Best carburetor to run on a ms660 walbro wj-76 or tillastion

[Lightning Performance]

Pulled the carb off my 660. It had a WJ69A 607
It has a very bad machine ridge in the tail end behind the venturi. I see how these carbs get screwed with a little sanding or grinding. Looking to put this back on a work saw. Not looking for top performance but looking for small gains. Never messed with 660 carbs, never had to. My question is, do you smooth the ridge or leave it?

 

[MG porting]

Pulled the carb off my 660. It had a WJ69A 607
It has a very bad machine ridge in the tail end behind the venturi. I see how these carbs get screwed with a little sanding or grinding. Looking to put this back on a work saw. Not looking for top performance but looking for small gains. Never messed with 660 carbs, never had to. My question is, do you smooth the ridge or leave it?

Picks please. Lol. If it's as bad as some I've dealt with get it as smooth as possible you won't see big gains but it will help a little pending on how bad it is but pitcher's would help me help you. Lol

 

[huskyboy]

I’ve seen gains thinning shafts and screws (use loctite on carb screws!!!!!)

 

[Lightning Performance]

I’ve seen gains thinning shafts and screws (use loctite on carb screws!!!!!)

I'm not messing with this carb much. Just opened it up earlier today. Clean inside. Has a 62 jet. The casting mark is minimal in the venturi but needs gone. I found four whistle clean transfer circuits. The ridge is a clean cut 1/32 step out to the boot. I'll bet they all have it. Surprisingly no burr on the edge. The next carb on the felling saw is getting ground on, so is the mill carb. This one saw is going to stay near stock. It still has the stock oem dual port muffler and baffles with screens. It has never been opened up. Going to smooth and match the intake track down to the carb box. Fresh lines and call it done.

 

[Lightning Performance]

I’ve seen gains thinning shafts and screws (use loctite on carb screws!!!!!)

You just had to say something, didn't you?....Now I have to look at all of them

 

[Lightning Performance]

WJ69A 821 and WJXX 35A K3
Are these and the WJ76 all the same size?

 

[RI Chevy]

I’ve seen gains thinning shafts and screws (use loctite on HOOSKIE carb screws!!!!!)

FIXT! I have never had a carb screw loosen up on me or any of my Stihls.

 

[huskyboy]

FIXT! I have never had a carb screw loosen up on me or any of my Stihls.

How did I know you were going to say that? Lol. Yeah actually the carb screws are peened on the ends or have some sort of loctite factory (on the throttle and choke blade screws. This is on any saw. When you remove the screw to grind the end flush to the shaft or thin the shaft and screw, loctite is *absolutely necessary* unless you want to risk loosing a topend to the screw vibrating loose and into the motor.

 

[huskyboy]

It’s not necessarily a big gain to do this carb mod on a stock saw probably... but if you are doing a bunch of mods the little gains add up.

 

[RI Chevy]

I have never had to do anything to the carb studs or screws or anything on any of my saws. ???
Maybe its just me? ‍[emoji848]

 

[huskyboy]

I have never had to do anything to the carb studs or screws or anything on any of my saws. ???
Maybe its just me? ‍

They come all set from the factory stock, it’s when you take it apart and re assemble or mod it.

 

[Chainsaw Jim]

It’s not necessarily a big gain to do this carb mod on a stock saw probably.

You'd be surprised. Thinning the rods and shortening the screws is easily equivalent to enlarging the venturi one full size.

 

[Chainsaw Jim]

WJ69A 821 and WJXX 35A K3
Are these and the WJ76 all the same size?

They should have the same bore size, but I'm not sure that the passages and jets match up.

 

[Lightning Performance]

They should have the same bore size, but I'm not sure that the passages and jets match up.

I'm sure the jettings are different. Thanks Jim.

 

[Lightning Performance]

You'd be surprised. Thinning the rods and shortening the screws is easily equivalent to enlarging the venturi one full size.

I missed this post.
Jim's right.
There is another way to gain more and doesn't have anything to do with thinning shafts or screws which does help, no doubt. Actually two more

 

[MG porting]

I have never had to do anything to the carb studs or screws or anything on any of my saws. ???
Maybe its just me? ‍[emoji848]

It's just you. Lol. Just poking fun at you.