'86 Cobra - Delay Before Impeller Sprays Out, Muffs

[Renken2000Classic]

How long is normal for there to be nothing before water comes out of the port in the housing, after starting on the water hose? I've got like 30sec or so. I could actually hear the impeller when I started it this evening, before it started spraying, and the housing was warm.

It finally started coming out when I brought the idle up from 500 to 1000 or so briefly; it continues at 500rpm after that, but the delay doesn't seem right to me; I don't remember that with my last impeller/housing.

Should I be bringing the idle up to 1000 initially - would that get the water moving more effectively?

I let it run for abt 10min and the temp was just creeping past 180 (more than I've seen running it for that time and more this past week). It was staying down a little under 180 on the hose earlier this week. It runs less than that on the lake. That is, it did; I'm not sure what it will do now.

 

[Renken2000Classic]

So I tried it again after not quite a half hour off, and let RPM around 1000 right away, and there was very little delay. Temp still went over 180 running it at 750rpm-ish.

I pushed it up to 1000 and the temp stabilized and came down to just barely over 180. I tried 1150-1200 with no increase.

I feel like I let my impeller get too hot or something by idling it at 500 right off the bat, maybe earlier in the week (when I first noticed the delay), and especially tonight when I could hear it after it ran for 20 or 30sec during the delay.

Always something with this darn thing. It's time for a new BOAT acronym related to, it never gives you any appreciable length of peace, lol. Let's see... Broke Olmost All the Time. I'll keep tryin' lol.

 

[itsathepete]

I always squeeze or clamp the muffs to force water up to the impeller until it starts to pump. When in the water, the impeller is submerged. Not the case running on muffs.

 

[Renken2000Classic]

I thought the water pressure did that. There's a little getting out, and it's coming out the 2 holes on the RH side, but they fit pretty snug.

I'm wondering what the barb on the impeller housing is intended to be hooked to now. The old housing just had a hole, the new style has a plastic barb for tubing or something.

 

[itsathepete]

I thought the water pressure did that. There's a little getting out, and it's coming out the 2 holes on the RH side, but they fit pretty snug.

I'm wondering what the barb on the impeller housing is intended to be hooked to now. The old housing just had a hole, the new style has a plastic barb for tubing or something.

The water pressure is supposed to but a lot leaks out so you have to turn it all the way up and I like to help it along. The barb/hole is supposed to let air out so it primes easily.

 

[Renken2000Classic]

I pulled the impeller and it looked fine, other than just a little black debris below the cup where it rests on the housing inside. Couldn't tell if it was just a little bit of melted plastic or what.

Went ahead and replaced it and saved the old one. After backflushing the hose to the t-stat to see if there was resistance, maybe in the PS cooler (wasn't).

Had it on the water today, and it ran fine - below the midway point of 120 and 180F early on, and eventually settled in at just above the midway point. That was with low, mid, and high RPM. So I'm pleased with it.

I think learned something about running it on the hose (get the RPMs up to 1000 or so right away until water's coming out the impeller housing, even if the boat runs good and will idle low right off the bat when cold. Maybe that'll help somebody else too