They're not even a bad gimmick as they are now, they're just utterly worthless.
First off the crit buff (as it is now) can be removed, it's pointless. They also need to fire a single projectile that can hit up to 90 meters, and has the same damage drop off as any other weapon up to 180 meters. Rather than instant damage, they should deal 1-2 points of damage over 4 seconds.
They should also have a much higher critical chance and critical damage versus ammunition of any kind. It should be 100% if the target is above a certain heat threshhold as well, provided of course, the target area is unarmored. There will also be one of two secondary effects that will drop off in the same way, see below:
1) If there are heat sinks on the affected area, reduce one heat sink's efficiency by 100% for the duration of the effect. 50% chance of affecting two heat sinks if the target location is unarmored (and has two or more mounted in that slot). Additional hits can affect more heat sinks, capped at three from a single source (6 if the slot is unarmored).
2) Add X heat over those four seconds. X being some arbitrary number decided through playtesting, let's start it at 10. A second hit from the same source would generate 50% less heat, capping at three simultaneous effects at 10, 5 and 2.5 heat generation over four seconds each. May require a cap on how high a target's heat % can go to prevent 'locking' an enemy mech.
'Source' in this case being a single mech, so boating them is not as effective. Though I'll admit a hunchback 4P with 9 flamers would be pretty hilarious since a mech with a low number of heat sinks probably couldn't even keep itself powered up without overheating in the first suggestion.
Diminishing returns may also be required for either example if multiple sources are involved, or the caps can become "from all sources" (for instance two mechs equipped with flamers hitting the same target). Any numbers given are there for the sake of having some base point to start discussions or testing on, rather than set amounts that I've decided are balanced.
EDIT: Fixed some spelling mistakes and cleaned up the grammar a bit.
Edited by Kassatsu, 26 February 2013 - 12:02 AM.