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K100-forum.com » Technical, repair and troubleshooting » Engine and transmission » Popping in exhaust

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1Back to top Go down   Popping in exhaust Empty Popping in exhaust on Mon Jan 27, 2020 8:14 pm

Aged speed freak

Aged speed freak
active member
active member
Hi can anyone help I recently got a k75s and I'm noticing a popping similar to a backfire but not that loud when I shut off the throttle going downhill any suggestions or ideas would be very much appreciated then in advance

    

2Back to top Go down   Popping in exhaust Empty Re: Popping in exhaust on Mon Jan 27, 2020 8:17 pm

RicK G

RicK G
VIP
VIP
Quite normal for the K75 try a new gasket on the muffler to header slip joint.


__________________________________________________
"Man sacrifices his health in order to make money.
Then he sacrifices money to recuperate his health.
And then he is so anxious about the future that he does not enjoy the present; the result being that he does not live in the present or the future; he lives as if he is never going to die, and then dies having never really lived."   Dalai Lama


Bikes 1998 K1100 LT, 1993 K75 RT, 1996 K75RT, 1986 K75 GS, 1979 Z1300 Kawasaki
    

3Back to top Go down   Popping in exhaust Empty Re: Popping in exhaust on Mon Jan 27, 2020 8:43 pm

Point-Seven-five

Point-Seven-five
Life time member
Life time member
+1 on the header to silencer gasket.  You might also want to check the adjustment of the throttle position switch(TPS) and make sure the "choke" is fully closing when it's turned off.

You also want to make sure you turn the throttle completely off when coasting.  I know this causes a lot of popping and backfiring because I had a habit of not fully closing the throttle when engine braking.


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Present:
1994 K75RT
1991 K100RS
1988 K100RS SE

Past:
1994 BMW K75S
1992 BMW K100RS
1982 Honda FT500
1979 Honda XR185
1977 Honda XL125
1974 Honda XL125
1972 OSSA Pioneer 250
1968 Kawasaki 175
    

4Back to top Go down   Popping in exhaust Empty Re: Popping in exhaust on Mon Jan 27, 2020 9:54 pm

MartinW

MartinW
Life time member
Life time member
I cured mine after many years of playing around with it, doing the following.
1/Fix all vacuum leaks.
2/Fix all exhaust leaks. Header to muffler can be hard to seal.
3/Adjust the TPS.
4/Adjust the mixture.
5/Make sure that the injectors are clean and have the correct spray pattern.
6/Make sure fast idle is off.
7/ Fully close the throttle on overrun.
You still might get an occasional but very rare backfire, probably because you haven't closed the throttle.
Regards Martin.


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K75s Hybrid
    

5Back to top Go down   Popping in exhaust Empty Re: Popping in exhaust on Mon Jan 27, 2020 10:27 pm

TacKler

TacKler
Life time member
Life time member
I've learned to live with it.  It provides a bit of Kharacter to the S.  Wink


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Red 1991 K75S
    

6Back to top Go down   Popping in exhaust Empty Popping on Tue Jan 28, 2020 3:42 am

daveyson

daveyson
Life time member
Life time member
Prob a long shot but quick check,  which spark plugs are being used,  which leads? Can sometimes be as simple as lose,  dirty or poor leads. Poor leads crossed,  something like that, I don't like them touching.


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11/1985 bmw k100rt (late model)  Vin. 0090567
    

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