I want to remove this and start with a few of the simple airbox and carb mods but I wanted to ask about backfiring and if it's ever even been an issue. I realize what it's there for as I have a honda single and went through the same concerns while uncorking it.

Thanks....Steve

 

I don't think you gain anything performance wise by removing the fire arrestor. However, not having one would be a problem at a OHV park and possibly fire roads patrolled by park rangers.

 

It's there for a good reason or two. But some remove it anyway. A local caught his honda on fire from a backfire with screen removed. In the garage. had to pull seat to put the fire out.

 

I pulled the backfire screen out of 8 eight different 4-stroke singles since the mid-80's. I never had a fire or even a puff of smoke involved in situations involving decel popping, loaded up cylinders, overflowing carbs, or otherwise. In situations where I did the screen removal after doing other mods, in at least half those cases I had to go up one step on the main jet for WOT. If you have plenty of air intake area and a more open exhaust, I think it makes a difference.

 

The risks are low, but not zero.
It's not an apples-to-apples comparison, but my friend's 1968 Norton Atlas caught fire once when he was starting it without a screen in place. We got it extinguished by throwing our jackets over the bike but that was a SCARY moment!

 

Now gc, is it really fair to compare a modern motorcycle's tendency to catch fire with that of a 60's era British motorcycle?

 

Im all about getting rid of useless safety features, kickstand kill switch, clutch safety switch..... but getting rid of a safety feature that would prevent my *** from catching on fire and possibly burn my bike up.... na, i think ill just leave that one in place thanks. I dont care if TNC says hes done it for years on 100 different bikes and never had a problem, all it takes is that one time....

 

Take it out. its a nice frustrating little project with minimal gains on its own, but compounded with all the other free mods, adds up.
If your scoot is backfiring through the airbox then you have some serious issues going on.

 

 

Certainly there are several key differences between that old Atlas and our KLXs, including butterfly valves, electric start, and an air box, all of which will tend to reduce the chances of blow-back.
I have never had a problem myself on any Mikuni-equipped Japanese bike I have removed the screen from either. I suppose the choice comes down to the OP's personal tolerance for risk once he's aware of the risk. Gasoline fires can have deadly and/or lifelong consequences!*