Diagnosing broken crank seal ring

TBarCYa

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Apr 13, 2005
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Does anyone know of a way to test for a broken crankshaft seal ring?? The problem I'm haveing is with the #1 cylinder only (#2 is fine) so I'm thinking that the seal ring should be good, but I want to rule it out as a possible cause of my problems.<br /><br />Thanks.
 

Dhadley

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Re: Diagnosing broken crank seal ring

What problem are you having?
 

TBarCYa

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Re: Diagnosing broken crank seal ring

The problem is that the #1 cylinder on my 85 90hp is spitting gas out from the carb throat. The reeds look good but I'm planning to swap the reed block out anyway to make sure it's not the issue. If not the reed block, I would think a broken crankshaft ring may be the cause but I'm really not sure.<br /><br />I'm not determined that the crankshaft ring is broken but I want to be able to rule it out after the reed block is replaced.
 

Dhadley

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Re: Diagnosing broken crank seal ring

The crank seal ring shouldnt do that. Even if it is broke its still behind the reeds. And even if its broke its still, most likely, in the groove on the crank.<br /><br />When you say the reed block looks good, does that mean you have the intake off and the block out?
 

TBarCYa

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Re: Diagnosing broken crank seal ring

I had the block out to change the gasket since I couldn't see anything physically wrong with the reeds. When I reinstalled everything, it ran fine for about half an hour before running like garbage again.<br /><br />I have a spare reed block that I have ready to go in when I get back to the boat tomorrow.
 

Dhadley

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Re: Diagnosing broken crank seal ring

When you pulled it out was the gasket bad or out of place?
 

TBarCYa

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Re: Diagnosing broken crank seal ring

No, the gasket looked good. Dirty, but otherwise good. I replaced it anyway just to be safe.
 

Dhadley

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Re: Diagnosing broken crank seal ring

What do you mean by dirty?<br /><br />If you replaced it and it ran good for a while maybe theres something going on there.
 

Dhadley

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Re: Diagnosing broken crank seal ring

Did you replace the gasket correctly? The short side out?
 

TBarCYa

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Re: Diagnosing broken crank seal ring

By dirty, I mean that there appears to have been some varnish around the gasket. I matched the gasket to the reed block before installing it so I'm pretty sure it's in right. I'll change the gasket again when I replace the reed block tomorrow.
 

TBarCYa

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Re: Diagnosing broken crank seal ring

DHadley,<br /><br />You were right on the money... Apparently, the gasket must not have been in correctly and broke apart causing the foul running. I replaced the gasket (again) and it was running much better. Of course, after a short time it started acting up again so I also replaced the water pump and thermostats and ran it on the earmuffs for about 15 minutes with no difficulties whatsoever and it was not spitting from the carb. The heads stayed cool, the water from the pee hole was cold and the water coming from the prop was warm. <br /><br />Thank you for all of your help.
 

Dhadley

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Re: Diagnosing broken crank seal ring

Great to hear!<br /><br />I cant tell you how many times that happens with the reed box gasket. The difference is so small its kind hard to notice if you arent looking for it. <br /><br />Wanna know how I know about that? And no, nobody told me.
 

rodbolt

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Sep 1, 2003
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20,066
Re: Diagnosing broken crank seal ring

hahahaah seems Dhadly found the gasket thing like I did. the other reed gasket thing I see a lot is no one removes the plastic from the gasket side with the adhesive. not all gaskets have the plastic cover but if it does and its not removed it will cause a problem later :) .
 

TBarCYa

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781
Re: Diagnosing broken crank seal ring

I noticed that only one of the 4 I bought had the plastic... Had me a little worried at first.<br /><br />Unfortunately, my saga continued after the reed gasket. Just today I was out on the water and continuing to have problems. I pull over and drop anchor then pull the spark plugs. One plug comes out completely covered in carbon deposits. I put a used but clean plug in and she runs fine. Tie up at the dock and head to the store for some decarb spray and four fresh plugs. After doing the decarb and changing the plugs (again) she ran great all day long. That's the first time I've gotten a full day (to the island and back) without her acting up. <br /><br />Thank you to everyone who helped me out. Every comment and suggestion is greatly appreciated.
 
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