MS650 Magnum - AKA install a 660 top end

[Bobby Kirbos]

For a couple of reasons, I decided to F-- the idea of Chinese clone. I have an MS650 on its way to me from @David Major (thanks dude) that has low compression, so I'm thinking that a new top end may be in order. In the end I will have what I wanted - a quality 6-cube(ish) saw that isn't made of Chinesium, at a cost that doesn't drain the bank account.

Here is where I am at the moment:

• I don't make a living cutting wood, so squeezing out every last drop of performance isn't necessary. BUT I also don't want something that runs like a turd.
• I want a saw for the 30"+ logs that I occasionally run in to. This would take some of the load off of my rebuilt Poulan 245, which does well with the 28" bar but would be running balls out with anything longer. It does way better with the 24" setup I currently have on it.

After researching the various 660 top end options, where I ended up:

• An OEM top end is best, but the price blows up the idea of not spending a ton.
• Big bore kits are hit-or-miss for quality and usually don't add any noticeable performance gains vs. a good quality AM top end.
• The AM circlips suck, use OEM.

So I plan to use:

• Meteor cylinder, standard 54mm bore
• OEM circlips

As for the piston, I'm debating between 2

• Hyway pop-up
• Meteor

So the question to those who know this machine way better than I do - Is there enough performance gained by using the pop-up piston to make it worth the extra few $$, or should I just use the whole Meteor top end kit (excluding clips) and go make firewood?

 

[pioneerguy600]

Good for you, leave the cheap AM stuff for the amateurs...

 

[Bob Hedgecutter]

Here is where I am at the moment:

• I don't make a living cutting wood, so squeezing out every last drop of performance isn't necessary.
• I want a saw for the 30"+ logs that I occasionally run in to.

So I plan to use:

• Meteor cylinder, standard 54mm bore
• OEM circlips

As for the piston, I'm debating between 2

• Hyway pop-up
• Meteor

So the question to those who know this machine way better than I do - Is there enough performance gained by using the pop-up piston to make it worth the extra few $$, or should I just use the whole Meteor top end kit (excluding clips) and go make firewood?

I do not know the machine much better than you do- but you kind of answer your own question- with "every last drop" and "occasionally run into".
If it were my personal saw- I would be more than happy with the Meteor top end standard piston- the 650/660 is no slug and will do what you are asking of it.
Personally I have never had a problem using the Meteor supplied circlips (touch wood!)

Later down the track, after you have cut a few cords or wood with the Meteor set up, order a Hyway pop up when you can afford it, during some down time, swap the pistons and see what you think- willing to bet you don't find huge gains.

My vote goes for, use the Meteor kit and go cut wood.

That is of course if the saw indeed needs an entire top end when you get it, might just need piston and rings- or just rings....... standard 650's still cut wood good.

 

[L34]

Contact outbushman in Aust.
I can get a top end for about 1/2 the price I can get from dealer.
He ships to usa too.
Just Google outbushman.
Tell him Chris in Tassie said to contact you.

 

[L34]

Some on the 'other' site won't use Meteor cylinders now as they recon the port timing is to far out.

 

[Bobby Kirbos]

Contact outbushman in Aust.
I can get a top end for about 1/2 the price I can get from dealer.
He ships to usa too.
Just Google outbushman.
Tell him Chris in Tassie said to contact you.

Thanks for the tip.

 

[L34]

That's Aust$ not US$ so the price difference might not be that great to you.

 

[pioneerguy600]

Some on the 'other' site won't use Meteor cylinders now as they recon the port timing is to far out.

Meteor pistons have proven to be good but you are correct, some Meteor cylinders are not the greatest. I stick to OEM, even good used OEM is better than AM in my opinion, only worth what you pay for it by the way. I recommend using OEM whenever possible but have found the pistons suitable. I doubt you would have much of a problem finding good used OEM cylinders on here if you asked.

 

[L34]

Agree piston good,Cylinder not so in timing.