Project 660

[psuiewalsh]

A friend asked me to take a look at a 660 he had picked up a while ago. He said it needed a few things and asked if I would go through it. I'm going to need some advice on this one as I have it torn down now.

 

[psuiewalsh]

Top cover was missing the two vertical screws. Looks like the threads are stripped out. I located a reasonably priced M5 timsert kit on ebay. I am going to try them in this thin casting.

 

[angelo c]

Easiest saw you'll ever rebuild. You'll never touch one a dem stinky hooskies after building such a well deserved piece of machinery as an MS 660...

Are we talking about an MS 660 ?

 

[psuiewalsh]

The clutch was in a bad way. I am going to try 3 new oem springs. I have had the AM springs fracture on me on other projects. Going to get a new drum kit and bearing as the set on here was wobbly on the crank

 

[angelo c]

Jeepers give that thing it's decade old first bath.... !!!!

I would try to tap with an M( or the next size up) and use that. It's not a critical stress point(holding plastic cover down)

 

[psuiewalsh]

Yes. I have been through 10-12 before. The supprises and questions are coming up. MS660/066

 

[psuiewalsh]

M6 is a stretch on thin wall. I think the inserts will be better long term fix

 

[psuiewalsh]

Recoil was held on with one screw out of 4. Pawls fell out when I lifted it off

 

[psuiewalsh]

Looks like a problem here. Saw was vac tested and pressure tested. There was a very small leak between the cylinder and case. Seals test good.

 

[Moparmyway]

Jeepers give that thing it's decade old first bath.... !!!!

I would try to tap with an M( or the next size up) and use that. It's not a critical stress point(holding plastic cover down)

M6 is a stretch on thin wall. I think the inserts will be better long term fix

My vote goes to the inserts as well.
If you go to a larger bolt, you have to ream the cover inserts

Running the inserts keeps all screw hardware the same too, if its ever going to get torn down, it'd be easier going back together.

 

[psuiewalsh]

 

[psuiewalsh]

Looks like someone sanded the top of the piston.

 

[Moparmyway]

Crankcase looks clean !!

 

[psuiewalsh]

they been here too. Think I should sand a little to even things up?

 

[psuiewalsh]

This is not so good looking. Maybe this is what broke the piston.

 

[psuiewalsh]

 

[psuiewalsh]

Plating is chipping a little can the edge be relieved to smooth it on the bottom of the intake?

 

[psuiewalsh]

Piston is in backwards the pins are toward the exhaust. Is there any reason for this on this hacked cylinder? It looks like the intake was not widened. The plating is on all edges of the intake.

 

[Red97]

Just reread you post, must have just been an oops.

Cut the base and set the squish, reshape the exhaust and fill the intake. Good to go

 

[psuiewalsh]

I think that will work.

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