Relevant Kits

This article is specific to cycling and jamming issues experienced in fully automatic firing of kits installed into an LCT AK. Some of the solutions may also work for different kits, or for semi automatic cycling problems, but that is not a guarantee. Please see the troubleshooting article that best describes both the kit and the issue(s) you are having.

Symptoms

The two most common symptoms experienced with this issue are:

• The cyclic rate of fire ramps up and down with no apparent pattern
• The bolt carrier jams midway in its travel, and holding the trigger releases a constant stream of air

Racking the bolt may temporarily alleviate the problem, but it reappears no matter what magazine, input pressure, or hop up adjustment you choose or make.

Causes

While some causes are much more likely than others, one of more of the problems on the list below is most likely:

• Unintended friction in the system (bolt carrier binding on receiver rails, outer barrel adapter canted in receiver, etc.)
• Poor magazine compatibility
• Regulator pressure too low
• System timing problem

For issues experienced in full auto only, system timing is the most common culprit. Because the Daytona engine is a fully-mechanical system, cyclic rate of fire and bolt return to battery both become variables in system function.

Rates of fire that are too low may cause an imbalance that results in the bolt jamming in its rearward travel. This is why a build might function perfectly in semi automatic, but experience issues in fully automatic.

Solutions

One or more of the following suggested changes should alleviate the cycling issue in your build:

• Try different magazine brands and types
• Try different BBs if the issue only occurs in live fire situations
• Increase regulator input pressure to 120 PSI
• Install a stiffer recoil spring; OR, if a stiffer spring isn't available, place shims on the recoil spring guide behind the spring to increase its tension. Usually, you will need to place around 3cm in length of shims behind the spring to solve the issue if system timing is the problem

Notes on increasing spring tension:

In addition to potentially solving your cycling issue, increasing spring tension will also:

• Increase cyclic rate (RPS)
• Potentially cause a slight increase in muzzle energy due to the mechanical system (the valve will put more air into the airshaft due to the airshaft staying lined up inside the valve slightly longer). This may mean you need to turn your regulator down slightly to return to your preferred output energy. Results will vary. Test your gun following this fix
• If you increase tension by installing shims behind the spring, keep in mind that if you install too many the airshaft will not travel backwards far enough to feed the next BB.
• Increasing spring tension with shims will also place more stress on the recoil spring, reducing its overall lifespan. Wearing a spring out in this manner is not a warranty issue, and will not be treated as such by DGA

Relevant Links

Having feeding issues? Check this link.