach from Harbor Freight. Funny, I am 52 but I've never touched one before.

Anyway for the life of me I could not see markings on the flywheel through the window so I went underneath and pulled the inspection cover and then rolled the truck back a few inches or so until I saw (1) a hole the size of a BB and (2) a line stamped/etched in the flywheel. I used white out on both.

Back up top I started up and with the gun set at 7 degrees I saw the BB was right of the reference line and the etched mark was left of it. After using copious amounts of brake cleaner to find the dizzy clamp bolt I rotated it with the engine running until the reference line and the etched line I marked with white out lined up. My idle came right down to about 650. Magic.

So I will now do the lean drop adjustment and see how that goes. Hopefully what I've accomplished this morning was done correctly.

** Question: There was quite a bit of oil in and on the flywheel inspection cover. My guess is oil pan gasket leak?

 

[Pighead]

I rotated it with the engine running until the reference line and the etched line I marked with white out lined up.

you are making good progress, well done.
But, you may not want to leave the engine timed to the etched line on the flywheel. Traditionally you time to the BB, which is 7 degrees Before the Top Dead Center (etched line). Most engines like this advance, some engines like a little more advance.
Try driving with the timing as is, then adjust timing to the BB ( the idle speed may increase as you do so, just turn out the idle speed screw to get your idle back down to where you like it) and notice the difference in drivability. If it drives better you could even advance the timing a bit more and see how it responds.
Armed with a timing light and vacuum gauge you can begin tuning your engine to where it runs it's best.

 

[sp73]

you are making good progress, well done.
But, you may not want to leave the engine timed to the etched line on the flywheel. Traditionally you time to the BB, which is 7 degrees Before the Top Dead Center (etched line). Most engines like this advance, some engines like a little more advance.
Try driving with the timing as is, then adjust timing to the BB ( the idle speed may increase as you do so, just turn out the idle speed screw to get your idle back down to where you like it) and notice the difference in drivability. If it drives better you could even advance the timing a bit more and see how it responds.
Armed with a timing light and vacuum gauge you can begin tuning your engine to where it runs it's best.

Easy enough to do this later today.