Installed a rusty old spark arrestor...

[atc350xer]

in my 90 and it pops and spits when I give it throttle.. it ran like a top before this. Does giving it more back pressure change the timing or points settings, or is it a carb adjustment?

[atc350xer]

nobody?:confused:

[UncleBubbles]

more than likely the old rusty arrestor boosted back pressure.

[Mr_RPM]

yeah, i dont see how it would change timing. make sure thew rusty spark arrester is not clogged from being rusty.

[Dirtcrasher]

Rusty doesn't mean not much unless the guts are plugged up a bit....... Choking it up a bit.............

It's easy for you to check the time the points open and how far. It CAN'T hurt to check it anyhow!? If they open before F", then close them a bit, if they open after "F" then open the gap a bit. Timing lights. test lights and or OHMM-Meters show you the time - at the very least!!

I have no idea what you had before? But once those previous items are checked, read the plug.

Does it flow better now, with this exhaust? you may need to jet it up a bit in ANY or all jets, who knows..............??

If it's back down to a stock exhaust, you may be too rich. You may have cooked and or leaking valves and sloppy guides??

IDK what you previously had for an exhaust, or what the valve condition is. But they're all brothers and sisters and have to get along.... :D The PLUG TELLS ALL!! (unless it's so tired that oil from the rings gets in the combustion chamber); Then, just rebuild it, it won't kill you just see what the piston/rings/valves and compression test show. It's YOUR choice!

IDK if it even ran before?? Did it always get fresh oil and was it kept full?? Whats up, give us a lesson :D

I bet SHORTLINE knows this motor VERY WELL!! Search on ATC90 and one way or another you will find him......... Or find it and PM him.

Pour "AUTOZONE" lends us tools for a few days for 00000, ZILCH!!

[atc350xer]

Thanks for the tips, it ran great til I put it in, maybe I will just take it out and see if it's back to normal... it's not plugged up, just ugly.