[scroggy1984]

I have a 2005 Suzuki Boulevard C50 with about 11k miles on it. The issue started last year (probably not good that I am just now addressing it) and I haven't investigated too much but I wanted to get some ideas of where to start. I don't know how to describe the sound other that a rattle/squeek at the same time. It only happens at cruising RPM (I don't have a tach so i'm not sure what the RPM actually is) and between 60-65mph. It is definitely coming from the engine as it goes away once the RPM's increase or decrease. It sounds perfect at idle and it goes away once I hit about 70-75mph. That being said, I can only guess where the noise is coming from but it is definitely more prominent in the top of the engine area, but it's too hard to tell exactly what/where it is going 65mph down the interstate.


I plan on tearing it apart on Thursday to go through and check things out. I am thinking it may be a valve adjustment issue but I have been told that my bike has self-adjusting valves (though I wasn't told that by a dealer). Has anyone else had this issue or know about it enough to point me in the right direction? I am knowledgeable about motors but more so on the 4-wheeled kind. I assume they work in the same general way but I haven't really tinkered with it enough to be able to diagnose it as well as car motors.

Thanks!

 

[Easy Rider]

I don't know how to describe the sound other that a rattle/squeek at the same time.
It is definitely coming from the engine as it goes away once the RPM's increase or decrease.

Simple vibrations on a bike can drive you NUTS.
What sounds like engine often is NOT.
I think this model is known for gas tank/gas cap rattles.

I strongly encourage you NOT to "tear it apart" until you have investigated easiser and more likely causes.
Others here should be able to provide more specifics.

 

[DrBob]

There are at least a hundred things more likely to be the cause of this than anything in the motor. valve adjustment issues usually present as tapping that gets louder as RPM increases. So the LAST thing you want to do is start 'tearing it apart.'

Cables, hoses, the wire winding around fuel lines, loose bolts, the gas cap vent, loose headlight, loose dash- any of these are know to cause a rattle or chirp through a certain RPM range. Start there, looking for any that rub against anything. Reach out as you drive in the range where you get the noise, then put you hand on different things and see if the noise changed or goes away- a little pressure on the gas cap, headlight, dash, windshield, brake line, clutch, etc, may rapidly lead you to the sourse of the noise. If not, start looking under th tank for anything that is moving or rubbing.

 

[scroggy1984]

Thanks guys! I plan on troubleshooting it more on Thursday so I will definitely take your suggestions into consideration. I have tried to find it with my hand but nothing I can find/reach stops it. I will definitely check all of the rubbers and bolts to make sure they are tight before I think about getting into the engine. Thanks again!

 

[suzukid]

Uh Scroggy, the C-50 does not have hydraulic lifters. They are mechanical and have to be adjusted. I've got the (sob!) bills to prove it. I think your valves need to be adjusted 'cause I had similar sounds the first time I made a round trip to Kansas from L.A. Engine heats up at sustained high speed, parts expand, clearances widen....voila, more noise.....IMHO.

 

[jack87]

Is this the sound you guys are talking about for the valves?

I to am having some noise at about 30500 miles on my 08 Suzuki Boulvard M50. here is a video of the noise its much louder in person and gets worse when on the road. And extremely loud past 30 MPH