Custom/Hybrid 61x brand new Jetnetics flywheel vibration up to 1/4 throttle

[550headache]

This isn’t in a super jet. It’s in my Yamasaki 550/701/750 pump build. Bought a brand new Jetnetics flywheel and installed it on the 61x when prepping motor to go into ski. This is a new motor to me from a friend. All fresh water, looks like it is brand new on the outside. 150/hole compression. Spins over by hand like butter with no plugs in it.

Got it in the ski and vibrates up to 1/4 throttle. After that it smoothes out and rips! I’m going to pull the Jetnetics off and put the stocker back on and see if it smoothes out.

Everything is aligned properly and the driveline is brand new.

Anyone ever have a wicked vibration form a Jetnetics flywheel before? I’ve owned several but this is the only
‘’New’’ style with the steel center that goes on the crankshaft.

Can i use a 61x flywheel with a 62t mag? I had to switch because the aluminum flywheel was a 62t.

Thanks in advance!


Sent from my iPad using Tapatalk

 

[550headache]

I’m using the mounts RHAAS supplied me with the conversion. Cut that hull gusset by the battery tray. It was hitting. Still had the vibration. I think the couplers weren’t aligned perfectly. I moved the motor around and it looks good now. Need to put the tank back in and try it.
Makes sense about the lighter flywheel. If the couplers don’t solve the problem the stocker is going back on. It sucks that its now got a 62t stator in it and the stocker is 61x. Hate pulling the ebox out and apart!


Sent from my iPad using Tapatalk

 

[Sanoman]

I’m using the mounts RHAAS supplied me with the conversion. Cut that hull gusset by the battery tray. It was hitting. Still had the vibration. I think the couplers weren’t aligned perfectly. I moved the motor around and it looks good now.

Sent from my iPad using Tapatalk

Made me wonder when you said “it looks good now”? What was you alignment process? How much space is between the couplers? What did you do to align it?

 

[550headache]

Used a piece of square stock and feeler gauges. Only could do the top and sides but its all flat. I’m using a OLD rubber dampener.(doesn’t look worn but its 30 years old ish….) Have about a 1/8 inch between the fingers and the flat on the couplers.

The exhaust I’m using is a FPP manifold and a stock kawi 650 SX pipe. The pipe is against the manifold so my next move is to pull it out and do some clearance denting so it gets rid of the rattle! It really sucks the FPP 650sx B-pipe wont fit! It’s brand new only out of the box once!

Sent from my iPad using Tapatalk