1980 gs1000gl popping from carb and exhaust

[thebrandonbeezy]

Picked up another 1000 to mess with and it would only run on starting fluid, but made compression. I dont know the exact compression but enough to blow my fingers off the plug holes. For the sake of seeing if the engine/tranny were any good i pulled my carbs and ignition off of my perfect running 1000g and the bike starts immediately, the problem is that when held at high idle it will pop out of the exhaust and the carbs. I laid my arm across the tops of the carbs to see which ones do it and they all do randomly. Now before you ask i was able to burp the engine over with the original equipment and for tge 2-5 seconds itd run it would do the same popping. Ok so going through the bike every nut and bolt have been touched and almost every plug on the harness has been tampered with. Which is why i swapped my stuff over. The carb boots are newerish soft rubber no cracking so im wondering where to look next to tackle this popping? My thought is possible cam timing? I dont doubt the previous owners been in there... any help would be awesome! Ill post up a pic in a few!

[jprice90]

do you have pods?

[thebrandonbeezy]

Nope, stock air box stock exhaust has a k&n slip in with 117.5 main jets which works perfectly in the 1000g i literally just transferred the entire set up on to the 1000gl

[thebrandonbeezy]

Ohh also i forgot to mention that one time i started it with no air box on the old setup it shot a 6 inch fire ball from the number 1 carb

[2BRacing]

I suggest that you adjust the valve clearances - some may already be below the tighter end of the spec.

[chuck hahn]

Timing and carb syncs will also make it do this.

[thebrandonbeezy]

I dont see why they would need to be syncd though, the carbs were alread fine tuned on my other bike, as for the timing i could see it being a degree or too off at the most but i matched it up identical to how it was on the other bike, it was literally a atraight transfer of parts, i did notice a lot of of noise from the rocker cover so im gonna open that up tonight and see whats what

[chuck hahn]

Well if you think that just because they were correct for the other bikes engine performance they should be ok for this bike ...theres the problem.

[thebrandonbeezy]

Why because the set up on the 2 bikes is identical? Shouldn't be a problem. Literally identical. Why would the tune need to be different. That doesn't make sense. Sorry to be a jerk but i mean yeah if the bikes were different like say his bike had a 4 into 1 or cams or somthing yeah i could believe that but i find it hard to believe that when both bikes match perfectly

[JTGS850GL]

What you don't understand is that you're syncing carbs to the engine. Not just to each other. Every engine has slightly different volumetric efficiency. One cylinder may pull a larger volume of mixture per stroke v/s another cylinder. When syncing the carbs your essentially adjusting for that and making each cylinder work the same amount. That's why a vacuum sync is needed. Moving the carbs from one engine to another does not ensure even efficiency across the bank of cylinders.

[thebrandonbeezy]

I gotcha. Theres something internal that needs to be sorted though, so gonna start with that then work my way up to his carbs