How much crank play in a 99 is OK?

[funmachines]

How much play of the crank (axial and radial) is acceptable with a 99 200 motor? Is it different with the 06 motors? The 99 200 motor of my son's bike has a lot of play in and out and my 06 300 has none. Are there differences with the bearings that account for the differences?

I'm getting a lot more vibration from the 200 than it had previously so I think I'm going to have to split the cases anyway to find out what is wrong.

Thanks

[mconnell]

I usually check the connecting rod by this simple method:
1. Pull the cylinder and put the motor at top dead center.
2. Hold the rod at the base right above the crank halves and see if there is any up and down play at all. If you can feel play, it's toast.

I don't worry too much about side to side play. It is the up and down that means it is worn out.

Cooksey Crank in Texas will do a fantastic job of rebuilding your crank. I can vouch for Andrew's work. We were college roommates in engineering school. He is very talented.

[Jakobi]

Originally Posted by mconnell

I usually check the connecting rod by this simple method:
1. Pull the cylinder and put the motor at top dead center.
2. Hold the rod at the base right above the crank halves and see if there is any up and down play at all. If you can feel play, it's toast.

I don't worry too much about side to side play. It is the up and down that means it is worn out.

Cooksey Crank in Texas will do a fantastic job of rebuilding your crank. I can vouch for Andrew's work. We were college roommates in engineering school. He is very talented.

I think they were actually asking about play in the crank itself. IE main bearings, as opposed to the rod/big end.

Now, I don't have a whole lot of experience with the older engines but from what I read they used a 2 piece roller on the stator side which always had a bit of clearance/play detectable. I can't recall which way or how much was acceptable, but I think that up to the 07 models they used the same design. I think you may have answered your own question though. A 99 model is getting on some. A 200 usually works harder than a 300, and the excess vibes is also saying something. Might be rebuild time.

[Leo]

Up and down > Bad
In and out > Not so bad.

[funmachines]

Thanks for the help. I'll pull off the stator cover and see how much up and down. This bike had the bottom end rebuilt before and it seemed pretty solid up until the last time I started it up. Maybe there is something else that came loose ( I can hope!), but if I don't find anything I'll pull the motor.

[funmachines]

Another question about crank play - has anyone added shims to tighten it up a bit on these older motors? I measured about .045 in side to side. If I added a .020 or .025 shim it would reduce the side to side movement.

Thanks

[bowhunter007]

Originally Posted by funmachines

Another question about crank play - has anyone added shims to tighten it up a bit on these older motors? I measured about .045 in side to side. If I added a .020 or .025 shim it would reduce the side to side movement.

Thanks

Personally, I wouldn't shim it. If it's worn out, it's worn out...or not.

[funmachines]

I should mention the measurement is with brand new bearings installed in the case halves (with the case halves split) vs the width of the crank. Nothing is worn - this is just the amount of play it has as manufactured. It just seems loose to me based on other motors I've rebuilt. I figured since I'm going to re-assemble the bottom end I could buy or make a shim.

[funmachines]

I decided to add some shims behind one of the bearings. McMaster has 68 mm OD x 55 mm ID shims. I ordered some and I'll install one behind one of the bearings and cut down the slop by at least 1/2. I'll trash a bearing doing it, but I don't like how much it slops back and forth. Bearings are not that much, although it's not as easy to find the Koyo 63/28's.