[c50ltdgcp]

My 2005 C50 limited has experienced a cold engine knock since I purchased it at 2,500 miles. It gradually diminishes as the bike warms up, and the knock seems to come from the bottom end area. It has gradually become more pronounced as the miles have accumulated (now 15,000). The bike has been well maintained and has been run on Amzoil synthetic since 5,000 miles and the original owner had the initial service done on schedule. Noise more pronounced under load. I seem to recall that some owners had experienced this noise on C50's also. Does anyone know what the source of the noise is? Appreciate any input.

 

[PhilJet]

Hopefully somebody will chime in here soon for ya. In the meantime, here's a little bump.

 

[jimKo]

c50ltdgcp,
The C50 motor is pretty noisy normally.

I was wondering if you can physically "feel" the knock if you place your hand on the motor?

Usually a slight knock when cold is piston slap.

 

[c50ltdgcp]

engine knock

I placed my hand on the side of the engine while cold and I could not feel anything coinciding with the knocking sound. The noise decreases to being only slightly audible under load at low rpms once the bike has been ridden a few miles. And no, it is not a fuel-related knock, definitely mechanical. I have heard something similar in and older-model Intruder 800 which I believe shares most of the internal engine parts with our bikes.

 

[metzgers3jjl]

I've had the same noise and even more so when cold and under load. Once i get out on the highway and the engines warms it's not as bad. I think Suzuki could have done a better job with bearings but oh well. I use Mobil 1 10W30 and also put some Lucas oil treatment and it seems to help when it's warmer. Someone told me i could try some Slick 50 at my next oil change but wasn't sure i should try it.
My overall solution was 2 inch Cobra Drags so i can't hear a damn thing!!

 

[OTG]

I've had the same noise and even more so when cold and under load. Once i get out on the highway and the engines warms it's not as bad. I think Suzuki could have done a better job with bearings but oh well. I use Mobil 1 10W30 and also put some Lucas oil treatment and it seems to help when it's warmer. Someone told me i could try some Slick 50 at my next oil change but wasn't sure i should try it.
My overall solution was 2 inch Cobra Drags so i can't hear a damn thing!!

I do believe I saw some very strong arguments against putting Slick 50 in the motorcycle, much less anything else. Do a search and see what pops up.

 

[Tx bohemian]

I've had the same noise and even more so when cold and under load.

Mine does the same, more pronounced when cold, under a load. Hasn't gotten any worse with miles. (17,000)