I am in need of help with ms660

[adamsjosh1977]

A few months ago I bought a ms660 off of eBay. It was relatively cheap and was seller refurbished. I should have known better but I bought it..... well everything on it is aftermarket. Carb, covers, entire engine and cases. Very few things are original. I didn't know before buying. I knew the cylinder and piston were. Had a big bore kit on it. I've been using it for milling. I swapped out the "actual" stock oil pump for the bigger oil pump. Which I ordered from stihl. Which wasn't cheap. But anyway. My problem is the saw blew up. The needle bearing destroyed itself. I caught it quick enough that the crank and crank bearings are not messed up. My concern is that it turned the end of the connecting rod blue. There are no gouges or pits in it just a blue hue. Should I replace the rod. I'm replacing everything with the hyway big bore kit. But I'm using oem wrist pin, needle bearing, and c-clips. It had a new west coast setup. I know I should go back to oem. But it's crazy expensive.

 

[KYLogger]

You will probably get a better response in the chainsaw section of the forums...........there are all kinda geeky saw freaks over there.

 

[adamsjosh1977]

I'm new to this site. Which forum am I looking for. Thank you

 

[KYLogger]

Chainsaws, it's way down toward the bottom under classifieds and heavy equipment. Welcome aboard!

 

[mdavlee]

The rod really isn't replaceable. The crank comes with all of that in one piece.

 

[adamsjosh1977]

Thank you.

 

[adamsjosh1977]

I really don't want to half to split the case. I know the rule if it's in question replace it

 

[mdavlee]

You got pictures of it?

 

[adamsjosh1977]

 

[adamsjosh1977]

 

[adamsjosh1977]

 

[kr5258]

I've done several saws with a blued rod end (wrist pin) and none have come back yet. If in doubt, measure it with bore gauges to see how bad it is. If there is no scoring or excessive slop, run it.

Your pic looks like there is no appreciable damage.

Oh Gee! That second picture of the rod sure is a pretty blue! I'd look real hard at that one.

 

[adamsjosh1977]

 

[adamsjosh1977]

 

[hseII]

Definitely a Blue Crank!! Wow!

Think about it from this angle;
How many times do you want to be in the position you are in now?
If no more, I'd go ahead and do it right.

You've got options:
1) you can do it half way and hope it holds
2) you can do it with AM and hope it holds
3) you can fix it and know it's right

Aftermarket clutch covers, plastics, recoils, sure go ahead.

Pistons, Cranks, Cylinders, Rings- use the stuff the people with Reputations to uphold use; saw builders like Mastermind, TLandrum, etc...


I Don't mean to be brash, but that's the long and short of it.

 

[treeslayer2003]

looks like detonation to me, there was a thread on that a while back on the chainsaw forums......try the search function.
as far as the rod, if the new bearing fits good and is smooth i'd run it...............you really need to check out the chainsaw threads, you'll learn alot.

 

[treeslayer2003]

i'd be wantin to know what cuased the damage to start with

 

[adamsjosh1977]

It's only the rod end that's blued. The rest is semi-sythetic 2 stroke oil. I coated it all after I cleaned up the bottom end. It's a crappy picture.

 

[kr5258]

This looks like the same setup where the piston skirt was bottoming on the flywheel. Check the other threads.

The thread is on the other site SAWH AWGZ. Started by DefinitiveDave "A tale of two pistons"

 

[adamsjosh1977]

I'd also like to know what caused it to let loose. It was cooler out 30 degrees but I let it warm up for almost 10mins. I had just started doing a milling cut when it popped and let loose.