DF250 Intermittent Rattle/Clunk noise

BigNiner19

Petty Officer 1st Class
Joined
Jul 1, 2006
Messages
234
Motor is a 2005 Suzuki DF250 4 Stroke, has always run real good.

Went fishing today. Noticed when we got back closer to the ramp that my motor was just different. Even with the motor in the water, I could hear a little clunk/rattle noise. So when I got home, hooked it up to the hose and just bumped it in and out of forward or reverse to see what I could hear. I included a you tube video, so those with speakers can hear the clunking/rattle I'm talking about.

It DOES NOT rattle or clunk when the throttle is in the NEUTRAL position. But it DOES rattle when in reverse and forward position. Any thoughts or ideas on where to start? I've never heard my motor do this ever before? Prop is not loose.

You Tube Video of the Noise

Suzuki 250 - YouTube

Thanks guys.
 

BigNiner19

Petty Officer 1st Class
Joined
Jul 1, 2006
Messages
234
Re: DF250 Intermittent Rattle/Clunk noise

Okay UPDATE:

For ****s and giggles, because it needed to be done soon anyway. I drained out the old gear lube, and filled with new. The gear lube looked fine, no water, no metals shavings at all. I would like to say I have ruled the lower unit out of this particular problem all the together.

Took the cowling off, did see a little engine oil on top of the intake by the port side breather hose. Not a lot, could have been from tilting the motor maybe? Never seen it there when I've had the cowling off before? May be nothing..just taking note of what I saw.

Anyways...The noise is DEFINITELY coming from the mid-section area. I do not hear the clunking/rattle noise from the top of the motor. I also, do not hear the clunking/rattle noise coming from the lower unit. I put my ear up to the mid-section and could hear and feel the rattle/clunk and can definitely say its coming from the general mid-section area.

Again, no clunking/rattling noise when the motor is running in NEUTRAL. But in both Forward and Reverse, the clunking/rattle noise intermittingly can be heard.

I did not run the motor without the prop, but because I can feel the rattling from the mid-section, I would like to think the prop is not the issue?

Thanks to everyone who has been chiming in. Hopefully I can get this problem solved soon and not spend too much $$$

Thanks
 

99yam40

Fleet Admiral
Joined
Sep 7, 2008
Messages
8,895
Re: DF250 Intermittent Rattle/Clunk noise

Maybe a small miss fire at idle that causes that heavy SS prop and shaft to be jerked back and forth as the shaft speeds up and slows down. Just a thought

Have you done any maintenance to the motor lately that might have changed thing
 

BigNiner19

Petty Officer 1st Class
Joined
Jul 1, 2006
Messages
234
Re: DF250 Intermittent Rattle/Clunk noise

Maybe a small miss fire at idle that causes that heavy SS prop and shaft to be jerked back and forth as the shaft speeds up and slows down. Just a thought

Have you done any maintenance to the motor lately that might have changed thing

Nope, Havent done any maintence besides just last night changing the gear lube to check for metal shavings etc..
 

Inducted

Petty Officer 2nd Class
Joined
Mar 8, 2008
Messages
136
Re: DF250 Intermittent Rattle/Clunk noise

Drop the lower unit, check the drive shaft bushing and see if something came loose. Is it staying in gear? maybe not fully engaged? Just a couple of ideas.
 

BigNiner19

Petty Officer 1st Class
Joined
Jul 1, 2006
Messages
234
Re: DF250 Intermittent Rattle/Clunk noise

Another UPDATE:

Took the advice, and appreciate all input and feedback here. I removed my Mercury Bravo 4 blade prop and ran the motor on the hose without a prop. The Rattle/Clunk/Noise WENT AWAY, and did not make any noises or clunks in forward or reverse what-so-ever.

Regreased and installed 4 blade prop back on, tightening to torque specs (40ftlbs) and the noise came back when running in gear (forward or reverse).

This absolutely tells me that the prop is the culprit for the noise that I am getting. I read online that some say for this to be absolutely normal, and while I typically have never put the motor in gear while running on the hose, the main reason I began to trouble shoot, was because I heard the clunking/rattle noise while the boat was slowly idling up to the boat ramp on a recent trip on the water.

Could there potentially be a loose prop shaft, or a bad bearing or anything of some sort that maybe occurred from me using reverse in the water more than normal (fished in some tight quarters).

I had a buddy able to wobble the prop and essentially replicate the type of rattle/noise that I have been hearing when the motor is running in gear. \

Would like to assure myself that I am not harming my motor or lower unit in any way before I proceed with fishing/boating.

Thanks for all the input and feedback.
 

robert graham

Admiral
Joined
Apr 16, 2009
Messages
6,908
Re: DF250 Intermittent Rattle/Clunk noise

Maybe those wave washers/collar on top of water pump that takes the slop/play out of driveshaft up and down movement during operation?...drop lower unit and check it out....
 

99yam40

Fleet Admiral
Joined
Sep 7, 2008
Messages
8,895
Re: DF250 Intermittent Rattle/Clunk noise

Robert, I am not sure it the Suzuki's have that set up to preload the shaft

Not sure about the large Suzuki's but some other motors do not fire all cylinders at idle so the drive shaft speeds up and slows down as cylinders fire and that causes heavy SS props/shafts to make some noises. Just a thought
 

robert graham

Admiral
Joined
Apr 16, 2009
Messages
6,908
Re: DF250 Intermittent Rattle/Clunk noise

Robert, I am not sure it the Suzuki's have that set up to preload the shaft

Not sure about the large Suzuki's but some other motors do not fire all cylinders at idle so the drive shaft speeds up and slows down as cylinders fire and that causes heavy SS props/shafts to make some noises. Just a thought
I'm not sure either if Suzuki has anything for shaft preload, but just an idea...Maybe best to drop the lower unit to inspect for what's causing that rattle?...
 
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