2006 Yamaha 150 XTR knocking noise.

[fishcrazyinfo]

My 2006 Yami 150 is making a knocking noise when it is in forward idle or reverse idle. neutral idle, forward and reverse are smooth. I took off the prop and there is no noise. Return prop and the noise starts. Makes noise in water or on land. Sometimes it doesn't make the noise. I have video but can't upload to this forum. Any ideas?

[99yam40]

probably the load of the prop sounding with the firing of the individual pistons hitting the gears and then unloading again

[TownsendsFJR1300]

On some engines, you can get that annoying knock if when the last WP was installed, the driveshaft was NOT PULLED UP FULLY, and the retainer installed.

That set up simply keeps the shaft from going up and down slightly-knocking.. I suspect that may be your noise-Won't hurt anything..

If it is, to repair is to R&R the LU, pull up on the drive shaft and push that retainer back down(while pulling up on the drive shaft)

[robert graham]

On some engines, you can get that annoying knock if when the last WP was installed, the driveshaft was NOT PULLED UP FULLY, and the retainer installed.

That set up simply keeps the shaft from going up and down slightly-knocking.. I suspect that may be your noise-Won't hurt anything..

If it is, to repair is to R&R the LU, pull up on the drive shaft and push that retainer back down(while pulling up on the drive shaft)

My 2nd on this......was your water pump replaced recently?....

[fishcrazyinfo]

Thank you for your replies. It's been about 500 hours since the waterpump was replaced by a dealer. The sound just started a few weeks ago. I do a lot of slow *****ing with live bait, so I'd like to get it fixed. I'm going to take it to the Yamaha dealer for service. I'll let you know what happens. I really appreciate your help. It's good to go in with a little knowledge.

[99yam40]

probably the load of the prop sounding with the firing of the individual pistons hitting the gears and then unloading again

also heavy SS props seem to be worse that the lighter aluminum ones

[pstephens46]

Thank you for your replies. It's been about 500 hours since the waterpump was replaced by a dealer. The sound just started a few weeks ago. I do a lot of slow *****ing with live bait, so I'd like to get it fixed. I'm going to take it to the Yamaha dealer for service. I'll let you know what happens. I really appreciate your help. It's good to go in with a little knowledge.

500 hours on a water pump could be another issue in the near future. How long ago was it changed?

[fishcrazyinfo]

Water pump was changed a few years ago. The boat sat for a year while the fuel tank was replaced. I hope to take it to the dealer for inspection. Thanks for your help!