beerock

at certain throttle positions I can hear my motor making a popping sound.....

is this from being to lean or to rich?

to much advance or to much retard???????

when it does pop it slows down and then goes again...

anyone have a clue?

now that I have my water problem solved its time to work on this......

its not that bad, but it is surely annoying....
I dont like to hear popping sounds.....

im running a 75ocfm carb on a 351w

I have a jetting kit too...anyone got any ideas?

beerock

heres some visualization for ya...

Budman

If it is a Merc Alpha 1 or an OMC That uses the intermittent kill switch (momentarily cuts juice to the ignition to allow for smoother shifting) I would start there. I had an OMC with this problem once. Sometimes it just needs to be adjusted - in my case the torque of the engine was bending the switch bracket slightly against the lower shift cable, allowing the switch to make momentary contact at high speeds. Another thing to check is your ignition timing. I have seen engines pop throught the exhaust or carb when the timing is too far retarded.

beerock

ya I think its the timing too...

my sig says the drive I have....my motor does sort of rev up fast in neutral, but when its in gear and I do it it POPS loudly through the carb....

so if its in gear and i hit the throttle abruptly i hear PAP!
I was lead to believe this was form to much advance?

I guess its form to much retard?
I guess im a retard

ill play with the timign a bit, but my motor is already hitting 5300 rpms

I really dont want to advance it mroe so I can hit 5500-5700 rpms and maybe get a couple MPH out of it

heh, I better be careful with my stock ford valvetrain....

mopower

If the igntion all checks out ok , do a compression check. Burned intake valve can cause this. Also worn or wiped exhaust lobe on your cam. Compression test should show something different . I wiped an exhaust lobe and had the same indication

beerock

you know, I didnt want to think abotu that but my motor does sound a bit weird on the port side......

how do you burn a intake valve?

and how do you wipe out an exhaust lobe?

thanks for any info in advance

jdnca1

Only problem is....its a FORD

beerock

thanks for pointing out my problem....

I beleive this is the technical Q&A forum not the BADGER FORUM

David

If you open the throttle quickly in gear, and you get a pop (backfire) thru the carb, I would suspect the accelerator pump. But if you are getting similar symptoms while running, I would look for a vacuum leak. Do a compression test/leakdown test to make you don't have a cam lobe going away or a broken/ bent pushrod. Are your heads older style or newer style rocker arm studs? Your distibutor cap looks automotive. Check for corrosion at the terminals.
What carb? 750 may be a bit big for that motor.
I looked at your pics closely and see you have an AFB (Edelbrock). Is the secondary air valve working correctly? Where is the hose from the rear of the carb going? Do you have a PCV valve in the valve cover or a wide open fitting with no orifice? Your fuel line and inline filter may be undersized or restricted.
OK I'm getting a headache from thinking too much!

beerock

That hose is from the top of the holley fuel pump and goes into the intake(incase the fuel pump blows),

I have a pcv valve on my valve cover with a ball...

the heads are 1975 rebuilt heads??-is tthere some sort of a difference? I think there older style, the block is a 1975 as well.

the carb doesnt have vaccum secondaries it is a manual secondary......I gained 1 mph buy using the 750 cfm carb....from a 600cfm

here are some more symptoms....

after a nice ride on plane when I slow down(FOR A NO WAKE ZONE) the rpms go down and then back up to the regular rpm's it does this for a couple minutes then goes back to normal idling.

and then theres the abrupt throttle causes that PAP noise I said before....

and the high rpm pop........

timing??????

I dont think its my carbI hope its not a burned intake valve....

how do you burn a intake valve?

by the way this motor is fairly new, 46 hours on her....