1973 70hp Chrysler OB

[mrwiggles2]

Hi, I have this outboard that I purchased a seal kit for due to a large volume of water in the lower unit. However, I'd like to replace the water pump and gaskets too. What kit do I need to purchase? My water pump is a 3085 replacement, but can't locate the kit, just pump.

The other thing, I was wondering if I can use a different pump with less vanes. I heard the ones with less vanes pump more water. The 3085 (Sierra) pump seems to have a lot of rubber vanes.

Thanks! I believe the outboard is model 707HF.

 

[Mike2076]

Re: 1973 70hp Chrysler OB

Hello,go online to mastertech outboards and call him.he has help me with getting parts for several of the old force and chryslers i have fooled with.Good luck.Mike

 

[mrwiggles2]

Re: 1973 70hp Chrysler OB

Thank you. I went on his site and ordered the water pump kit for my motor. It does look like the kit has been upgraded to use the impeller with fewer vanes. A lot of good info on that site too.

 

[Mike2076]

Re: 1973 70hp Chrysler OB

Hello Craig, im glad they had the stuff you need,they are a helpful bunch over there.happy boating Mike

 

[mrwiggles2]

Re: 1973 70hp Chrysler OB

Just an update on my progress. I completely tore my 707HF apart and I'm pretty proud of the work I've accomplished and thanks to Frank and Mike I'm looking to be in good shape.
The only issue so far was the drive shaft seal. After pulling the 2 piece LU apart, I didn't know I could use a soft mallet on the end of the driveshaft. I was using a long screwdriver and trying to pound out the seal that way. Well, I crushed the bearing, so my local shop is pressing on a new one. Probably a good idea to have that bearing replaced anyway instead of using it (probably could have been used, but didn't want to chance it).
The only remaining seals in the kit are the driveshaft seal, two nylon looking seals I think are for the vent and drain plugs, an orange hockey puck seal that I believe to be the shift seal and Lastly a tiny o-ring, smallest o-ring in the kit. I have no idea where that goes. Maybe the pivot shift screw that no one is supposed to touch?

Here are some pictures.


Notice the crushed o-ring, and the flattened large o-ring. This is where the oil was dripping from my LU, so there is the leak.

 

[mrwiggles2]

Re: 1973 70hp Chrysler OB

Anyone know what the tiny o-ring is in the seal kit I'm installing? Think it goes on the shift pivot screw? Currently there is a nylon crush ring for that screw. Can't figure that one out.

 

[81 beachcomber]

Re: 1973 70hp Chrysler OB

Anyone know what the tiny o-ring is in the seal kit I'm installing? Think it goes on the shift pivot screw? Currently there is a nylon crush ring for that screw. Can't figure that one out.

is it the same size as the o-ring?? im doing the exact same thing to my 1979 79hp and my kit came with two tiny o-rings. dont know where they go.

one question? how did you pull the driveshaft out to get the seal under the water pump. i pulled off the water pump and have my lower unit in two pieces, do i just pound out the driveshaft with a mallet as you mentioned earlier or is it held in by something else??

also the first stud (to the front of the leg, away from the prop) is there supposed to be an o-ring at the top of it on the top section of the lower unit. one fell out from the top when i was trying to get the d-shaft out and i think it came from there, however i dont have one to match in my seal kit.

thanks and good luck with yours also

 

[john from md]

Re: 1973 70hp Chrysler OB

One little o ring goes over the shift rod and sits at the bottom near the gear case.

Regards,

John

 

[mrwiggles2]

Re: 1973 70hp Chrysler OB

Thanks, I figured it out. I went to a local marine dealer, small shop and they were very helpful. I needed a new bearing put on the drive shaft as I beat it up good getting the seal out. Picked it up yesterday. Started working on the boat around 6pm, finished at 1am. I'm beat. If I could have made it more difficult, I did.

Sealed the LU up and found I forgot to attach the bolt back on the pinon. Rip it apart. Put it back together, figure out how the shift seal works and that I never took out the old one. Rip it apart. Put it back together and find the water pump intake screen laying off to the side of the workbench. Rip it apart. Ever see a grown man cry?

At any rate, caught a second wind around 11pm and got the LU on the boat around 1am. Today I put the oil in and start it up with muffs. See if I did it right... Not a hard job, if you aren't tired.

 

[81 beachcomber]

Re: 1973 70hp Chrysler OB

i just finished mine. was pretty straight forward except i had a b**** of a time getting the driveshaft seal out. i tried pounding out the drive shaft with a rubber mallet as metioned earlier. lol no luck on that i couldnt even move it a bit. out came the big toys. lol i used a sledge hammer and a board of wood. a buddy i work with held the board as i pounded out the shaft. was pretty good haha. once that was done everything else went smooth. come time to put that shaft seal in again i had to find a socket big enough for it and also had to be a 1" drive so i could slide it over the d-shaft. i had to machine the $5 socket on the metal lathe so it was the correct diameter and then pounded in the seal.

Cant wait for the weekend so i can take her out

hopefully she dosent leak