My money is he put the rear bearing in the wrong way.

wrong way don't matter u cant still close up a motor with the stock bearing the wrong way,

Wrong way does matter, the edge rounding on the inner race of the bearing is at one side larger. If the bearing is with the wrong side placed the crankshaft will not go that deep. Yes, probably the rear cover still fits but when mounting the fly wheel you will notice a binding.

ro I pretty much aqgree with everything u say brother your a great man of knowledge but this one you wrong on this one the bearing is the same on both sides, ro how can u have different sides when the inner ring of the bearing floats? plus the bearing is made to come apart u telling me they just think everyone in the world knows that they are doing if they take it apart and would be able to measure what side goes which way no!! it would be in the instructions or every bearing would have arrows or markings showing which side goes which way, but again its a floating ring it cant be...

With normal bearings yes, you are right......

Novarossi bearings have on one side a larger rounding so they can keep a larger rounding in the crankshaft for more strength on that place.

If the bearing is placed with the smaller rounding to the rear the crankshaft will not go all the way in the bearing.

There is no groove on the inner racer how u going to keep it off set? U can't it floats it has wiggle room and again there would be instructions which way it goes I have put it in bout ways it dont make a difference

The only instruction is to face the side that shows the balls to the rear.

exactly but that's because of the racer, and the racer is made to come out and what happens when it comes out the balls fall right out so if it had to go back in a certain way there would be instructions u cant have people guessing which way it goes back without instructions or arrows on it pointing which way to put together...if u said the whole inner ring is wider then the outer bearing ring I would say that could be this way it wouldn't matter which way u put the inner ring in but to say the inner ring is longer on one side when u put it back in that's impossible with out some form of markings or again instructions

Dear Ralph, I said it from my first hand experience my friend. But I should admit I'm not really familiar with his specific engine. But as you know recent nova's have different cutting on front and back of rear bearings, even with naked eyes. If you flip it, you can't close the back plate.

Snuvet75 and Roelof are correct. If you reverse a NR bearing you can’t close the backplate fully. The bearing isn’t symmetrical front/rear.

ok I got the final answer roeolf was actually right when he said nova did make different versions of the bearing, and there is nothing that indicates if it is different some motors got the standard version and some the offset, so if u took it apart your on your own to figure it out....

Or better still go by the parts exploded diagrams on the Novarossi website for the particular engine and order the right part number bearing from the outset then you won't have an issue. You aren't on your own if you follow the information provided by Novarossi which is easily at hand!

that wasn't the point of ordering the right bearing we know that this thread was if u put it in the right way like if u take apart the bearing there is no indication which way to put it back together and they don't tell u it's an offset bearing u get it now??

It is not about the offset, it is about the grinded radius on the edge of the race.

Offset bearings are easy to see.

ok but even the exploded diagram available either online or the copy included in the box shows correct bearing orientation ie balls out the back!.

Also if you are fitting a bearing it means you most probably removed a bearing and so common sense would prevail and you'd put the new bearing in the same orientation as the one you removed. Or is that just me??