RODBOLT help!

flipper 630

Cadet
Joined
Jun 15, 2009
Messages
6
Hi!
I have earlier post about this and then I thougt the noise was from the LU but now I have the LU off the engine and run it at idle without the LU. The noise is a clattering noise (like a diesel) and only at idle under 1000 rpm (worst at 600-700) and only when the engine is warm. When I rewed up the rpm the clack, clack, clack noise dissapear or when the boat was in water i just put the gear in forward or reverse and also then the bad niose dissapear! I`ts only there when the engine is unloaded. After a lot of time spending to figurate what the problem is I now wondering if it could be the timing chain or the tensioner.

Model: Suzuki DF90 year 2006 with 60 hours running time, engine oil fully synthetic SAE 05-40 Shell Helix Ultra.

Otherwise everything is normal, it rews up to 5500 rpm without any problems and the noise is perfect.

Talked whit a lot of mechanicals in Sweden but nobody can help me out!

I hope you have som advice for me!

Thanks in advance!:)
 

rodbolt

Supreme Mariner
Joined
Sep 1, 2003
Messages
20,066
Re: RODBOLT help!

I dont deal much with suzukis but some basic checks may help.
one is the mechanical fuel pump.
they tend to clatter if fuel is restrited or they get air.
the pump will knock just like a collaped hydraulic lifter in an old chevy V8.
pump the fuel primer bulb while its idling and see if the noise diminishes.
 

flipper 630

Cadet
Joined
Jun 15, 2009
Messages
6
Re: RODBOLT help!

Thank you for the answer!

I check the pump today and the clatter was there as you told me, but there is a more deeper clattering sound from the engine in the area where the timing chain is located. And the noise sounds almost the same as from the pump but not that even. Pump noise is like clack...clack...clack...clack...clack and the worrying me sound is clack..... clackeliclack.....clack. tick tickelitic..clack.....clackelicklack.= a bit uneven!
And never when the engine is cold, and never when in gear in water only in neutral. Loaded = no noise and unloaded warm = noise. When I have run the boat for a 10 minutes on high rpm and I slow down to idle and put in neutral the noise is much louder.
I can drive at lowest rpm in gear without the noise but as soon I take the gear out to neutral the noise is back.

Could It be something else inside the powerhead except the chain??????

I hope for more ideas from you.
 

rodbolt

Supreme Mariner
Joined
Sep 1, 2003
Messages
20,066
Re: RODBOLT help!

dunno
like I said I dont deal much with 4 stroke suzukis.
try a call to fridays marine in saluda VA.
 
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