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1964 Fasttwin water in gearcase

J

jbone36

New member
I inherited my grandfather's old fishing boat and his 1964 Evinrude 18hp Fasttwin a few years ago. Had the carbs rebuilt and it runs pretty decent. Problem is it is getting water in the gearcase somehow. Here's a list of everything I've replaced to help correct it...

  • driveshaft o-ring
  • watertube grommets
  • driveshaft seal
  • shift rod bushing and o-ring
  • gearcase head assembly and o-ring
  • prop shaft oil seal
  • drain / vent plug gaskets
  • spaghetti gasket
  • impeller
  • shift pivot pin / washer
  • shift linkage access cover gasket

When I installed the spaghetti gasket and gearcase cover to the lower unit, I applied a gasket sealer around the cover and over part of the gearcase assembly that the cover rides over as it looked like there was some on there before. I made sure the water tube was seated in the grommets.

When I barrel or lake test, I drain the oil and it's all milky and watery. I've re-inspected, resealed and repeated this process probably 2 or 3 x with the same results. I see no form of cracks anywhere on the housing. Today I vacuum tested it and it holds vacuum until I shift it into gear and turn the prop 1/4 turn. It drops rapidly but then stops after a second or two of the prop not turning. In neutral, I i can spin the prop all I want and it doesn't lose vacuum. The driveshaft doesn't have any obvious excessive wear to where it prohibit a good seal.

I'm handy with this stuff, but not overly knowledgable. Is there suppose to be any sort of a gasket or sealant between where the lower unit meets the mid-housing? Parts diagram doesnt show any gasket, nor did I see any old gasket or sealant when I took it apart. It seems like there should be some sort of a gasket around where the impeller housing is, but all mine had (and the parts diagram shows) is the impeller cover, the impeller, and the metal impeller plate. I feel like there is something stupid that I'm overlooking. I'll try and pressure test it in the next few days, but I'm pretty stumped at this point.

Any pointers or thoughts would be very helpful. It's a sentimental thing, so I'm willing put the time and $ into it. Thanks!!
 
How did you replace the shift rod O-ring, what was your technique? Secondly, this of course uses a bushing on prop shaft.....is it worn? What direction did you face the lip on the prop shaft seal?? Is there a groove on the prop shaft where the seal rides? Is the prop shaft bent? If the bushing is worn, Mr. Joe Reeves of this Forum, may have a new one in his stock. I have bought unavailable parts from him over the years for a very reasonable price. He has mostly retired now from the forum, but I am proud to call him one of my mentors. Appeal to me and I can get you connected with Joe. That bushing is a common wear point.
 
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timguy said:
How did you replace the shift rod O-ring, what was your technique? Secondly, this of course uses a bushing on prop shaft.....is it worn? What direction did you face the lip on the prop shaft seal?? Is there a groove on the prop shaft where the seal rides? Is the prop shaft bent? If the bushing is worn, Mr. Joe Reeves of this Forum, may have a new one in his stock. I have bought unavailable parts from him over the years for a very reasonable price. He has mostly retired now from the forum, but I am proud to call him one of my mentors. Appeal to me and I can get you connected with Joe. That bushing is a common wear point.
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Pressure tested it under water today and it held pressure until I rotated the prop with it in gear. Bubbles started coming from the driveshaft seal where it seals around the shaft. Pulled the shaft and apparently it's a lot more worn than I remember when I replaced all the above mentioned parts last summer. Used a micrometer and it's definitely quite a bit thinner. Naturally that driveshaft is a discontinued part, so I'm going to have a hell of a time finding it. If Mr. Reeves has Evinrude / Johnson part # 325800, that'd be awesome. Pretty disappointed that they don't make those anymore. What's the point in making other integral powertrain parts but not the driveshaft?
 
I do not believe they are " making " the spare parts today.-------They stocked the warehouse with parts anticipating what they might sell.-----That was old time people with old time company policy.----Totally different today.-----Making ./ storing / retrieving parts is expensive.-----It depends on where you are .---If in Canada---evinrudeparts.ca ----Might be able to help you.
 
Maybe you could get a repair sleeve pressed on to the driveshaft to compensate for the wear.
Machine shops can and do make these sort of repairs in the automotive industry, so perhaps they could tackle this as well.
I have also heard of worn shafts or what not being built up with welding, and then machined back down to the correct size.
 
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Welding will bend the shaft I think.-------Lots of good used part available as these motors were essentially the same for 20 years from 1957 to 1976 ------Your location ?
 
Check Tim's Outboard in Hackensack MN. Mike Dan or Teresa 218 682 2331. Don't think Mr. Reeves has that part but I will ask him.
 
racerone said:
Welding will bend the shaft I think.-------Lots of good used part available as these motors were essentially the same for 20 years from 1957 to 1976 ------Your location ?
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Yep, been looking up various year motors and saw that. Now I'm keeping my eye open for used motors on CL or FB in hopes someone is selling one cheap or for parts that I can use. I'm located in SW MI.
 
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