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25 hp Tohatsu 4 sroke knocking in Forward Gear

C

capt_ajax

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"Bought nearly new 2007 engine

"Bought nearly new 2007 engine w/ Alum. prop, removed it and added a SS prop. Noticed when shifted into F, a knock is heard, but unheard when throttled. Checked /changed lower unit fluid, all clean."
 
Tohatsu Rep. and Power-Tech Pr

Tohatsu Rep. and Power-Tech Props confirm the sound of a 'knock' is normal when prop. is changed from alum. to st. steel.
 
"Th additional weight can caus

"Th additional weight can cause a clunk...It seems to be noticeable on aluminum boats, but isn't really noticeable on fiberglass boats."
 
This 25hp is mounted to a Hell

This 25hp is mounted to a Hells Bay f.glass vessel. The 'clunk' sound is audible with engine in Forward - no throttle. But the sound is unheard when throttle is increased.
 
I believe you...I've heard

I believe you...I've heard the noise myself more than once. I run both aluminum and fiberglass boats with the 25/30 and it wasn't an issue on the glass ones and was only irritating on two out of a dozen aluminum ones. Chances are you still have the break-in oil in the lower unit...It's thin. When you replace it with the EP 90 I think you will find it less noticeable...Maybe not as every ones experience is a little different.
 
The lower unit oil has been ch

The lower unit oil has been changed. I'll live with this 'noise' because Tohatsu has assured me this is normal with the st. steel prop. and no damage is being done. Thanks.
 
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