I have a 2001 Glastron with a Volvo Penta 5.0 GL with the SX drive. I put the boat in the water last weekend and had no problems. I took it out on Wednesday and it started to overheat on me. I trailered the lower unit and noticed a large amount of weeds blocking the water inlet, I removed as much as I could and tried again but it got hot again. So yesterday I purchased a new impeller and replaced, the old one was in decent shape. Same problem so i pulled the boat out of the water and brought it back to the driveway. I reviewed the Volvo Penta overheat diagnosis pdf and tried all the tests. When I hooked up a hose to the pump inlet and tried to flush it out through the outdrive I removed a large amount of weeds. But when I hooked the hose back up to the muffs and left the inlet hose unconnected I thought I would see good water flow, not the case only a trickle. I tried it going back in forth several times with no luck. So I rigged up a radiator hose connected to the transom side of the oil cooler and I got good flow out of the inlet hose. So I reversed and the same thing. So I hooked the muffs backed up and was barely getting water through the transom. I reversed and I got good flow out the inlet holes on the lower unit. I can't figued out my problem, any thoughts? When on the muffs should I have good flow through the unconnected inlet tubes? Any advice would helpful?
