Sears 7.5 HP Crank seal?

[MahtyMaht]

Re: Sears 7.5 HP Crank seal?

I'm goin' in - Here's what I saw.
4


The dark zone on the crank kind of makes me wonder if there's not some wear there, but I'll mic it up later. The gasket under the stator casting calipers at .030" thick. I found a number on the block casting - It's 881998 This may help identify the Small Engine Warehouse short block ***'y they're selling for $65 or so, as a useable outboard block for 7 1/2 HP. If that'd work, it'd prolly be cheap as getting the upper and lower bearings and seals, with all the required gasketry. We'll see. Otherwise, onward, thru the fog!

Oh, yeah - Do the lines on that piston suggest replacement?

 

[mrcrabs]

Re: Sears 7.5 HP Crank seal?

Small Engine Warehouse short block

There's no way possible in a million years that short block will have your crankshaft, however piston, rod, bearings and block may be??? Edit: I was sure wrong about this:facepalm:

Oh, yeah - Do the lines on that piston suggest replacement?

There's no way possible in a million years you will ever find a new NLA piston, well maybe I found one by chance and got it for $3 on ebay.
My technique for cleaning up a scored piston is first use fine grit sand paper rolling the piston in it. then use a small brass brush to roll over the scores and scuffs....works for me

 

[MahtyMaht]

Re: Sears 7.5 HP Crank seal?

Holy Crapinoli! I skifed a 640-20 from the dump a couple of years ago, because it was close enough to mine, that I thought it would have some useful parts, I always thought it was probably a 5 hp, and it was lying dead in the dump, because some poor blackguard couldn't get a spark out of that crapweasel electronic doodoo tecumseh used to do in the early eighties. It had a good carb, reeds, flywheel, port covers, and who knows what else, so I snagged it. It's complete lower unit was there, too, so I scarfed that, too. I now realize it's a 6 cubic inch engine - that's 7.5 Hp, same as mine. Oh, reeeeeally. My carb fits, the drive shaft fits the crank splines, and my points/throttle plate fits the stator casting. The only thing left would be whether or not the leg would bolt up. That would appear to be a yeppers. I cannot bufrigginlieve that powerhead may bail me out of this whole mess. It's obviously low mileage, because the electronic ignition bit the wall early in it's life. Compression is stiff. Take a look at some comparative pics - see any differences?

 

[mrcrabs]

Re: Sears 7.5 HP Crank seal?

I learned something, I did not realize that the 85-86 non deluxe models used a neutral shift dog in the foot and retained the neutral spark advance lock with no reverse but the water pump turns all the time when running.
Eska had done away with the old clutch design sometime in the 80s

your a lucky dog having that spare engine.

 

[MahtyMaht]

Re: Sears 7.5 HP Crank seal?

Lucky, and I hit the dump twice a day, three times a week. It's beginning to look like the spare is going to be a dicier adaptation to the leg than it looked like at first. The plates between engine and leg are different, and I'm deliberating whether to attempt the hack. The plate with the carbon black is the spare's, and it only has two water passage holes, where the old has three. The old motor's plate has an extension on the left that interferes with the fins on the spare, otherwise it would bolt up. There are two water passages left of center that are in part of the old plate's gasket sealed area, and they are below the gasket surface on the spare.

 

[mrcrabs]

Re: Sears 7.5 HP Crank seal?

surely you can change all plates to your originals?

 

[MahtyMaht]

Re: Sears 7.5 HP Crank seal?

The plates are not interchangeable. The driveshaft, watertube, and bolt holes seem to match, but the outside dimensions and water passages are different. I've got to get out there and stare at the durn thangs, now, and see if I can figure out exactly how the water moves thru'em. Then I can decide whether or not to attempt a hack.

 

[Tommy Two Stroke]

Re: Sears 7.5 HP Crank seal?

I learned something, I did not realize that the 85-86 non deluxe models used a neutral shift dog in the foot and retained the neutral spark advance lock with no reverse but the water pump turns all the time when running.
Eska had done away with the old clutch design sometime in the 80s

your a lucky dog having that spare engine.

Eska was making engines without the old clutch design even before the 80's. My 217.585930 7.5hp Gamefisher has a clutch dog in the lower unit, not right under the engine like so many Eskas had. There's a rod that goes all the way down to the very bottom and connects the shift lever bellcrank to this clutch dog. Last time I checked, my engine was, I think, a 1973 or 1974.

 

[mrcrabs]

Re: Sears 7.5 HP Crank seal?

yep Tommy I know that, I have a 1973 deluxe with F-N-R but I didn't know that later years Eska F-N models had got away from the clutch....is your model F-N or do you have reverse too?

 

[mrcrabs]

Re: Sears 7.5 HP Crank seal?

The plates are not interchangeable. The driveshaft, watertube, and bolt holes seem to match, but the outside dimensions and water passages are different. I've got to get out there and stare at the durn thangs, now, and see if I can figure out exactly how the water moves thru'em. Then I can decide whether or not to attempt a hack.

the actual bottom of the engine should be exactly the same on both engines, forget the plates look at the actual engine

 

[Tommy Two Stroke]

Re: Sears 7.5 HP Crank seal?

yep Tommy I know that, I have a 1973 deluxe with F-N-R but I didn't know that later years Eska F-N models had got away from the clutch....is your model F-N or do you have reverse too?

Mine's only F-N, no Reverse.

 

[MahtyMaht]

Re: Sears 7.5 HP Crank seal?

The bottom of the engines ae the same except that the gasket surface on mine extends further toward the topend that the spare's; The gasket surface goes thru 4 cooling fins on mine, only 3 on the spare. Because everything else about the engine is the same, I'm thinkin' maybe I'll extend the gasket surface on the spare one more fin, and see what I think about it. Mine is an F-N, so is the lower unit I got, (complete with prop). I have to use my plate to fit the water passages on the leg.

 

[MahtyMaht]

Re: Sears 7.5 HP Crank seal?

HA! I cut a 4th fin off the spare's cylinder, and my plate dropped right on. It's really starting to look like this pig's gonna fly. I have managed to extract that stinkin' needle and seal out of the stator casting, but I never saw a ring. I had to destroy the seal to get it out, and now I worry that the mystery ring was part of the trash. If I knew it's dimensions, I could make one, but I don't have a clear idea of what the thing is doing in there. I guess it doesn't matter for the purposes of this season, since it's now the spare, but I wouldn't mind it being running.

 

[MahtyMaht]

Re: Sears 7.5 HP Crank seal?

Will this impeller work for my engine?

http://www.boatsportandtackle.com/servlet/Categories

 

[mrcrabs]

Re: Sears 7.5 HP Crank seal?

just send a e-mail to them with your model no. be sure to get a new shear pin with you impeller....I also like to replace the drive shaft seal at the pump...more water pressure

 

[Tommy Two Stroke]

Re: Sears 7.5 HP Crank seal?

just send a e-mail to them with your model no. be sure to get a new shear pin with you impeller....I also like to replace the drive shaft seal at the pump...more water pressure

Even more important is the gearbox seal just under the water pump. If that seal leaks, it means water in the oil....and that seal is usually badly neglected because most people don't do anything to it when they change the water pump impeller.

 

[mrcrabs]

Re: Sears 7.5 HP Crank seal?

I guess I should have said both shaft seals Tell me Tommy does your lower have the O ring, plastic retainer and seal below the water pump? and by the way my 77 Eska has the upper clutch, do you have any solid info on when Eska went to the clutch dog in the lower unit...I did notice a change in the foot design from ebay pics that seem to be 79 or 80s models with the design change which included a diffrent prop and nut as well, they seem to be a tad bit longer in the gear housing but still a 2 piece, the deluxe 7.5 used the same foot as the 9.9-15hp.

 

[Tommy Two Stroke]

Re: Sears 7.5 HP Crank seal?

I guess I should have said both shaft seals Tell me Tommy does your lower have the O ring, plastic retainer and seal below the water pump? and by the way my 77 Eska has the upper clutch, do you have any solid info on when Eska went to the clutch dog in the lower unit...I did notice a change in the foot design from ebay pics that seem to be 79 or 80s models with the design change which included a diffrent prop and nut as well, they seem to be a tad bit longer in the gear housing but still a 2 piece, the deluxe 7.5 used the same foot as the 9.9-15hp.

The lower unit on my 217.585930 has a one piece pressed in seal under the water pump - there's no o-ring, retainer, and seal. I don't have solid info on when Eska went to the clutch dog in the lower unit. I need to check Brix's website to verify the date on my engine - I think it's a 73 or 74 but I will check. Interesting that the deluxe 7.5 used the same foot as the 9.9-15 - in fact, I looked at a pic of a 15 lower unit on Ebay and it looks exactly the same as the one on mine. Now if I could just find a 9.9 or 15, that would be lovely. I have a big enough collection (Elto 1.8, Eska 3.0, and Eska 7.5), but one more larger unit would be nice!

 

[mrcrabs]

Re: Sears 7.5 HP Crank seal?

7.5 deluxe and the 9.9/15hp use a single piece gear case...its stouter and heaver than the typical Eska lower unit and has a full set of gears,
hopefully these to pics will show the dif,

the Eska ad shows the style of gear box I think you guys have, notice the inspection plate.

Edit: Ok so they changed it in 1978, brixnet shows the 1977 with clutch assembly 56026 and the 1978 model shows clutch assembly F-N DIx

 

[Tommy Two Stroke]

Re: Sears 7.5 HP Crank seal?

7.5 deluxe and the 9.9/15hp use a single piece gear case...its stouter and heaver than the typical Eska lower unit and has a full set of gears,
hopefully these to pics will show the dif,

the Eska ad shows the style of gear box I think you guys have, notice the inspection plate.

Edit: Ok so they changed it in 1978, brixnet shows the 1977 with clutch assembly 56026 and the 1978 model shows clutch assembly F-N DIx

That plate allows access to the shift linkage disconnect, similar to the way it's done on OMC engines. The lower unit looks the same as mine, in the pics.