Haven't tried it but I will

Any danger with reding this engine to 4600 in neutral?

The first thing you need to do is make sure the tach is reading correctly!!

You also really need to make some calls and find out what camshaft was used!! What ever the max rpm is for the cam is what I would shoot for in propping the boat or atleast within 200rpm's anyway..EI. if the max is 5400 for the cam prop the boat at 5200.. If you know for sure that the stock camshaft was used then prop the boat at 4800!!

Was this a Mag engine? I know that they can turn 5000 easily, if it was the 330hp I think those were 4800 maybe 4600 not positive..

I would see if anyone could loan you a 21 mirage stick it on and see if the rpm's change if they don't it's a good indication that the tach needs replaced!!!

im having a 21p mirage plus shipped to me on monday. when it comes your more than welcome to try it out one day when im not out. im on the east side of cincinnati

Thanks I would really appreciate it. I'm on the east side as well live in Anderson and boat is at rivertowne

thats cool!!!! Can't wait to see how the 21 works out!!