MS 460 L needle valve head broke off!

[ChipChomper]

I just got a used MS460 and while adjusting the carb (Walbro HD-16), the head of the Low needle valve adjusting screw broke off.



I am looking at extracting it with a left handed drill but this will be very difficult because the screw is only about 1/16". It looks like getting a drill (1/32") this small in left hand twist will be difficult relatively expensive once shipped. Any one have ideas or experience that might help me get it out? I'm tempted to just get a cheapo probably Chinese carb, but really not sure if it will deliver-- it appears parts for the HD-16 carb aren't all that easy to find as it appears to be discontinued.

All help welcome except telling me I'm a dumbas$$for breaking off the head of the L screw cuz I am embarrassingly aware of that at this point.

 

[rupedoggy]

If it was mine and I wanted to save it, I would take my cutoff wheel on my dremel and grind a new slot into the broken screw and try to remove. Yes it will probably mess with the sides a bit but that is a non-critical area for carb function. Mike

 

[pioneerguy600]

Is the screw seized or was it rammed in too hard damaging the port.

 

[ChipChomper]

If it was mine and I wanted to save it, I would take my cutoff wheel on my dremel and grind a new slot into the broken screw and try to remove. Yes it will probably mess with the sides a bit but that is a non-critical area for carb function. Mike

I may try that-- thanks!

 

[303_enfield]

A good welder could tac it. Or a cheap HF left hand threaded bit could back it out.

Good luck!

 

[ChipChomper]

Is the screw seized or was it rammed in too hard damaging the port.

Screw didn't seem to be adjusting or seating/completely closing, then the head fell off so I'm not entirely sure what the situation is. Thanks for mentioning that it might be seized, I didn't think of that. In that case I might be effed on the carb as a whole but I
l'll still try to to get it out cuz oem replacements for the HD-16 seem to be running $150+. The H screw comes out just fine.

I've heard the carb for the 461 works on the 460 after replacing some of the choke linkages. Are there any quality carbs being made at present that will fit a 460? There seems to be no middle ground between $12-20 AM knockoffs and $150+ oem carbs that are out of production.

 

[ChipChomper]

A good welder could tac it. Or a cheap HF left hand threaded bit could back it out.

Good luck!

Ok I might give the left hand bit a shot before notching it with a grinder-- thanks!

 

[Bob Hedgecutter]

If the screw is seized (dissimilar metal corrosion?) and you try to drill a tiny LH drill bit in to a small non flat surface, I can see the bit snapping or spinning out to foul the thread further.
Personally I would be soaking it with penetrating oil and using Mike's suggestion. The frictional heat from the cut off wheel might even help break it loose.

 

[pioneerguy600]

Screw didn't seem to be adjusting or seating/completely closing, then the head fell off so I'm not entirely sure what the situation is. Thanks for mentioning that it might be seized, I didn't think of that. In that case I might be effed on the carb as a whole but I
l'll still try to to get it out cuz oem replacements for the HD-16 seem to be running $150+. The H screw comes out just fine.

I've heard the carb for the 461 works on the 460 after replacing some of the choke linkages. Are there any quality carbs being made at present that will fit a 460? There seems to be no middle ground between $12-20 AM knockoffs and $150+ oem carbs that are out of production.

Several Walbro carbs were used on the 046 and MS460, HD-24C , HD- 14B , HD- 16B , HD-9A and HD-8A.
I would find one of those carb bodies and rebuild it before buying any replacement carb, its what I do every time I get a saw in that needs a carb. I avoid AM ( China) cheap carbs as its too hit and miss if they work or not and the slow shipping time currently sucks.

 

[67L36Driver]

I have a junk carb on the workbench. I was using two sheet rock screws to remove the limiters. Got those off and broke off the low side attempting to turn it back out. [emoji37]

**** happens.

 

[mike-s]

If you Google "walbro hd16", you'll quickly find a $30 (+shipping) used one. Myself, I'd go that way (+rebuild kit) to get the saw running, and then do whatever at your leisure to try and fix what you have, which seems to be an iffy proposition. Drilling steel out of soft metal is a crap shoot, and the head breaking off says it's going to need a (relative) lot of torque to remove the stub. Best case, if you can get it out cleanly you'll have a spare. Worst case, you'll have one you can tear down further for parts.

Separately, as far as the cheap clones, you take your chances. But, it seems worth it to pay $15 to take a shot at having a spare, especially if you have a running saw. Put in the cheapie, adjust and confirm it works (exchange if it doesn't), then put it on the shelf as a spare. If nothing else, if there's a problem down the road, you can swap it in as a quick check whether it's a carb issue.

 

[ChipChomper]

Thanks for the help! This gives me a number of options to try.

 

[ChipChomper]

Several Walbro carbs were used on the 046 and MS460, HD-24C , HD- 14B , HD- 16B , HD-9A and HD-8A.
I would find one of those carb bodies and rebuild it before buying any replacement carb, its what I do every time I get a saw in that needs a carb. I avoid AM ( China) cheap carbs as its too hit and miss if they work or not and the slow shipping time currently sucks.

Thanks for putting together a list-- this is very helpful

 

[pioneerguy600]

Here is a link to a supplier I often get parts from, he has a HD 16B in good condition.
https://store.chainsawr.com/product...hd-16-carburetor?_pos=10&_sid=1bb57c25d&_ss=r

 

[ChipChomper]

Here is a link to a supplier I often get parts from, he has a HD 16B in good condition.
https://store.chainsawr.com/product...hd-16-carburetor?_pos=10&_sid=1bb57c25d&_ss=r

Thanks!