Squealing MS362

[Matthew Arnold]

We have a MS362 which we have had from new December 2010. We recently (last month) replaced the clutch, chain brake band and needle bearing as all were nackered. All was well until today. I fired it up by the book, and it was screeching and squealing like crazy from the clutch and kept dying when small revs were applied. When it warmed up, it started fine and revved as it should. We left it an hour to cool down and it did the same again. Would it be the crank bearings on the clutch side squealing where they are seized?

[spudulike]

We have a MS362 which we have had from new December 2010. We recently (last month) replaced the clutch, chain brake band and needle bearing as all were nackered. All was well until today. I fired it up by the book, and it was screeching and squealing like crazy from the clutch and kept dying when small revs were applied. When it warmed up, it started fine and revved as it should. We left it an hour to cool down and it did the same again. Would it be the crank bearings on the clutch side squealing where they are seized?

 

Remove the clutch drum, clutch and oiler gear and see if the saw still squeals or not. Make sure you remove the clutch as running the saw with just the drum removed will take out the brake band.

 

It is most likely the needle bearing if it squeals at idle but if it does it when revving then the clutch will be meshed to the clutch so must be the crank bearings!

[Matthew Arnold]

Remove the clutch drum, clutch and oiler gear and see if the saw still squeals or not. Make sure you remove the clutch as running the saw with just the drum removed will take out the brake band.

 

It is most likely the needle bearing if it squeals at idle but if it does it when revving then the clutch will be meshed to the clutch so must be the crank bearings!

 

Did that this morning and was still squealing. Both with the clutch fully installed and without. We even tried it without the bar and chain on with the clutch fully installed.

[spudulike]

Did that this morning and was still squealing. Both with the clutch fully installed and without. We even tried it without the bar and chain on with the clutch fully installed.

 

Then if you have stripped out all the moving parts off the clutch side of the crankshaft and it is still noisy from the clutch side then it must be the crank bearings:thumbdown:

 

They will also normally sound a bit hollow and rumbly when the saw is revved up.

 

You can check the crank for play and also remove the cylinder and feel for notchiness in the crank beaings by rotatiing the crank!

[wisecobandit]

So it squealed even without the clutch, drum and oil drive removed do in effect you where down to and looking at the crank seal?

 

Was it squealing before fitting the new parts?

 

Its not a very old saw to have knackered main bearings tho theres always a possability.

If you pull it over via the starter with the engine off can you pinpoint the area better or is there no noise? (without all the clutch gubbings fitted)

[Matthew Arnold]

Then if you have stripped out all the moving parts off the clutch side of the crankshaft and it is still noisy from the clutch side then it must be the crank bearings:thumbdown:

 

They will also normally sound a bit hollow and rumbly when the saw is revved up.

 

You can check the crank for play and also remove the cylinder and feel for notchiness in the crank beaings by rotatiing the crank!

 

There was about 1/16" of play in the crank shaft on the clutch side.

 

So it squealed even without the clutch, drum and oil drive removed do in effect you where down to and looking at the crank seal?

 

Was it squealing before fitting the new parts?

 

Its not a very old saw to have knackered main bearings tho theres always a possability.

If you pull it over via the starter with the engine off can you pinpoint the area better or is there no noise? (without all the clutch gubbings fitted)

 

There was a little squeak before xmas but it had got worse. We assumed it was the clutch so replaced the shoes, springs and needle bearing but once we had dont that, the noise was more internal.

 

We stripped it down more and ran it on idle and we think we have pin pointed the issue.

 

Now had to justify to the boss getting the saw repaired as it has had problems starting from cold within 6 months of having it.

[wisecobandit]

I know its hard to explain but is it a metallic screech or more a windblown screech?

 

Only reason I ask is 2 strokes will screech/sqeal if the cylinder base gasket develops a leak and also exhaust gaskets. Its unusual for bearings to screech its normally a rumble or graunchy sound.

The other very slim chance is the crank seal itself leaking but that's highly unusual to hear it.

 

As a last resort if/when you feel you've exhausted all avenues (ie leakdown test if poss) I would whip the crank seal out to inspect the bearing better before a full strip down for the sake of a seal. Normally its pretty obvious at that point if its the bearing or not.

[GardenKit]

I had a saw in a while ago with a similar noise. I think it may have been a 440.

 

The problem on this one was the other side. A crankcase bolt had come loose behind the flywheel and had worked its way out until it was touching the rear face of the flywheel.

 

It might be worth a look.

[spudulike]

There should be zero play if the crank bearings are in good fettle - looks like one has gone:thumbdown:

[Matthew Arnold]

I know its hard to explain but is it a metallic screech or more a windblown screech?

 

Only reason I ask is 2 strokes will screech/sqeal if the cylinder base gasket develops a leak and also exhaust gaskets. Its unusual for bearings to screech its normally a rumble or graunchy sound.

The other very slim chance is the crank seal itself leaking but that's highly unusual to hear it.

 

As a last resort if/when you feel you've exhausted all avenues (ie leakdown test if poss) I would whip the crank seal out to inspect the bearing better before a full strip down for the sake of a seal. Normally its pretty obvious at that point if its the bearing or not.

 

 

Its a metallic screech. It almost sounds like someone driving along with the hand brake on a car. Its going in to the dealer next week for investigatory work. We did as much as we could but now its upto the dealer to go deeper.