FishyWil

I have a 1993 yamaha 130hp. At certain rpm the outboard shakes. I have a stainless prop. No trim tabs. What do I do to stop this.

DOUBLE "D" & LV

There are a few things that can cause this. No one answer. Basically, the problem needs to be found. Is this a new thing happening? Sometimes trash in the carbs will cause improper fuel delivery, therefore causing unballanced combustion in the cylinders. Poor compression, water in the fuel, a bad spark plug, unballanced prop, bent prop shaft, leaking fuel pump, carburetors not synch'd, loose motor, diesel fuel mixed in the gas, and a few more can all cause rough running and vibration. All you can do is start with the basics and narrow it down to the problem. (Compression check, ignition check, visual check of the components, testing) Does the vibration happen at the same point everytime, or does it change when it vibrates? If it changes, it more than likely is due to trash in the carb's.

FishyWil

Sorry not to respond. long trip to DC. and back. It started at first only to shake at low rpm. A quick throttle down and go to get past it. I was out the other day and it was rough and i got it to shake running full out. It started right after taking a large wave. Outboards are new to me so its a learning curve. I do have a small dint in the prop, stainless. Any help.:banghead





Also thanks guys for the great forum...........

DOUBLE "D" & LV

It could be several things. A small nick in the prop won't cause what you are saying. Could be something in the fuel system. It sound like the motor might need to have some plugs and some cleaner run through it, maybe a little tlc.I would still say start with a compression check.Start with something and keep coming back, maybe with some initial info on what is found (plug condition, fuel condition, compression reading, etc.) we can help some more. Kinda hard to narrow it down without a starting point. If you get stuck at some point and need help, give me a call.