Sears 7.5 HP Crank seal?

[MahtyMaht]

Oh, Tommy Two Stroke..... I got a bad, bad feelin' your guess was right about the whole crank seal thing. It's gonna be time to go cruising soon, so I'm starting to mess with this thing. It's Model # 217-588751, serial # 48 006884. My readings about pressure testing suggested this arrangement to me



I hit the crankcase with 15 PSI with the piston all over the place, because I couldn't remember how to locate it relative to the ports. There was definitely a place in there where the air presure tried to turn the crank, but the pressure never got over 3 psi, before it fell like a stone. I could hear it blowing somewhere in there, but I couldn't tell where. Will the SK crank seal you used work on this engine? I got the ugly feeling that's where this is headed

 

[mrcrabs]

Re: Sears 7.5 HP Crank seal?

D &der....lolollol you need to pull the engine completely apart to replace the seals, your testing method proves or disproves nothing and could actually damage a good seal.

honestly you need to use the correct seals for your engine model, tecumseh used several sizes of seals on the AV817, Tommy used his method and seal because his crank seal journal was eroded.

 

[Tommy Two Stroke]

Re: Sears 7.5 HP Crank seal?

I used that particular SKF seal because the Tecumseh one is no longer available for my engine. The only thing I did differently because the crankshaft was eroded, is to use the speedi-sleeve. You would still need the same SKF seal, regardless, if your engine is of the design that requires the pressed in seal, not the seal that's held in by a circlip and backing washer.

Mrcrabs is right about your testing method not proving the seal is bad. You need to pull the powerhead off the leg, at a minimum, to check the condition of the lower seal. Using compressed air in the cylinder won't tell you anything, because there could be other causes of leakage besides a bad lower crankshaft seal, including bad piston rings, a worn bore, or a bad upper crankshaft seal.

 

[MahtyMaht]

Re: Sears 7.5 HP Crank seal?

I was actually blowing the air in thru the reed plate, but in looking some more, it would appear that I needed to snatch the head off, and plate the exhaust ports, too. Then, with the spark plug in, the crank seal's the only way out for the test air. I should probably have mentioned that the 15 psi I was putting to it, was the bled down compressor tank pressure; The big gauge on my carb block off plate has another gauge to tell me case pressure. I have since found my trusty inline regulator with gauge, so I can set it to the 6 psi I think will tell the story. My current problem is getting the engine off. I took those squirely 12 point bolts out, (two sizes), but the engine won't separate from the leg. The aluminum this thing is made of is softer than my momma's heart, so I'm scared to get too frisky with it. I have modified a couple of tips for my air chisel, padded the block with a 1x2, and rrrrrrrrrapped away in several places on the bottom of the engine. That thing is ordinarily a majic wand, but it can be dangerous. The engine started to separate, then quit moving. What am I missing? I got as short fuse, so when I got huffy, I came in here to see what you guys have to say.

 

[mrcrabs]

Re: Sears 7.5 HP Crank seal?

I came in here to see what you guys have to say.

Stop beating on that little outboard and blowing air through the reeds, it will in fact ruin them.

What am I missing?

A correct model no.!! there is no Model # 217-588751

 

[MahtyMaht]

Re: Sears 7.5 HP Crank seal?

Doope! It's 217.586751.

 

[mrcrabs]

Re: Sears 7.5 HP Crank seal?

Ok, your only wanting to separate the engine and adapter plate from the leg, there should be pry notches on both sides of the adapter plate...pry in these areas only, also on outboards that have not been apart in a long time the drive shaft will rust into the clutch or crank, if you have already removed the lower unit then this is not the problem, if not stand the little outboard on its head and shoot PB blaster through the exhaust relief holes attempting to hit the drive shaft and let it set....repeat the procedure for a day or 2 and then remove the foot (lower unit) you also must have a shift rod from what I can tell from the diagram, not sure on your model where it connects but it could also be holding you back, you have a 85 or 86 model according to you model info, be sure to use the rc-12-yc or rc-14-yc plug gaped at .30

All Sears Outboards with model numbers 217.586000 and above where built by Eska Outboard in 1985 - 1986. Eska closed and stopped production in 1986.
Most of those motors used a 50:1 Oil Mix.


just noticed my post numbers to date "666"...could I be the

 

[MahtyMaht]

Re: Sears 7.5 HP Crank seal?

Well, La-dee-da - Went out to the shop, and the engine had majically separated from the leg! Here's what I saw

The Searsparts site's parts list mentions a seal, a seal retainer, and a seal retainer ring. I got no idea how to get that seal out of there yet, because I don't see those parts, but all in all, it doesn't look too bad in there. I guess I'll start cleaning up, and take another close look, go from there. I am able to see the seal, and it's one of those with a metal OD, and a spring around the lip that rides on the crank. Seems like something a bearing house ought to be able to get. I'd still like some confirmation that it's leaking, though.

 

[MahtyMaht]

Re: Sears 7.5 HP Crank seal?

just noticed my post numbers to date "666"...could I be the

You could be Mr. deviled crab?

 

[Tommy Two Stroke]

Re: Sears 7.5 HP Crank seal?

There are other places you could have a leak. The upper crank seal could be leaking. The covers on the side of the engine, which cover the passageways from the crankcase to the cylinder inlet ports, could be leaking. The joint between the two crankcase pieces could be leaking.

The type of lower seal you have isn't as prone to failure as the pressed in single piece seal which I developed my SKF procedure for. It may be leaking, but there's a chance it may not.

 

[MahtyMaht]

Re: Sears 7.5 HP Crank seal?

Mine sure looks like a pressed in one piece seal. Looks a lot like this;
How can I find out if the seal is leaking? I REALLY don't want to take it out of there if I don't have to. I'm not seeing a bunch of corrosion on the crank or the aluminum block around the seal. Just some carbon on the end of the crank. Water passages seem quite clear. Am I right in thinking that I'd have to remove the crank to get that lower seal?

 

[MahtyMaht]

Re: Sears 7.5 HP Crank seal?

Why wouldn't I just throw this at it?

http://www.smallenginewarehouse.com..." Shaft, AV817, 2 Cycle, part number 710405B

 

[MahtyMaht]

Re: Sears 7.5 HP Crank seal?

Wonder if this would snag that seal out of there?

 

[mrcrabs]

Re: Sears 7.5 HP Crank seal?

i checked them out along time ago and called, they could not identifie the cooling chamber cast into the AV817 for Eska outboards so it could be a snow blower engine,

 

[mrcrabs]

Re: Sears 7.5 HP Crank seal?

Wonder if this would snag that seal out of there?

they generally just fall out after you take the spring and retaining clip off

 

[MahtyMaht]

Re: Sears 7.5 HP Crank seal?

Hmmmm...... The only spring I see is the one that tensions the seal lip. I don't see a retaining clip at all.

 

[mrcrabs]

Re: Sears 7.5 HP Crank seal?

your model is in that 85-86 range so your seal is as you described, one way to pull that seal is to drill 2 small holes on either side and use some long screws as pullers, if you have room....theres actually a tool called a seal puller

 

[MahtyMaht]

Re: Sears 7.5 HP Crank seal?

Where can I see a list of what's in Tecumseh gasket set # 510297A?

 

[MahtyMaht]

Re: Sears 7.5 HP Crank seal?

I'm a little worried about punching holes in that seal to extract it - The closed face of the seal is against the bearing, so the minute I get a hole thru the seal, I'm into the bearing. I ask about the gasket set, because I see where two stroke oil has been creeping out at the port covers and head gasket, and I'd like to see about stopping all that.

 

[mrcrabs]

Re: Sears 7.5 HP Crank seal?

Well now your you might as well replace that old bearing while your at it, the stator plates top crank bearing needs replaced as well as the seal, I see from your pics that you have a deluxe model direct drive to the foot, do you have a set of calipers so you could give me the ID of the hole the seal sets in?,