Jonsered Chainsaws

[mogulmasher]

Yeah on my old saws I always seem to land on L 1-1/4 and H at 3/4-7/8 or so. Just wanted to be sure, most of previous Jonsereds experience is with a 70e not these smaller saws.

 

[Cantdog]

Well later today I'm throwing kits in a 621 and 451ev so I'll be sure to reuse old carb gaskets.

The 621 will definitely have the same issue but don't think it's a problem on the 451 as it has a diffrent carb/intake. If I remember right the impulse corridor is a straight slot right at the top of the intake.....not a wiggly one running up the side like the others.

 

[Real1shepherd]

Best way to test the gasket is to lay it over those manifolds with the impulse channels......and make sure the gasket completely covers the impulse channels and goes right to the border of the manifold's shape all the way around.

Kevin

 

[numnutz6383]

Does anyone know the part number for a 451ev muffler gasket? Took the muffler off to remove the rust, clean the innards and ultimately paint, and methinks the gasket needs replacing,

 

[Cantdog]

For what it's worth the part number is 504 13 02 01.....but E-Gads ladd...that piston doesn't look good in the pic!!!!!! Maybe it's just oil but looks more like carbon scoring.......

 

[numnutz6383]

Yea, I thought it didn't look great. But given how little experience I have with engine work beyond the basics, I had to Google piston scoring. But, this is a 40 year old saw, cost only $50, and was meant to be a project saw after all. Here is an up close after a shop towel wipe, doesn't seem to be just oil.

 

[Maintenance supervisor]

Yea, I thought it didn't look great. But given how little experience I have with engine work beyond the basics, I had to Google piston scoring. But, this is a 40 year old saw, cost only $50, and was meant to be a project saw after all. Here is an up close after a shop towel wip, doesn't seem to be just oil.View attachment 1032253

Thats shot. Bummer

 

[Cantdog]

Yea, I thought it didn't look great. But given how little experience I have with engine work beyond the basics, I had to Google piston scoring. But, this is a 40 year old saw, cost only $50, and was meant to be a project saw after all. Here is an up close after a shop towel wipe, doesn't seem to be just oil.View attachment 1032253

Yep......that's toast for sure....sorry....

 

[numnutz6383]

Thats shot. Bummer

Shot as in "junk the saw or replace the piston ASAP" or shot as in "put it back together and run it praying for the best".

There are some pistons for the 451 available on eBay at the moment, think a small engine repair newb is capable of replacing the piston himself?

 

[Cantdog]

Shot as in "junk the saw or replace the piston ASAP" or shot as in "put it back together and run it praying for the best".

There are some pistons for the 451 available on eBay at the moment, think a small engine repair newb is capable of replacing the piston himself?

Yes that one is done...and perhaps the cyl as well but you won't know until you pull it apart......if you can find a good piston I'd grab it......a whole P&C would even be better.

 

[The Shooters Apprentice]

Shot as in "junk the saw or replace the piston ASAP" or shot as in "put it back together and run it praying for the best".

There are some pistons for the 451 available on eBay at the moment, think a small engine repair newb is capable of replacing the piston himself?

Lots of your tube videos. I believe in you.

 

[numnutz6383]

Yes that one is done...and perhaps the cyl as well but you won't know until you pull it apart......if you can find a good piston I'd grab it......a whole P&C would even be better.

Well ****. Bigger project than I anticipated.

One ships from UK (not sure if OEM, already emailed seller), and the other ships from USA, and I'm fairly certain is not OEM. Correction, the UK shipped one comes P&C.

 

[Cantdog]

Well ****. Bigger project than I anticipated.

Both available are P&C.
One ships from UK (not sure if OEM, already emailed seller), and the other ships from USA, and I'm fairly certain is not OEM. But both come P&C.

The one from the UK is actually OEM and not a bad deal.....but shipping to US is iffy they say from the add. The other is likey made in India by VEC...not bad and way cheaper...if your cyl will clean up.

 

[numnutz6383]

Lots of your tube videos. I believe in you.

Specific to this model?

 

[numnutz6383]

The one from the UK is actually OEM and not a bad deal.....but shipping to US is iffy they say from the add. The other is likey made in India by VEC...not bad and way cheaper...if your cyl will clean up.

Clean up? How does one clean a cylinder up?

 

[The Shooters Apprentice]

Specific to this model?

While I’m sure there is specific to the model, it’s pretty straight forward and the basics will be the same.

 

[Real1shepherd]

Folks clean them up with acid, hones and all kinds of tricks. However, whether it's chrome plated or Nikasil, the plating is extremely thin.

Unlike other small engine types, you don't have to worry about the cylinder being out of round. To do that, it would have to wear past the plating and of course the cylinder would be junk.

Scoring is any raised residue(which would be from the piston itself) called transfers, or any gouges you can catch your fingernail on. I use a special rubbber mandrel I make just a tad smaller than the cylinder bore and go up & down with a brown Scotchbrite pad on the outside of the mandrel/rechargeable drill on high speed. Slow process, but it doesn't remove much if any plating. Way safer than honing.

MUCH better to find a good P&C that just needs some slight cleaning as was said. Get that piston out of there and we'll help you assess the bore. Forget about that piston...she's toast.

Kevin

 

[numnutz6383]

Folks clean them up with acid, hones and all kinds of tricks. However, whether it's chrome plated or Nikasil, the plating is extremely thin.

Unlike other small engine types, you don't have to worry about the cylinder being out of round. To do that, it would have to wear past the plating and of course the cylinder would be junk.

Scoring is any raised residue(which would be from the piston itself) called transfers, or any gouges you can catch you fingernail on. I use a special rubbber mandrel I make just a tad smaller than the cylinder bore and go up & down with a brown Scotchbrite pad on the outside of the mandrel/rechargable drill on high speed. Slow process, but it doesn't remove much if any plating. Way safer than honing.

MUCH better to find a good P&C that just needs some slight cleaning as was said. Get that piston out of there and we'll help you assess the bore. Forget about that piston...she's toast.

Kevin

Thank you, this was very informative.

I'll try to find another cylinder, but I'm hoping the UK seller agrees to ship to the US.

Out of curiosity, sounds like to clean the cylinder I'd need an abrasive gritty enough to remove transfers, yet gentle so that it keeps the plating intact. My mind immediately went to magic eraser, since melamine foam acts like a very fine sandpaper, although it may not have enough abrasion to remove enough.

 

[Real1shepherd]

Thank you, this was very informative.

I'll try to find another cylinder, but I'm hoping the UK seller agrees to ship to the US.

Out of curiosity, sounds like to clean the cylinder I'd need an abrasive gritty enough to remove transfers, yet gentle so that it keeps the plating intact. My mind immediately went to magic eraser, since melamine foam acts like a very fine sandpaper, although it may not have enough abrasion to remove enough.

I think you would be forever with Magic Eraser. Folks use acid because it dissolves the aluminum transfers, yet leaves the bore plating intact. But others hate it.....so there ya go, welcome to the wonders of the Internet experts. The brown Scotchbrite pads are abrasive enough for the task, but just. I've seen vids where they used a lot more abrasion than that...makes the hair on the back of my neck stand up. And then, some swear by hones.

Kevin

 

[numnutz6383]

In an effort to avoid making this thread all about me, I've started a separate thread in regards to the restoration. I would appreciate any and all input you guys may have helping me with my first restoration.


Last thing I'll post in regards to the project on here are the images @Real1shepherd asked for of the cylinder/bore.

How is the bore? Is this cylinder salvageable?