Damper water seals on 92' Pro60

[JPJ]

This maybe a dumb question but here it goes. I have a 92' Pro60 tiller.I have had intermittent overheating issues last year. I replaced every component on the water pump with OEM parts. I stiil will get overheating. I replaced the Thermostat too. I went to the parts diagram and noticed that I was missing on the water tube, what is described as Damper water Seal 3. Could this be my problem of not getting the volume and possibly water pressure up to the powerhead causing it to overheat? It has been baffling and frustrating to say the least!

[Inducted]

Yes you need all those seals.