Help - Any Yamaha Mechanics Here?

[EDGEWATER]

Just picked up a 2006 Parker 2320 with F225 Yamaha O/B.

Engine runs great except for a vibration that is noticable in the cabin at cruise and under load. Idles smooth and quiet.

I pulled the plugs thinking one might be breaking down. Found one a little sooty and replaced. No improvement.

The engine only has 118 hours on it. Been sitting for a while.

Four stoke motors are new for me. I think it should be much smoother.

Planning a trip to CBBT after Christmas. Want to make sure this thing is in tip top shape.

Should this engine be smooth as silk through the entire operating range?

Thanks -

Chip

 

[DaleH]

Yes, it should be smooth! Also look at the propshaft from the rear, directly behind with OB in neutral. Looking at the countersunk hole centered on the propshaft, spin the prop. That countersunk hole (used to chuck up the shaft in a lathe) should remain concentric to the rotations of the prop. It is possible your propshaft is bent.

I'd bring the rig back to where you bought it pronto ... good luck!

 

[EDGEWATER]

Been reading the posts relative to props and vibration characteristics. Wondering if what I'm experiencing is prop related vibration (pulsations).

I spun the prop while mounted and it seems to be pretty concentric. I'll use a dial indicator to veryify this.

The prop looks fine - no damage - just a little paint worn off the tips of the blades.

How much variation should I expect?

As far as performance - the boat seems to run fine. Hole shot good, cruising god, WOT 42mph (Yamaha gauge) at 6100 rpm - a little high. Conditions 1-1/2' chop 5 mph est. wind.

I've only been out on the boat twice.

 

[DaleH]

It's the propshaft I was more worried about. Even remove the prop so the blades don't distract you. FWIW a good propshop could check the prop balance for you.

 

[EDGEWATER]

I'll do that - Thanks