650 special will idle but won't rev, sputters and backfires

[craigrendar]

ok I'm not very good with diagnosing problems so here it is, I'm running a pma with a pamco ignition pwk carbs and open exhaust, I am also running a 650 central minimalist battery.

When I put everything together it started in three kicks but ran poorly so I checked the cam chain tension, valves and timing and its all good. It idles fine but when I try to rev it backfires and wont go past 2. I cleaned the carbs and checked the float levels and its all good but it still didnt work. So i took out the spark plugs and they were jet black so I cleaned them and it ran fine, I took it around the block and then it died. I got back and cleaned the plugs again but it still idles fine but wont rev. I tried experimenting with the timing and the air fuel mixture but nothing seems to help. I also put in a leaner jet and changed the needle one position down and it still runs the same. Please help.

 

[Reid]

Check your battery voltage at idle and while you try to rev it. Mine did the same thing and after 2 batteries, 2 voltage regulators I found that the regulators connector pins were poorly crimped. Pushed them out recrimped and soldered havent had a problem since.

 

[craigrendar]

thanks you were right the battery was no good.

 

[Reid]

Dont forget to check those connectors, I thought I was out of the woods more than once with mine

 

[douglas1kr]

Hey everybody! I was wondering about this same problem. I'm also running a pamco ignition, open air filters and exhaust. I dont have a pma though. I thought you didn't need a battery if your'e running a pma.