Hi everyone,

For the past couple of months I have been monitoring a grinding noise coming from my engine at specific RPM ranges.  I hear it right before I shift from first to second, and second to third, and I presume that it is also present in the higher gears, though the wind drowns it out.  I can also hear it when I decelerate through this same rev range, and it's even more prominent during deceleration. When I open the throttle more and increase the RPMs past this range, the grinding noise stops and the engine sounds fine.  I can best describe the noise as a grinding or growling, akin to what you might hear if you had small metal parts vibrating on a metal table because of some machinery or something.


Over the past two months, since I started hearing the noise, I think it has gotten a little louder, and the range at which I can hear it has increased a bit.  I am placing a video recording of the noise below:

https://www.youtube.com/watch?v=bhfK1riuJ_A&ab_channel=miamikid08sdad

Here's what I've tried so far:

• I thought it might be the cam chain adjuster, but it does not sound like the Boulevard with a separated cam chain adjuster shown in this video: https://www.youtube.com/watch?v=cROjIvHH_Gs&ab_channel=MetricMotorcycleMadness
• I thought it might be a vibrating loose bolt on the engine somewhere, but I checked them and they are snug.
• I've heard that the speedometer assembly can vibrate in the tank and make a noise, but putting my hand on the speedo doesn't affect the noise.

I am hoping that some of you can:

• Help me identify where the noise is coming from,
• Indicate if the noise is a serious matter or just a thing that happens with this motorcycle,
• Offer a solution for how to fix the problem, if it's warranted.

Bike stats:
Year: 2013
Miles: 16k
Cam chain mod: don't think so
White space mod: don't think so
Oil: appropriate level and age
Riding style: nothing too crazy

Thank you for your time!  Please let me know if I can provide any additional information to make your sleuthing easier!  

Have you owned the bike since new?
What kind of oil do you use?
Do you start the bike up and let it idle for long periods while the bike is resting on the side stand?  (Like starting it in the winter to keep the battery charged and the fuel in the carb fresh?)

Dave wrote on 08/26/21 at 03:02:56:


***

Hey Dave, thanks for your response.  

I bought the bike in 2018 and it had 7500 miles then.  I don't think the previous owner did any serious modifications to it.

I use Valvoline 10W40 non-synthetic oil.

I never leave it idling ont he side stand for two long.  Maybe 20 seconds at a time while I run back to close the gate.  Never leave it sitting on the stand to charge or warm up.

You may already have this bookmarked, but here's a link to the cam chain tensioner guide http://suzukisavage.com/cgi-bin/YaBB.pl?board=tech;action=display;num=1191167029.

FWIW, I've had my right side engine cover off twice and was able to reuse the factory gasket, but I would recommend buying one to have on hand just in case.  That way, you're not stuck waiting on it arrive should you need it.  I don't remember if this is mentioned in the guide, but the best thing to do is trace the new gasket onto the top of a cardboard box before you start pulling bolts.  Poke holes everywhere a bolt goes, push each bolt into the appropriate hole, and make notes on the cardboard box next to bolts that are long, short, or have a rubber washer.  Makes reassembly less stressful and confusing.

I need to check out my cam chain tensioner as well and you guys just inspired me to check it out this weekend.

A few thoughts;

- the Valvoline oil you are using as moly. Moly and wet clutches don’t get along.

- the video…I may hear something…but our engines are so mechanicaly noisy it’s hard to tell. If it’s not the cam chain, it could also be a loose nut on the stator, or a loose nut on the clutch basket. You’ll need to determine which side of the engine it’s coming from. Using a wooden dowel as a stethoscope you can narrow it down to the exact location.

- make sure that the engine bolts are properly torqued because they can make a racket. So can a loose heat shield on the exhaust.