Also! Since your going through impellers, are you checking your oil cooler for the missing vanes? If it is corked up, I have a hunch that can reduce impeller life also. Ask me how I know!

You have blockage some where else in the system, you need to pull the all the hoses off and check for impeller parts, from the power steering cooler forward to the oil cooler, if the system is all free of debris there's no reason you cant run it on a hose, just don't rev it up

That set of muffs BUP is recommending are sweet and are avail through Amazon for $27 plus shipping

Thanx for all the replies.

I usually don't lube the impeller but I did today to see if it made a difference, 3M silicone paste.
I am using Merc parts, not cheap aftermarket stuff.
I have changed the impellor housing before but did not have a new one today

I believe I am not getting the initial prime for some reason. I am not getting water flow out of the exhaust right away nor does the muff seal to the drive housing.
There is water blowing by the muffs
I have previously cleaned any impellor debris from the rest of the hoses.
I also put a diagram in my tool kit for the correct hose connections to the impellor housing, got that backwards once before as well.

I am going to pick up the Merc muffs and a new impellor and housing and try again.
If I have any further issues, I think I'll put a tee in the inlet hose and put a hose connection there. That should eliminate prime issues.
What about putting a check valve on the inlet hose to prevent it draining after shut down.

There is no pump in the drive housing right???

I think Alpha drives have one

No pump in the drive.

I'd not put a check in the suction hose, would just add to net pump head. Tie directly into pump suction, that pump was never intended to draw head.

See the pictures of the new and old impeller.

http://rinkerboats.vanillaforums.com...mp-water-arrgg.

^^^^ He does not have this set up as that is the GEN VII water pump and housing. On that system ^^^^ Merc had a 2 year run of impellers that was not speced to size correctly - hence most of your no prime problems at that timeframe. Those housing GEN VII scar very easily to cause no prime issues or overheat at full throttle as well. Again he does not have this set up.

If you what to see if your impeller is pumping water - take the outlet hose off from the impeller housing at whatever point throw a that in a bucket - start engine with water supply - see if bucket fills with water for max 15 seconds of running only. This is call water output volume test or does the freakin impeller pump water test. Clear hoses thru different sections of the cooling paths is another great test also plus you can see where water is not flowing properly or has a lot of air bubbles in it. U do not what air bubbles in cooling water flow. Some to very few you can not help.

I would install new impeller and housing, dunk the drives and fire the engines. Eliminates some variables.

Any chance that you have a dual water pickup lower? If so, you need to throw a piece of tape over the lower holes to keep it from sucking air there.

You should have water leaking past the muffs until you fire the engine. Then it should suck all the water that you can put to it with a hose.

Last year when some dumbazz {me} put the inlet hose on the bottom of the pump. All the water in the pump then would drain out when engine was shut down and boat lifted out of the water, then would spin dry when first started. Lasted about 3 starts before being destroyed.