[zaxizax]

Hey guys,

I recorded a video to show this noise if anyone can recognize it.
suzuki VSTROM DL650 engine noise - YouTube

But first here is the story:

This is a follow up post to this one: http://www.stromtrooper.com/dl650-specific-wee-strom/69293-what-happened-my-bike.html

About a week ago on my commute to work my engine started to make a rattling noise and I lost power quickly. (The rattling was there for about 2-3 weeks but very mildly). So I had to tow my bike home.
This Saturday I started working on the bike. I was afraid it was the cam chain. I took both cylinder heads off and to my surprise everything was perfect and neat inside. Nice and clean shiny, no broken chain, no valve problems. I drained the oil, and was surprise to see that about 3/4 quart was in the pan. The oil light was not on when I was riding. I couldn't see the level of the oil on the window correctly, because it had this brown opal stuff on it. I thought it was full. There was no metal particles in the oil. I filled up with 3 quart of Mobil 1 synthetic oil. The engine fired up instantly, giving me a nice idle. But when I gave a little (and more) gas the rattling noise was there.
You can hear on the video.
I took off the Clutch panel, disassembled the clutch plates, everything looked normal and no metal particles anywhere. At this point the day was over, so I though I will ask some help from more skilled strom owners and I will go from there. I will get a new clutch gasket on Monday, but if needed I'll take apart the generator cover too.

Let me know what you think.

A lot of thanks.

 

[Satch]

I'm not tuned in enough to hear the rattle, but what caught my attention was the smokey looking blow out near the base of the cylinder head at about 32 seconds.

 

[redbike72]

Yup, I can hear it at certain RPM.
I've never heard it on my 05.
Is it in the cam chain area?
Have you cut your oil filter apart yet?
At the same time you may want to use a magnet in the oil or strain it for particulates on a piece of cloth.
Oil and filters are relatively cheap diagnostic checks if you compare it to a mechanic who charges 90.00 an hour
I'm Not an expert.
These other guys probably have a better idea of what it is.

 

[zaxizax]

Hey Satch,

Good eye, but it's just a lens flare from the camera lens. I have this video in full HD, I checked it, but it's just a lens effect. There is no smoke whatsoever. Just the noise. But thanks for the observation, I appreciate it.

I'm not tuned in enough to hear the rattle, but what caught my attention was the smokey looking blow out near the base of the cylinder head at about 32 seconds.

 

[zaxizax]

Redbike72: I drained the oil and took off the filter. Didn't cut the filter, I reused it for now, but as soon as I get a new one I'll look inside. No particles, the oil was very nice and clean. I'll check the oil with a magnet.
The cam chain on the top of the cylinder (under the cylinder head) looks perfect, not loose. I checked both cylinders.

Thank you.

Yup, I can hear it at certain RPM.
I've never heard it on my 05.
Is it in the cam chain area?
Have you cut your oil filter apart yet?
At the same time you may want to use a magnet in the oil or strain it for particulates on a piece of cloth.
Oil and filters are relatively cheap diagnostic checks if you compare it to a mechanic who charges 90.00 an hour
I'm Not an expert.
These other guys probably have a better idea of what it is.

 

[Black Lab]

Check the bolts to your subframe members. Mine had worked themselves loose about a year after I purchased my bike, (2007).

The rattling sound does not sound like it is coming from the engine. If you ignore the sound you are speaking about, the motor runs fine. To me, the sound is an "rpm induced" rattle. I believe that something is loose on your bike. I would have guessed it was your skidplate, (because mine does that), but you don't have one mounted on your bike.


B.L.

 

[Black Lab]

Have you cut your oil filter apart yet?

I have heard of other riders doing this.

I assume that this is done with tin snips instead of a hacksaw.

How would you tell the difference between metal particles from the motor, compared to cutting up an oil filter with a hacksaw?

 

[bill l]

I had a Honda SL100 that would seize the piston only when the lights were on. The bike would lose power but idle ok and run great after a few. That was a plugged oil passage caused by me assembling the cam chain tensioner improperly (aluminum particles). I mention this to illustrate that a seized piston doesn't always lock up the motor. 1/2 quart of oil. Yikes.

Bill

 

[greywolf]

I had a Honda SL100 that would seize the piston only when the lights were on..... I mention this to illustrate that a seized piston doesn't always lock up the motor.

You're going to need to explain how that worked. You have a non standard definition of "seized". A seized piston sticks in the cylinder and locks up the engine. The lights would have no effect on oil movement.

 

[Rick505]

I also am no expert but I'd check every fastener/bolt on the bike for looseness. Also sounds like some part rattle/vibration and not directly an engine problem.

 

[kiwi_outdoors]

Ditto

I also am no expert but I'd check every fastener/bolt on the bike for looseness. Also sounds like some part rattle/vibration and not directly an engine problem.

thats what I thought when I heard the video - this is a fun post

most everyone likes a puzzle - well - maybe not the owner

 

[greywolf]

The idea that it isn't an internal engine noise makes sense. I would think an engine problem would cause the noise to be there regardless of speed and the rattle would speed up with rpms. Something loose would rattle when the vibration is within a harmonic range like the recording indicates. It is not present until the rpms reach a specific level and goes away after a higher rpm is reached.

 

[zaxizax]

Thank you guys for all the great advice. Yes, it is a puzzle, and even though I can't use my bike for commuting to work and car transport effectively doubles/triples the commute time to 1-1.5 one way, it's a fun puzzle to me too to find the source of the problem.

But I think it's not just a loose bolt in a non critical part. When this happened I was doing about 100mph and lost power fast. The engine was very weak, and about 5 minutes later I stopped and the engine quit, then I couldn't start it. The starter almost couldn't turn the motor, did about 2-3 slow turns then I quit torturing. I pushed the bike about an hour to my work parking lot, then later towed it home (about 25Miles).

Even if it's a loose bolt it has to be an essential part of the engine. I can see one of the main source is that I had only 1/2-3/4 quart oil in it. I didn't know that, I could not see through the oil window properly. (Now I cleaned it). Also the red light was not on. Sometimes when I was decelerating strong it came on for a sec then went away. (I think that shows that the oil is low, but because the oil window was brown, I though it was full.
I will check all the bolts on the outside. I will get a new clutch gasket next week and do a test run. To my surprise when I filled the bike with 3 quarts of new oil, it started right a way and idling perfect. But as you can hear on the video it sounds bad around 5000 rpm.

So it's a puzzler, but I am not giving up by taking the bike to a shop. Yesterday I went to my dealer here in Venice, CA to get a gasket and to my surprise the went out of business. The nearest dealer now is about 15 Miles away, that would involve towing.
So I will see. I'll post more information and new video as we progress.

Thank you again for all the help.

The idea that it isn't an internal engine noise makes sense. I would think an engine problem would cause the noise to be there regardless of speed and the rattle would speed up with rpms. Something loose would rattle when the vibration is within a harmonic range like the recording indicates. It is not present until the rpms reach a specific level and goes away after a higher rpm is reached.

 

[JRWalker]

sounds like bad crank main bearings to me. g-luck on your fix and ride safe.

 

[greywolf]

Bad crankshaft shells cause a deep bass thunk, not a treble trill. I guess it's possible a camshaft could avoid rattle at very low and very high rpm. Plasti-gauging the cam bearings would tell but, if it is engine related, something like an oil pump would be more likely. A stethoscope to pinpoint the source would help.

 

[redbike72]

I have heard of other riders doing this.

I assume that this is done with tin snips instead of a hacksaw.

How would you tell the difference between metal particles from the motor, compared to cutting up an oil filter with a hacksaw?

Most mechanics have an oil filter cutter in their tool box.
They usually consist of a couple of rollers and a hardened cutting blade. They look like a giant tubing cutter. A good one will leave no debris in the filter pleats of the filter as long as you clean the exterior of the filter before cutting it open.

It's a handy tool if you do diagnostic work. The prices vary but they aren't too expensive as a general rule.
The downside is that they leave the filter can as sharp as a scalpel and your knuckles can take a nasty gash if you get sloppy.

 

[Black Lab]

Most mechanics have an oil filter cutter in their tool box.
They usually consist of a couple of rollers and a hardened cutting blade. They look like a giant tubing cutter. A good one will leave no debris in the filter pleats of the filter as long as you clean the exterior of the filter before cutting it open.

It's a handy tool if you do diagnostic work. The prices vary but they aren't too expensive as a general rule.
The downside is that they leave the filter can as sharp as a scalpel and your knuckles can take a nasty gash if you get sloppy.

Got it! Thanks for the reply. I learned something from it.

 

[bill l]

You're going to need to explain how that worked. You have a non standard definition of "seized". A seized piston sticks in the cylinder and locks up the engine. The lights would have no effect on oil movement.

I am quoting my college instructor in motorcycle mechanics who also worked at the local Honda dealer where I took the bike. He did the diagnosis. There was a clogged oil passage in the head. The extra load from the electrical was enough to overheat the motor and score the piston and cylinder. Truly a straw that broke the camels back if there ever was one. I saw the piston and bore and they were definitely scored but the motor never locked up completely, just lost power. What is the correct term for that?

Bill

 

[greywolf]

Scored is probably as good a word as any. What happened was the lack of oil caused extreme wear on the piston and cylinder. The tiny engine was damaged to the point where the extra load placed on the magneto from turning on the lights was more than the weakened motor could handle.

 

[redbike72]

So in effect, this engine was on the slippery slope to destruction and would have failed on the first long and steep hill.
Does that sum it up?
Any ideas as to what blocked the oil passage?
If the sight glass was covered in brown STUFF, what was the rest of the engine like?