[Morin Racing 98]

Originally Posted by HurstBros0 We have had the impellers come loose on the water pump before and cause an issue like this. They will be tight cold. As the engine heats up it starts slipping until no circulation happens. Get you a new impeller from Speedy Bill and if the drive side isn`t welded to the shaft ( early KSE were pressed ) , weld it to the shaft. Since the concrete is on the left side , this would leave less standing water to dissipate heat. Hope this helps.

Thanks Dan, I just might try that. The motor never over-heats so we never really thought it was a pump issue.

[kcarm92]

Dan i one do that also took us 6 or 7 nights to find it also radiators fuel pump mag. lol

[6565]

Originally Posted by HurstBros0 We have had the impellers come loose on the water pump before and cause an issue like this. They will be tight cold. As the engine heats up it starts slipping until no circulation happens. Get you a new impeller from Speedy Bill and if the drive side isn`t welded to the shaft ( early KSE were pressed ) , weld it to the shaft. Since the concrete is on the left side , this would leave less standing water to dissipate heat. Hope this helps.

Just to add to this... I had this happen a few years ago at the end of the year. Motor temp was fine (around 200-220) while racing, but on a yellow or coming off the track, would jump to 240-250. All because no circulation as stated-the cool air going in radiator was enough to keep under control until airflow slowed down.