Outboard shakes - timing off?

[CaneCutter79]

1979 Evinrude V4 85hp - Motor Break in Trials - YouTube

My outboard has a case of the shakes. In the video above, you will see the outboard shaking slightly while idling. Then later as I rev the motor a little to show a quick throttle response, the outboard shakes even more. My main concern is that the outboard is shaking while on plane. I don't recall my motor ever shaking Ike that. I also do not see other outboards of my model and year shaking on other videos on Youtube so this doesn't appear to be normal.

Does anyone have any ideas or things I can check?

 

[Joe Reeves]

Re: Outboard shakes - timing off?

Normally when a engine shakes, it is caused by the lower splines of the steering arm having stripped out. This is what keeps the lower motor mount bracket in place. When it strips, it allows the lower mount to swivel back and forth on the bottom of the steering tube. If this is the case, you'll be able to grab the back potion of the lower unit around the cavitation plate area and shake the engine violently.

This problem is usually confused with a broken motor mount, causing much confusion when the owner fiinds that the mounts are fine.

Hopefully this is not your problem as it's a real pain to replace that steering bracket.... but unfortunately, it's the most common cause of engine shaking.

 

[CaneCutter79]

Re: Outboard shakes - timing off?

I checked for the splines. They are tight. Seems like slack in the steering cables or connections.

Motor shimmies when idling. You will see this in the video posted above. That's why I asked about timing adjustment. I was told its at 6 degrees retarded which is the correct setting.

 

[Joe Reeves]

Re: Outboard shakes - timing off?

The idle cam timing must be exact.

The specified timing (5 degrees before TDC) should be set when the scribe mark on the metal cam is dead center with the throttle cam roller.

 

[coolbri70]

Re: Outboard shakes - timing off?

I have the same motor, just watched i video of mine too, as i couldn't remember if mine did that, it doesn't.View attachment 182554View attachment 182555View attachment 182556 is your steering like mine? are the linkage connections tight?

 

[CaneCutter79]

Re: Outboard shakes - timing off?

Thanks Joe. I'm going to take the boat back to my mechanic. He's 4hrs away but I know now there are some adjustments and things that need to take place. I think the timing is off a little.

Did you see the video and how it jumps when idling or throttling up at the end of the video?

I haven't checked the linkages yet but assume they are tight. I will have to trace the slack between the linkages and the steering wheel.

 

[CaneCutter79]

Re: Outboard shakes - timing off?

Here is a video of a motor like mine (same powerhead essentially) and when the motor is reved, it doesn't "skip" or sound funny like mine does when the motor is reved up and then winds down. Mine skips on the down side of the rev....

Youtube User's Video
Evinrude Starflite 85 first start of the year - YouTube

My Motor's Video
1979 Evinrude V4 85hp - Motor Break in Trials - YouTube

Does anyone agree with this assesment?

I'm definately going to have the timing checked by my mechanic just to be sure it's still good. I know he's been a mechanic for 25+yrs but I have about 3-4hrs on a break-in after a complete rebuild including a new re-sleeved cylinder and all new pistons. I just want to make sure everything is right and that the timing is not off.

As for the linkages, yes they are just like yours coolbri70. Weather is keeping me from checking the linkages but I hope to do that today or tomorrow. I may have some slack in the cables that allows the motor to shake.

What concerns me most is how much the engine shakes while on-plane and at near WOT. I don't recall it ever doing this before so that's why I suspect the timing to be off slightly. I could see cable slack causing this too however.

 

[BonairII]

Re: Outboard shakes - timing off?

Thanks Joe. I'm going to take the boat back to my mechanic. He's 4hrs away but I know now there are some adjustments and things that need to take place. I think the timing is off a little.

Did you see the video and how it jumps when idling or throttling up at the end of the video?

I haven't checked the linkages yet but assume they are tight. I will have to trace the slack between the linkages and the steering wheel.

An 8hr round trip to have your mechanic tweak the timing? Do it yourself. Worse case, have a local guy do it....it's pretty simple.

 

[CaneCutter79]

Re: Outboard shakes - timing off?

An 8hr round trip to have your mechanic tweak the timing? Do it yourself. Worse case, have a local guy do it....it's pretty simple.

I agree but I am having some other issues as well so I will knock all of them out in one trip. If it's just checking the time, I have a local guy down the road that can do that easy enough. Even for a second opinion....

 

[CaneCutter79]

Re: Outboard shakes - timing off?

Here is a video of a motor like mine (same powerhead essentially) and when the motor is reved, it doesn't "skip" or sound funny like mine does when the motor is reved up and then winds down. Mine skips on the down side of the rev....

Youtube User's Video
Evinrude Starflite 85 first start of the year - YouTube

My Motor's Video
1979 Evinrude V4 85hp - Motor Break in Trials - YouTube

Does anyone agree with this assesment?

I'm definately going to have the timing checked by my mechanic just to be sure it's still good. I know he's been a mechanic for 25+yrs but I have about 3-4hrs on a break-in after a complete rebuild including a new re-sleeved cylinder and all new pistons. I just want to make sure everything is right and that the timing is not off.

As for the linkages, yes they are just like yours coolbri70. Weather is keeping me from checking the linkages but I hope to do that today or tomorrow. I may have some slack in the cables that allows the motor to shake.

What concerns me most is how much the engine shakes while on-plane and at near WOT. I don't recall it ever doing this before so that's why I suspect the timing to be off slightly. I could see cable slack causing this too however.

Back to my original question........
Does my motor shaking or firing inconsistenly seem normal? I don't hear a firing issue but when the motor is winding down, it shakes quite a bit and the timing sounds off a little.

 

[coolbri70]

Re: Outboard shakes - timing off?

this is mine running, all the shaking is me

:facepalm: same motor though

 

[CaneCutter79]

Re: Outboard shakes - timing off?

I think I may have found my problem. shaft was about 18 shaft was about 1/8 inch loose!! Both bolts were loose. I tightened up the bolts and now I only have a little play in the steering components.

I will check more next time I'm on the water.