70 Chrysler 9.9 cooling problems

[fincherjon@yahoo.com]

I have recently aquired a 14' sears jon boat and a 70 chrysler 9.9. This is my first boat and knew nothing about the engine but to my surprise she fired right up after sitting who knows how long. After the third run on the water I noticed it's not pumping water at half+ throttle, I heard it start losing suction so I idled back. It pumps water fine at idle. I dropped the lower unit and the impeller looks fine, there is some wear in the housing but not to bad. My first question is where might I find a new impeller/housing. I've tried on several sights but they don't go back to 1970. And to my next question, what else could cause it to lose suction, maybe seals? This little motor runs so good and I would like to keep it alive.

I have identified the pump kit by illustration but before I buy and install this I would like to know what else to look for.

 

[dawn schall]

Re: 70 Chrysler 9.9 cooling problems

I have recently aquired a 14' sears jon boat and a 70 chrysler 9.9. This is my first boat and knew nothing about the engine but to my surprise she fired right up after sitting who knows how long. After the third run on the water I noticed it's not pumping water at half+ throttle, I heard it start losing suction so I idled back. It pumps water fine at idle. I dropped the lower unit and the impeller looks fine, there is some wear in the housing but not to bad. My first question is where might I find a new impeller/housing. I've tried on several sights but they don't go back to 1970. And to my next question, what else could cause it to lose suction, maybe seals? This little motor runs so good and I would like to keep it alive.

I have identified the pump kit by illustration but before I buy and install this I would like to know what else to look for.

am not sure of why it wont pump at full throttle...my guess would be after so many rpms it looses suction. would tell me the pump is getting soft and starts to fold back wards leaving alot of space between the case and the impeller..it is nrubber and flexable. where did you find the impeller site. some of the impelloers original ones have been changed from the original...mine was a 20 or so fin"s. now it is a 5 fin....more improved model... due to many failing pumps. i have 12.9 hp crysler 1972...i dont know where the water is suppose to come out on it..i have a new pump. but no water coming out? im like you confused also.

 

[Nordin]

Re: 70 Chrysler 9.9 cooling problems

Water will come out at the two holes at the back on the leg. This is the idle reliefhole and it spit water at idle.
New impeller you find at franzmarine.com. He has everything you can get to Chrysler/Force OB.