Which came first, the carb or the distributor?

[Dano64]

Hi.

So my new 64 with a 250 was a little tricky to start. I figure out that the accelerator pump wasn't working properly, but it seems to work ok if I push the gas down more slowly to wet the carb.

I think she's running rich and that the timing or points may be off. I pulled the cap to look around and the rotor/cap had some corrosion. Cleaned that off and went for a drive before futzing with anything else.

It seemed a bit better and I moved on to timing. The timing notches on the balancer are showing up at about the 12 o'clock position and the timing marks that show TDC and advance are at about 2 o'clock....off by inches! So... assuming the balancer is keyed do I have a balancer from the wrong truck? When I get to timing, I think I need to manually find TDC and time from there. ya?

My question is logical sequence of checking points / timing / carb tuning. And I'm a little nervous about that last one so I"m hoping carb is last, logically.

Help appreciated. Photos coming soon.

[TJ's GMC]

Originally Posted by Dano64

Hi.

So my new 64 with a 250 was a little tricky to start. I figure out that the accelerator pump wasn't working properly, but it seems to work ok if I push the gas down more slowly to wet the carb.

I think she's running rich and that the timing or points may be off. I pulled the cap to look around and the rotor/cap had some corrosion. Cleaned that off and went for a drive before futzing with anything else.

It seemed a bit better and I moved on to timing. The timing notches on the balancer are showing up at about the 12 o'clock position and the timing marks that show TDC and advance are at about 2 o'clock....off by inches! So... assuming the balancer is keyed do I have a balancer from the wrong truck? When I get to timing, I think I need to manually find TDC and time from there. ya?

My question is logical sequence of checking points / timing / carb tuning. And I'm a little nervous about that last one so I"m hoping carb is last, logically.

Help appreciated. Photos coming soon.

First thing is first....Need to verify Top Dead Center with the timing marks. Remove the spark plug and manually crank the engine until the piston is at the top....I stick a screw driver down the hole and the piston will push the screw driver back out until it's at tdc. Once at tdc check the mark on the balancer to see if it's at the 0 mark on the timing tab. If it Is then you can move on...if it isn't then it's more than likely time for a new balancer.

If tdc is verified and the balancer is fine, move onto the distributor. Check to make sure that all plug wires are routed correctly: 1-5-3-6-2-4 Check the wires going Clockwise around the dizzy. Also check to make sure that at TDC the rotor is pointing at the number 1 terminal or very close to it. New points and a condenser are cheap insurance. I would get a set. Cleaning will help, but a new set that is gapped correctly will help all the more. Once all that is verified, fire the engine and check timing with a light. I'd say start with 10 degrees initial. From all the reading I've done these engines tend to like more advance. My 292 made the most power at 14 initial. lol

The carb is no doubt due for at least a rebuild. The accelerator pump is shot if you don't see a good squirt of fuel down the throat of the carb every time you hit the throttle. I'd invest in a kit and clean the carb up nicely.

Should make for a good runner! I'd also look into new plugs, wires, coil, cap, rotor as well. Also change the oil if you haven't already. Hope some of this helps.

[Dano64]

Ok... Status update.

TJ; I read your post carefully. Thank you. Still made at least one mistake your notes should have help me avoid and many other mistakes. Posting video as new post. I'm realizing that my experience is mostly NOT related to distributors!

[AZKen]

First of all according to our pages a 230 came out in 64 and the 250 came out in 66. So you must have a motor swap. These questions should maybe be in "Inline" forum.

Get new POINTS!, plugs, wire, rotor and cap as suggested. Set points to .016-.019. Be sure you are in that range. Turn the distributor while engine is running until pulley mark is in correct setting on pointer. Somewhere near 4BTDC or where it runs best. Use a timing light with it reading no. 1 plug. If it runs and not backfiring it's not that far off. Do that and report. I don't like throwing a bunch of parts at it, but these ignition parts are cheap and it gives a good baseline to continue.


You have a stationary timing tab with lines/marks and you have a rotating pulley with one mark. Get the pulley mark to 4-8 BTDC on the timing tab/plate fastened to the front of the motor by turning the Dizzy while motor is running on a timing light.
Vacuum advance hose off of the can and plugged.
A (Advance) on tab means "before", as in 4-8 degrees BTDC B efore T op D ead C enter. The zero is TDC, each mark is 2 deg.
A helper is very nice to have.

Don't start changing too much yet until you have the new tune up parts installed and the timing is per specs. Don't be jumping to conclusions like accel pump and all that. It can be fuel delivery/carb or it can be lots of other things. Which brings up...what is the exact complaint? "Tricky" start? Whatever that means. Rough idle? Won't accelerate out on the road? Give us the exact problem your having and we will tell you what simple test to do.

The baseline tune up will tell a lot.
If the float is right and the bowl stays full, you will get a squirt for starting, if choke is 90% closed in the morning, it will start. If not, you will have to crank to get some fuel in the carb so you can squirt one or two shots.


I keep thinking of things and may repeat, sorry. Also, I do not know your knowledge or experience, so if you know all this, ignore my post. Someone will use it someday. There are I-6 Gurus here who will add or correct me if I am wrong on the setup.