Crank seal question. MS 250

[merc_man]

My boys ms 250 started running like crap so i checked it out and it has an air leek where the bottom clam bolts to the motor.
I just had it apart 4 or 5 years ago and replaced the seals. Just wondering if i could re use them or get new ones? Also this is first time i have had motoseal fail. Anyine else have motoseal fail?

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[angelo c]

Are the "lips" leaking (inner side by crank) or the seal at the upper corner of the bottom of that seam Where the ridge is "outter side " of seal. No info on motoseal. I've used Honda/yamabond

 

[Pincher]

Just put one together on the cheap. Pto side leaked on mine. Found a used replacement from my box of 250 stuff. I have used permatex 518 on a couple, been good for a couple of years. This last one I used permatex motoseal #29132.

 

[Creaky limb tree care]

I've found air leaks between the cases on these clamshells in the past, the last one was on an all original untouched Stihl factory build with a tiny pin size leak, so yes they do fail on the sealant! As for reusing the seals, I wouldn't recommend it, besides they are cheap enough to buy!

 

[Lightning Performance]

I used copper seal rtv on the bottom, corners and skimmed around the coated seals. Works fine with other non coated steel seals also. No leaks ever on a clamshell. Scotch brite the mating surfaces and clean them well with something stinky like solvents. Skim coat only!

 

[gduvic]

Put in new seals too much work not too. As for sealant your choice. I use different sealants depends on what I'm doing.When it comes to clam shell engines I use Stihls sealant Dirco.

 

[merc_man]

Are the "lips" leaking (inner side by crank) or the seal at the upper corner of the bottom of that seam Where the ridge is "outter side " of seal. No info on motoseal. I've used Honda/yamabond

Not the seal at all. The base of the lower clam.

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[merc_man]

Only reason i was thinking of usingmold seals is dont really want to go into many places if i dont have to with this covid 19 crap. But if better to get new ones i will. It is a lot of work as mentioned to not replace them for the money.

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[Lightning Performance]

Only reason i was thinking of usingmold seals is dont really want to go into many places if i dont have to with this covid 19 crap. But if better to get new ones i will. It is a lot of work as mentioned to not replace them for the money.

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Check them for cracks by flexing the seal under a 5x glass.
Look at the seal lips for wear. They don't distort much and can be set back in the same position.

 

[jmester]

I would probably replace the seals as you are right there. I would try and flatten the engine pan on some plate glass and sand paper. I have found that over time the corners will pull up.

 

[jmester]

I know this is not a 250 engine pan but hope this will give you a better idea of what I am talking about. Bottom pic shows the high spots

 

[merc_man]

20 dollars per seal. Think i will try the old ones first or order ebay ones.

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[Pincher]

Hl supply was out of stock last time i ordered from them. Thats why I scrounged. Besides, if they start leaking, it will go faster the second time.

 

[a. palmer jr.]

20 dollars per seal. Think i will try the old ones first or order ebay ones.

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If you order them from ebay be prepared for a long wait time. I had some ordered for about a month now and still haven't received them so I re-ordered them from another vendor and haven't received them either. I think I have other orders also from ebay which are late...

 

[a. palmer jr.]

20 dollars per seal. Think i will try the old ones first or order ebay ones.

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Where did you find them for $20? I ordered them for $1.00 per set...

 

[Finnrpm]

9638 003 1581 is the expensive one. Those will not last, it's a quick fix.
For the price of one set of 9638 003 1581 you should get 3 sets of 9636 003 1585 seals, and that's oem seals, aftermarket are even less..... in every way .......
RV

 

[merc_man]

Where did you find them for $20? I ordered them for $1.00 per set...

Local stihl dealer

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[merc_man]

Another question. When you guys reassemble a clam engine. Do ya put gasket sealer all around the seal or leave them. When i did this one i did but if i hadnt i could have got it apart with out ruining the one seal. I think i dont need to. What your thoughts?

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[Lightning Performance]

Another question. When you guys reassemble a clam engine. Do ya put gasket sealer all around the seal or leave them. When i did this one i did but if i hadnt i could have got it apart with out ruining the one seal. I think i dont need to. What your thoughts?

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How do you ruin a seal disassembling a clam shell motor?
I'm not busting your balls.

 

[merc_man]

How do you ruin a seal disassembling a clam shell motor?
I'm not busting your balls.

When i put them seals in i put motoseal around them. The one was like supor glued to the case and i had to pry it out.

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