Re: K75 Misfire/Gratuitous Flames/Terrible Partial Throttle

[2check91]

split into your own thread there 2check91...

I have the same problem as the OP, also with an aftermarket exhaust.. (looks to actually look identical to OP's lol.)
1995 K75 only has 1800 miles....

Didn't drive it with the stock exhaust but it didn't have any backfires with the stock exhaust.

Seems to run great though, just constant backfires every half second no matter whats happening with the throttle lol.

op reference link here...

[Laitch]

Didn't drive it with the stock exhaust but it didn't have any backfires with the stock exhaust.

What are you trying to convey to us with that statement? If something isn't used, it won't give any problems? :giggles

[rbm]

Backfires on the K75 are usually caused by air leakage somewhere within the first 20" of the exhaust.  This could be
- the copper gaskets that seal the headers to the cylinder exhaust ports are not doing their job
- exhaust nuts are loose.
- there is leakage in the joint between the headers and the muffler
- there is a hole somewhere in the headers themselves

Double check all of these potential causes.  Replace the copper gaskets whether you think they need to be or not.  Use a sealant between the headers and muffler or buy one of Bocutter Ed's brass exhaust gaskets

[Martin]

Mine backfired for most of it's life until recently. I could substantially reduce it but never eliminate it entirely. In order of what I did 1/ Adjust TPS.
2/ Adjust mixture. 3/ Keep throttle closed on over run down hills. 4/ Clean injectors and get the injectors to show the correct spray pattern 5/ Eliminated all exhaust leaks courtesy of Bocutter Ed. The only way I can induce a backfire now is by leaving the throttle partially open down hills and even doing that it is extremely rare for it to backfire.

Regards Martin.