Distributor advance

[Rich Novak]

72 225 omc sterndrive
What effect does to much or to little advance have on RPM.
My problem is engine acts like it is now getting fuel surges .
New fuel pump, rebuilt carb, advance set about 22*
Thanks, Rich

 

[Scott Danforth]

fuel surges are exactly that, fuel surges. my guess is dirt in the carb yet, and the float not set right.

advance is governed off of RPM by weights and springs. too much advance and the motor starts to suffer from pre-ignition. too little advance and your simply low on power.

 

[Rich Novak]

72 225 omc sterndrive
What effect does to much or to little advance have on RPM.
My problem is engine acts like it is now getting fuel surges .
New fuel pump, rebuilt carb, advance set about 22*
Thanks, Rich

Rebuilt carb recent . is 22* advance enough??
It doesn't want to go more than idle
Thanks, Rich

 

[bruceb58]

Rebuilt carb recent . is 22* advance enough??
It doesn't want to go more than idle
Thanks, Rich

I am assuming 22? is your total advance(base plus centrifugal). Total should be closer to 30?. It also is going to make no difference with your problem going past idle.

I would be checking your fuel pump pressure with a gauge, checking compression and verifying your firing order is correct. I am assuming points ignition...did you set dwell with a dwell meter?

 

[Rich Novak]

I am assuming 22? is your total advance(base plus centrifugal). Total should be closer to 30?. It also is going to make no difference with your problem going past idle.

I would be checking your fuel pump pressure with a gauge, checking compression and verifying your firing order is correct. I am assuming points ignition...did you set dwell with a dwell meter?

New fuel pump.electronic conversion of points. Compression good, nwrw heads with valves.
Of advance should be around 30 total I need to increase it.
Why wouldn't effect RPM. ??

 

[bruceb58]

If you can't get past idle, your distributor hasn't even started advancing.

Has your engine ever run correctly since you put in the Pertronix module?

I asked a couple other questions in my previous post.

 

[Scott Danforth]

your distributor will have about 22 degrees of mechanical advance. total advance should be base + mechanical or 8 degrees base + 22 mechanical advance for total of 30 degrees by 2800 RPM

if you cant get past idle you have a fuel problem or some other problem. if you didnt chase each and every passage with a wire and compressed air, its not clean.

 

[gm280]

When you say you can't get beyond idle, why not? Does the engine start breaking up or starts dying, or is there an actual mechanical problem stopping it from moving? Have you verified TDC on number one cylinder is actually TDC with the pointer that you use to set initial timing? :noidea:

 

[Rich Novak]

When you say you can't get beyond idle, why not? Does the engine start breaking up or starts dying, or is there an actual mechanical problem stopping it from moving? Have you verified TDC on number one cylinder is actually TDC with the pointer that you use to set initial timing? :noidea:

When accelerating the engine surges( higt low high low) like it is running out of fuel wants to die. Starts up easily. Timing is dead on 10* #1 on tdc.
The reason I keep going to timing adv is it was gunked up I took it apart and cleaned it now I don't know if I have it set correctly.
I am going to install a fuel pressure gauge today ,read somewhere pressure should be around 3#.
No other mechanical problems that I am aware of to hold it back.
Thanks, Rich

 

[Bondo]

I am going to install a fuel pressure gauge today ,read somewhere pressure should be around 3#.

Ayuh,.... Carbs need 4 to 6 psi,....

 

[gm280]

Rich, you don't have to install a fuel pressure gauge in the system. Just put one on the end of the fuel line that goes to the carb and crank the engine. Even if it starts (with fuel in the carb), you will read the typical pressure and can see what the fuel pump is doing. A real simple quick look. I know this works well because I just did that about a week ago myself on an engine. It read 4lbs steady. So you can figure out if the fuel pump has issues real quick. :noidea: JMHO!

 

[Rich Novak]

Rich, you don't have to install a fuel pressure gauge in the system. Just put one on the end of the fuel line that goes to the carb and crank the engine. Even if it starts (with fuel in the carb), you will read the typical pressure and can see what the fuel pump is doing. A real simple quick look. I know this works well because I just did that about a week ago myself on an engine. It read 4lbs steady. So you can figure out if the fuel pump has issues real quick. :noidea: JMHO!

Thanks, I will try that Tues.

 

[bruceb58]

No, you need it in there while the engine is running. Its not just the fuel pump pressure at idle you are testing, its fuel pump pressure when it needs to be providing more flow.

It may not even be the fuel pump, it may be the anti siphon valve at the tank but you need to measure the pressure while you are trying to run the engine after idle.

 

[Rich Novak]

No, you need it in there while the engine is running. Its not just the fuel pump pressure at idle you are testing, its fuel pump pressure when it needs to be providing more flow.

It may not even be the fuel pump, it may be the anti siphon valve at the tank but you need to measure the pressure while you are trying to run the engine after idle.

Oh ok thanks

 

[Boomyal]

....... it may be the anti siphon valve at the tank......

Bruce, I doubt his 1972 whatever has an anti-siphon valve. My 1975 did not.