If I have a RB that has a high pass catch rating does it get affected by putting him in the WR spot in a 5WR formation?

His RB rating is 63 but when placed in the WR spot it is reduced to 29.

The important # is the potential. Whenever you switch a player to a new position, their overall will drop significantly because they have next to no experience at that new position. As they learn it, their overall will go up. Also worth noting is that the RB's weight is likely higher than the 'ideal' for a WR, which will reduce his overall score as well.

I'm not actually changing his position, just want to use him in a 5WR formation since his pass catching is a 90 and route running is 75. But does putting him in that position reduce the 90 and 75 or is it just his position experience?

No, the 90 and 75 will remain. He will take a hit because of position experience, but that is all. I would expect it to work well enough to give it a shot.

Thanks all

NFL teams do it pretty often (I can think of like darren sproles and other similar backs) it's a good idea imo

That was my thought as well

I play People out of position a lot..like a Speedy,Strong Pass Blocking TE at LT or RT..Never seemed to have an issue. on the contrary he does well!