Practical advice checking crank seals.

[boltonranger]

This is an Echo engine;
A trimmer actually; it's squirrelly when it warms, I've gone through the carb; and fuel lines; So I thought I'd check the seals...

I took off the rear cover (recoil housing) and the nut that holds it on the crank.
So I can see the seal now. But since the recoil housing is off, I can't really crank the engine over.
Should I put the soapy water (or some say wd-40) on the seal and re-assemble to crank then pull it all off and look?

Since it's a negative pressure what would I see anyway?
-br

 

[ericjeeper]

Vacuum test

This is why you must perform a vacuum test. Remove the muffler and the carb block off both ports. On one of the plates used to block off the port you must attach a tube to hook up a vacuum pump..

 

[Lakeside53]

You need to seal off the carb and exhaust, then connect another point (like though the plug hole or via the sealed carb/exhaust). Pressure for the obvious leaks (8psi max), and .5bar vac for seals. Use a light oil on the seals to identify which is failing (it will suck in).

 

[Lakeside53]

Ha! Beaten by Eric!

 

[RiverRat2]

Ha! Beaten by Eric!

Ha!

 

[teacherman]

You need to seal off the carb and exhaust, then connect another point (like though the plug hole or via the sealed carb/exhaust). Pressure for the obvious leaks (8psi max), and .5bar vac for seals. Use a light oil on the seals to identify which is failing (it will suck in).

What is 0.5 bar of vac in column inches?

(or in cubits of zirconium....)

 

[ray benson]

.5 bar = 7.25 psi

 

[klickitatsacket]

fire it up and let it idle and spray a little starting fluid around the seals. IF you have a leak the engine will die.

 

[ericjeeper]

Sorry Lakeside

But it was raining here.. I was pretty quick on the keys to beat the master..

 

[Lakeside53]

I was hung over.:greenchainsaw:

 

[madrone]

This is an Echo engine;
A trimmer actually; it's squirrelly when it warms, I've gone through the carb; and fuel lines; So I thought I'd check the seals...

I took off the rear cover (recoil housing) and the nut that holds it on the crank.
So I can see the seal now. But since the recoil housing is off, I can't really crank the engine over.
Should I put the soapy water (or some say wd-40) on the seal and re-assemble to crank then pull it all off and look?

Since it's a negative pressure what would I see anyway?
-br

AAAhhhheeemmmm, about the question.
As the super fast experienced guys mentioned the vacuum test is your best option. Testers are cheap ($20).
If you're antsy, and can get the engine running and then get a look at the seal in question, spray some wd40 on it and you will see it suck up.
Course Klick... mentioned the starting fluid trick which should work also.
Vacuum tester has a million and one other things it can do like bleed brakes, test car vacuum system, draw blood......

Ok, where were we......

 

[Lakeside53]

Good luck getting anywhere near the clutch side seal when the engine is running.... unless you take off the clutch and oil pump...

Lot easier just to vac test it.

 

[madrone]

Good luck getting anywhere near the clutch side seal when the engine is running.... unless you take off the clutch and oil pump...

Lot easier just to vac test it.

B4 I got my tester this worked on my 210. I didn't know if it would work on the echo trimmer though.
Just putting out options.
:greenchainsaw:

 

[klickitatsacket]

Good luck getting anywhere near the clutch side seal when the engine is running.... unless you take off the clutch and oil pump...

Lot easier just to vac test it.

all you have to pull is the clutch covers. If there is a vacume leak it will find it's way in there. I use this method because I find it way faster than trying to block behind the carb and muffler.

 

[Lakeside53]

lolol For some reason I thought we were talking about a 290.. :monkey: never mind...


But... on a trimmer it is still a PITA on the clutch side anyhow.

 

[Lakeside53]

all you have to pull is the clutch covers. If there is a vacume leak it will find it's way in there. I use this method because I find it way faster than trying to block behind the carb and muffler.

Not with an oil pump on the way! I've never had any luck at all. Maybe your pumps leak more than mine :greenchainsaw:


On the muffler I just loosen the screws and slip a rubber sheet down behind. Carb.. I use a block because I have one.

 

[RiverRat2]

lolol For some reason I thought we were talking about a 290.. :monkey: never mind...


But... on a trimmer it is still a PITA on the clutch side anyhow.

I was hung over.:greenchainsaw:

LOLOL!!!!!! not from too much singlemalt!!!!!