CFMOTO 650 slip on exhaust popping fix

[paulbin]

This mod doesn't completely fix the problem but does indeed cut down the popping of the exhaust. Mine was so bad that every pop would send out 4 inches of fire which looks cool but not good for the engine or the police around you.

It was my mission to solve this problem as I didn't want to be getting into trouble with the police here in Taiwan. I think what causes the problem on our bikes is there is unwanted air entering the intake somewhere so I went about trying to find it, which I did and it was in plain sight.

On the side of each throttle body there is a rubber hose that comes from the breathing system on the bike, I guess its for emissions etc, so I took off the pipes and put small ball bearings in each side then slid the pipes back on..............hey presto no more flames and no more ear bursting pops.

Like I said this mod helps with popping but doesnt cure it, I still get the odd pop now and again but its alot quieter and less often.

I've included a picture and highlighted the pipe in green.7968525.jpg

[prince666]

Interesting fix ! and thank you for posting. Like to hear what other people have to say

[moilami]

I have about similar thing in carburator tube. A plastic pipe attached from two ends of the pipe into the carburator tube.

By the way, it can be a good idea to crop pictures and put a bigger picture, so that the thing one want to show can be seen well.

[paulbin]

Yea sorry about the picture it was the best one I could find on the internet.

[ZMC888]

That popping is due to excess fuel getting into the pipe. The exhaust change means that the gasses are getting out of the engine far faster than they are designed to, so the fuel not being burnt in the engine but in the pipe can indicate a lean condition. By pulling off some emissions stuff, you've probably helped the bike run richer. Sounds like you'd ideally need and ECU re-map, but I'm not sure that's possible.

If possible I would put your bike on a dyno and check that the bike is running similar to stock torque and hp numbers, are you really gaining any power or torque or are you just running lean, possibly damaging the engine and ruining the fuel economy for a bit of a weight save and better sound? Would you really be better off running stock pipes or another pipe designed specifically for the the bike or at least an ER6?

Also although it is a PITA on these bikes I would do a plug check (get the bike warm then hit the kill switch from 5000 rpm or more then have a look at the color, any white on the electrode and I'd be concerned).

I'm not an expert, it's just my opinion.

[paulbin]

I hear what your saying, I haven't gave the bike a service yet so in a few weeks I plan to do the lot, I will do the 5000rpm trick and check the plugs.

In an ideal work we would all like a remap, I have already messaged Power Commander but they don't list our bikes.

[ZMC888]

A guy in Vietnam did do some kind of remap running a power commander in a piggyback fashion. He said it was only marginally successful and very complex, he was one of those guys that enjoys complex engineering.