'72 45HP Chrysler

[catcatcher]

This has been a great motor since my Grandad bought it new. The problem I am having with it is when it is at a idel it pumps water fine. At full throttle it doesn't. I checked the impeller and it is fine, the keeper that holds the impeller in place is still there. The head gasket was leaking water from around it and when I pulled the head off the head gasket was trashed so I thought I had found the problem. After replacing the gassket it has the same problem.

On the lower unit there is a hole beside the front bolt hole that I noticed bubbles comming out of when running it in a barrel. I have never noticed them comming from this hole before and was wondering if this could be an indication to what the problem is.

Any advice would be great as I am out of options!

 

[AuSable Junkie]

Re: '72 45HP Chrysler

When you say you checked the impeller, did you remove it from its housing and do a hands on inspection? The reason I ask, is I thought mine was fine because I turned the drive shaft and watched each of the vanes on the impeller as they passed by the "window" in the cover that I could see the impeller through. All the vanes were there, no apparent melting, etc. When I took things apart and held the impeller in my hand, I could see a large tear right where the little pin connects the impeller to the drive shaft. I bought a new one and put it in needless to say.

Without removing the impeller and being able to see the whole thing, I would have still believed it to be in good condition with my un-disassembled inspection.

 

[catcatcher]

Re: '72 45HP Chrysler

Yep I pulled the impeller out and inspected it. It was still soft and no cracks or rips in it. The inner part looked good also with no way for it to slip on the shaft with the keeper in place.