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ContinuousWave: Post-Classic Whalers
Optimax 135 Vibration
|Author||Topic: Optimax 135 Vibration|
posted 08-01-2005 05:44 PM ET (US)
I recently switched from a three blade to four blade prop. When we first pulled away from the dock with the four blade, I immediately noticed a vibration coming from the prop/engine at idle forward speed. The vibration disappears at higher rpms (100+). The in gear foward idle is at 560-580 rpms. AT 650+ rpm, the vibration diminishes significantly. Vibration occurs in both forward and reverse idle.
I took the boat to the dealer today where we put the three blade back on for a test and the vibration was still present.
Prior to switching the three blade, I never had any issues with vibration at this rpm range.
We ended up changing the plugs (the plugs needed changed anyway) to see if there was a bad plug but that didn't solve the problem.
At cruise, there appears to be no issues with vibration. Engine mounts appear to be good. There's no excessive slop or play.
Boat is 180 Dauntless w/ 135 Optimax. 75 hours total.
posted 08-01-2005 07:24 PM ET (US)
Are you using the same Flo Torque hub insert in both props you tested? If it is dirty, or worn, it won't seat evenly into the prop and could cause your problem. Try another hub insert, and make absolutely certain the cavity it mounts into on the prop is clean and free of debris. Also, double check to be sure the thrust washer is installed correctly behind the prop. BillS
posted 08-01-2005 08:28 PM ET (US)
I used the same torque washer that was one the shaft. I didn't remove it when I changed props. I did however use the new, from the box flow torque hub insert.
posted 08-01-2005 10:42 PM ET (US)
Could be the insert is defective, not molded correctly with the prop shaft centered in the piece. I've never heard of it happening, but the first rule of troubleshooting is to step by step Un-do the items that you changed and see if the problem goes away. BillS
posted 08-09-2005 06:20 PM ET (US)
I believe all or most outboards will vibrate a little at low speeds and different trim angles just the nature of the beast. Changing props may have just changed the water flow or trim angle needed to run smooth through the water. You might also look at raising or lowering the motor. Having said that, some OB models and manufacturers seem to mask the vibration better. I might add that different boats have differnet characteristics of water flow resulting in less or more vibration at loser speeds.
posted 08-10-2005 11:35 AM ET (US)
Check for recommended idle (in gear) speed. Below 600 seems too low to me. Check it out and adjust to recommended rpm is necessary. Happy Whalin'... Clark.. Spruce Creek Navy
posted 08-10-2005 03:04 PM ET (US)
Nope, that is normal for an Opti in gear idle speed. BillS
posted 08-10-2005 03:05 PM ET (US)
600 is normal, below that is out of spec as Clark states,
posted 08-10-2005 04:09 PM ET (US)
I had the hub replaced with a new one (under warranty). The forward and reverse idle vibration is still present.
The idle is around 560 to 580. I need to find out if 600 is in fact the correct (to spec) idle speed. If so, then that could be my problem.
posted 08-10-2005 04:25 PM ET (US)
I was told that the forward idle spec for the 135 Optimax is 550 rpm +/- 25.
Someone mentioned 600 rpm. Where did that number come from?
posted 08-10-2005 04:35 PM ET (US)
600 is the speed in the troubleshooting chart i have that came out of a mechanics class coursebook for optis when they first came out in 1997. Go with whatever you have that is more current. BillS
posted 10-25-2005 12:28 AM ET (US)
Check the propshaft for straightness.....if it's out more than .006 this could cause vibration.
Also recommend you switch to the new flowtorque III hub kit...it will smooth out the low speed "clutch chatter" that is expecially annoying with stainless props on these engines as well as 4 strokes.
posted 10-25-2005 02:23 AM ET (US)
Sosmerc, What is "clutch chatter" . Thanks
posted 10-25-2005 12:13 PM ET (US)
It's hard to explain, but I will try. In gear, at a slow idle speed, the weight of a stainless prop accentuates the problem...the prop gets ahead of the clutch and it rattles or bangs when the clutch catches up to the prop.
On some boats it sounds like the gearcase is coming apart!
If you bring up the rpm just a bit, the noise goes away.
If you look at a flowtorque III hub you will see that it is split in the middle and has some "give" to it...to absorb the motion or chatter. Like I said earlier, the problem is especially noticeable with stainless props on 4 strokes, 3 cylinders and L4 Mercs...engines that have a very low idle speed and are not terribly smooth. The flowtorque III does make a significant difference in my opinion.
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