White limiter cap mayhem MS391

[Bally1020]

The springs were never there. Only the white caps. Without springs, only the white caps as you said will hold the screws in place. But ideally, crud or no crud i do not want the white caps in there, just like every other saw or weedwacker i have, there are no caps and no special tools and no limit on adjustment. So as far as functionality goes, do you think these springs i put in will hold the screws in place without air leaking etc? Im not an engineer, i just want the saw to cut. I just cant tell if the tiny circular ring on the needle is where it seals or not.

I'd rather hAve springs and put something else to cover the holes for crud protection than have to buy new caps and find a special tool somehow. Nobody sells them online. Its a big joke.

 

[HarleyT]

Set the carb where you want it, then put some melted wax or kid's paste in there to lock and seal things.

 

[ChuckMI]

It looks like this saga is about over, but here are left-handed screws if anybody is interested https://www.mcmaster.com/left-hand-threaded-screws/

 

[Mad Professor]

It looks like this saga is about over, but here are left-handed screws if anybody is interested https://www.mcmaster.com/left-hand-threaded-screws/

So anybody have the tool and a caliper? McMaster lists 3- and 4-mm lefty screws

 

[1hp]

had to order the tool from Australia. be here in a day or 2. the Echo tool is 2.5mm. also they make an oversize one at 3mm.

 

[SteveSr]

The springs were never there. Only the white caps. Without springs, only the white caps as you said will hold the screws in place. But ideally, crud or no crud i do not want the white caps in there, just like every other saw or weedwacker i have, there are no caps and no special tools and no limit on adjustment. So as far as functionality goes, do you think these springs i put in will hold the screws in place without air leaking etc? Im not an engineer, i just want the saw to cut. I just cant tell if the tiny circular ring on the needle is where it seals or not.

I'd rather hAve springs and put something else to cover the holes for crud protection than have to buy new caps and find a special tool somehow. Nobody sells them online. Its a big joke.

The crud I was referring to gets into the carb through the empty needle hole.

For springs I would look to an old carb. However the fully compressed length MUST be less than the distance between the carb face and the rear face of the needle screw head. i.e. the new needle may be shorter than the ones that used springs.

Another option may be to gut a set of new caps so they don't limit needle rotation and just install them to hold needles in place.

 

[Bally1020]

First time revisiting in a great while. I think i had installed my cut in half spring before reading the last post. Luckily i think the saw ran just fine without the screws moving. But it is a good point about the length i will remember for any future fixes so thank you for the tip. I didnt want to put any glue or wax in there, imagine you got your saw back from a dealer with a carb full of wax and then adjusted it. The wax would move and might not let the screws be set any more. So i copied all the other carbs i have seen. Tested saw two different times , cold morning, hot afternoon. Started and ran nicely. Friend was happy. Thanks yall!