New build :backfires out exhaust violently (pma/pamco e advance)

[Liftedzuki]

So I spray some starting fluid in the cylinder, give it a kick, it nearly breaks your ankle.

The pamco is set middle, the engine internals are untouched. I rewired the whole bike running a little battery.

 

[Capslocker]

Did you put the pin in the camshaft where the old advance unit was?

 

[Liftedzuki]

Yep. Could valves be really far off? I never checked them.

It had good compression but besides that it's the original motor with 15k or something on itt

 

[jd750ace]

Did you verify it even RAN before you started adding stuff?

 

[Liftedzuki]

Nope. It didn't have spark so I figured I'd just go all new electrical (has really good compression and looks good inside) worst case I'd do a rebuild.

I'm fairly confident no one's been into the engine before me.

 

[Kathos]

I like!

 

[Liftedzuki]

Thanks! Hard to see but it's nissan white pearl. Looks pretty sweet in person.

 

[jd750ace]

Set your valves and cam chain adjustment. A good bit of lash can screw you at start-up when your advance is only 10 degrees BTDC.

 

[Liftedzuki]

Did valves, cam chain was perfect already. :/

 

[Kathos]

Have you checked your mixture? If both are backfiring then its something similar between the two cylinders.
Have you vacuum synced your carbs?

 

[Liftedzuki]

I did not mess with carbs besides cleaning.

I'm out of town for work. I'll probably get new plugs and take the carbs off try to figure it out.

Thanks guys

 

[Liftedzuki]

Cleaned the carbs and it will idle with the choke but won't run without the choke and won't Rev up. :/

Thinking about sending someone my carbs or buying bs38s? (mine are 1980 bs34s??)

 

[Kathos]

Have you told me you verified your timing with a timing light yet?

 

[mrkil]

If it runs fine with the choke then I would check mixtures. Sounds like the pilot is not working correctly. If you took the carbs apart to clean them they need to be re set. Unless you indexed them before disassembly. But even if they where I would still retune them as you have no idea what the po has done to them.

Also the timing does need to be done with a light to be sure it's correct as mentioned.

 

[Liftedzuki]

Timing jumps all over with the light?

I tried setting it by guessing, and runs Atleast mildly.

I might send my carbs to a pro to go through?

 

[Terrible1]

Check your timing on the other spark plug wire. Your timing should not jump all over.

If you pamco is not received 12.5 plus volts from the Battery/Capacitor the bike may run, but it will run like crap when throttle is applied.

Check for TDC, then check your timing marks, I know the pamco will allow the bike to run if firing before TDC. Make sure that your in the timing mark F when the bike is running/trying to run/start. This mark F (13-15 degrees should be) .5 inches clockwise from your TDC mark.

If those are BS 34 carbs, turn the idle mixture screws out 3 turns and go from there when the bike is running. Have you re-jetted for the open pipes and pod filters? Im +2 on the Mains, and Pilots to get my bike to run well, and not lean fire.

I feel you may be off on the initial timing. I did the split the middle on my pamco install, and it ran, but didnt run well and would pop.

HTH

 

[Kathos]

You gotta balance getting a steady idle with getting a steady timing reading. I would stop putting so much thought into the carbs. Get it to idle and keep that mind on fixing your timing. Don't guess timing.