Xj750 engine swap

I have an XJ650 that I have engine swapped with 750 83 seca then After I connected everything I started it and it idled then it killed itself and I started it again and it red lined as high as they could go it also backfired out of my carbs and killed my battery trying to get it to start after that I now have the battery charged and they idled fine when I tried to start it but it also killed itself again nama most sure that it is the timing but not positive any advice that you guys have will be appreciated thank you for reading

 

Also this motor has 6204 miles on it according to the dealership I bought it from and their environment controlled warehouse I also changed the head gasket and it seemed to be in good condition still my timing cams were also appeared to be in good condition but I didn't touch them only the gasket

 

-What carb rack did you put on?
-Did you check for vacuum leaks?
-did you accidentally swap the cables?
- is your throttle cable sticky?
-is your throttle tube sticky?
-are your vacuum caps on tight?
-did any blow off with the backfire?

how did you not touch the cams if you replaced the head gasket?? You mean the valve cover gasket?

 

The carbs that I put on were often my 650 but The previous owner said that the Carbs were off of a 1100 CC and I Did the valve cover gasket yes with the cams but I did not remove the cams Also I did not check for vacuum leaks I will do that and I am sure that I have everything in the right place

 

My carbs were working fine off of the other Engine but I'm not sure if they are sticking it doesn't seem like that when I had them off I could see the throttle opening and closing inside so I'm not sure

 

So you’re running a 750 with 650 carbs... unlikely that THAT would cause a runaway rpm.

1100 carb rack—— I don’t think it would physically fit your engine

 

OK update I won't even start at all unless I've tapped the starter button would my starter make it run like that If it was bad

 

You’ll have to explain more...none of our bikes start unless we hit the starter button.....