Engine vibration normal?

[Slinger204]

I recently had my engine rebuilt for my 1995 wave raider deluxe (62T/701). Everything from top to bottom was gone over, bottom end, new pistons, new jugs, both carbs rebuilt , new plugs, new fuel lines and filter etc..

I put the engine back into the ski this weekend and fired it up. After a few minutes of cranking and getting the lines primed, it fired up but with some significant engine vibration.

Now I’m not experienced with these engines, this is the first one I’ve done so this may be normal, but it seemed like a lot of vibration at idle. I adjusted the Idle screw when the ski was in the water and set it so that it’s just past the stalling point. It wants to go as soon as I press start! Which is a good thing.

Just looking for someone who has experience with these engines to let me know if this vibration is normal or not.

I adjusted the carbs to spec from the Yamaha manual so the settings on the carbs should be correct.

Couple things I thought of might cause this:

- drive shaft coupler - I did put a level on the drive shaft from the motor and the impeller shaft and it is level. Now the coupler is pushed together fairly snug, should there be any room between the engine shaft coupler and the impeller shaft coupler?

- Motor mounts - Possibly the motor mounts are bad? Not sure how to tell.... I also have several metal shims that came with the ski, so maybe I need to add those to the mounts???


This engine is brand new so I haven’t ridden the ski yet because I was concerned about this vibration and I didn’t want to take it out for break in and have something catastrophic happen to the engine, costing me hours of time and more money to fix.

here is a link to a video of the vibration

Anyone know if this is normal ?

Thanks in advance for the advice

 

[badvinny]

Poor alignment can cause that!

 

[Pro-pulsion]

Yeah you need to align the motor without the rubber damper in there first. Push the motor tight to the midshaft coupler and put a small straight edge across the top and both sides of the coupler. You want there to be as little difference as possible. Those shims are nice thing to have readily available, I'm guessing you're going to need them. I would also be questioning those motor mounts, it moves around like a bowl of jello on a gravel tamper. The mounts can get soft after many years of service. My SuperJet mounts were getting like that, you could grab the exhaust head pipe push the engine side to side with minimal resistance. When they get that soft, the engine will thrash around and most likely blow a mount. If you grab the exhaust and try to rock the engine side to side, if it feels soft and jello-y or just seems to have no real resistance to the rocking, then it's time to get new mounts.