Author Topic: Carb Hi and Low Screws keep vibrating loose. (Read 1813 times)

05_sprcrw · « **on:** March 18, 2011, 10:28:40 am »

On that 394xp I just rebuild the carb screws keep vibrating loose after I set them is there anything I can do to keep them in place. The springs are on and still are pushing against the screws with good pressure. Can I use plumbers tape (white thin plastic) to cover the last little bit of the screws to help make a tad tighter fit?

smalldog · « **Reply #1 on:** March 18, 2011, 11:02:49 am »

I have heard that if you remove the screw limiter caps(on newer saws), that you should put them back on because the screws will loosen? If this is a problem, even with the cap on, wouldn't your setting change until it hits the stop? I'm running a ms460 and ms361 with out the caps and haven't had a problem yet, but will I later?

05_sprcrw · « **Reply #2 on:** March 18, 2011, 12:33:12 pm »

I did have the rubber boot taken off so I could set things easier then once it was set I was going to put it back on. Maybe I need to put it back on and see if it will stop it.

smalldog · « **Reply #3 on:** March 18, 2011, 12:58:03 pm »

Would the rubber boot keep the carb from vibrating so much? If you rough up the ends of the spring, would it help keep the screw from turning? I don't think the teflon tape idea would work because it is slippery and it is a straight thread vs a tapered pipe thread. For a LAST resort, I might put a VERY small amount (with a toothpick)of purple locktite on the screw. The purple is a removable thread locker for small screws.

05_sprcrw · « **Reply #4 on:** March 18, 2011, 01:39:16 pm »

It might but I don't think the rubber boot should have that big of an effect on the screws backing out. I will try the roughing up the spring and if that doesn't work the purple loctite. I guess last resort would be to just buy a new carb and hope that the holes are just worn out and not something else.

smalldog · « **Reply #5 on:** March 18, 2011, 01:52:57 pm »

If you only put the thread locker on the screw its self, you will limit getting it where you don't want it.(in the carb)

beenthere · « **Reply #6 on:** March 18, 2011, 02:27:48 pm »

Bubble gum?

05_sprcrw · « **Reply #7 on:** March 18, 2011, 04:52:11 pm »

I would only put thread locker on the last portion so I did not have to worry about it making it into the carb. (in theory)

arojay · « **Reply #8 on:** March 19, 2011, 09:43:39 am »

Maybe you need to replace them.

Smurf · « **Reply #9 on:** March 19, 2011, 09:56:11 am »

The Loctite (removable) thread locker applied to only the last two threads will work very well . I used this application on numerous old chainsaws and motorcycle and snowmobile carburetors jets over the yrs. Just a drop is required , a little goes a long way . A tooth pick can be used as an applicator . The rubber boot on the Older Pioneers did secure jet screws from vibrating out . The rubber of course over the yrs will dry out and not secure the screws as well . Scott on the Chainsawer site has replacement components for various saws . On new saws the caps should be replaced once tuning has been achieved.

05_sprcrw · « **Reply #10 on:** March 20, 2011, 08:48:28 am »

Thank you smurf, I did put that boot back on yesterday and it held its timing it looks like I won't have to do the thread locker just yet but it is good to know that it will work.

Do any of you guys know a good place to pick up a square slotted wrench for the walbro wj 39 carb idle adjustment screw? I have been using needle nose pliers but with the boot on I can not get in there and turn it with them.

Cut4fun · « **Reply #11 on:** March 20, 2011, 02:53:06 pm »

Feebay or do as I do and many other rednecks before me, dremel you a slot in the needle head and then use a screwdriver.

komatsuvarna · « **Reply #12 on:** March 20, 2011, 07:49:25 pm »

I've herd of people putting some RTV silicone over the screws after they were adjusted right. Ive never tried it, but it just might work.

beenthere · « **Reply #13 on:** March 20, 2011, 11:19:34 pm »

That might be better than bubble gum.

05_sprcrw · « **Reply #14 on:** March 21, 2011, 07:51:27 am »

Quote from: Cut4fun on March 20, 2011, 02:53:06 pm

Feebay or do as I do and many other rednecks before me, dremel you a slot in the needle head and then use a screwdriver.

I ended up going the feebay route it was a little over $8 after shipping for the correct tool. I figured why not, I am sure it will come in handy.

John Mc · « **Reply #15 on:** March 21, 2011, 09:18:38 am »

Quote from: 05_sprcrw on March 21, 2011, 07:51:27 am

I ended up going the feebay route it was a little over $8 after shipping for the correct tool. I figured why not, I am sure it will come in handy.

What did you end up searching on to find the correct screwdriver on eBay?

I may add one to my toolbox. I got a great chainsaw multitool from Baileys. It has just about everything I need for "in the field" work (especially since I don't have the skills for major repairs anyway), but it does not have one of these newfangled screwdrivers. None of my saws have the new screws yet, but I figure it's only a matter of time...

John Mc

05_sprcrw · « **Reply #16 on:** March 21, 2011, 11:05:21 am »

Since I have a walbro 39 carb it had a flat (like a flat head screw driver) shape to it but thicker. I started looking around and it is called a "double d" carb adjustment tool is what I ended up looking for you can also type in husqvarna carburetor adjustment tool and it should pop up in that search too.

Here is a link to the one I purchased:
http://cgi.ebay.com/ws/eBayISAPI.dll?ViewItem&item=170607069940&ssPageName=STRK:MEWNX:IT

John Mc · « **Reply #17 on:** March 21, 2011, 12:31:45 pm »

Thanks for the info, 05_sprcrw

I thought the newer Husky saws had a splined screw head (like the one at this link), rather than the "double-D" tool you indicated. I guess I'll have to take a close look when I finally get around to buying a new saw.

John Mc

smalldog · « **Reply #18 on:** March 21, 2011, 12:46:18 pm »

John Mc...that looks just like the Poulan carb tool # 530035560 and it cost me $5.11 several years ago.

John Mc · « **Reply #19 on:** March 21, 2011, 01:55:36 pm »

Quote from: smalldog on March 21, 2011, 12:46:18 pm

John Mc...that looks just like the Poulan carb tool # 530035560

I guess that would make sense... doesn't Husqvarna own Poulan?

Some of the other eBay ads for the same tool list Poulan as one of the saws they fit. The one I posted had one of the better pictures of the business end of the tool.

Cut4fun · « **Reply #20 on:** March 21, 2011, 02:04:30 pm »

The set I know of.

John Mc · « **Reply #21 on:** March 21, 2011, 02:18:55 pm »

What a pain in the rear-end! Why can't they just stick with the standard screw driver? Do they really think that's going to stop someone intent on adjusting the mixture?

I heard someone mention that some size or another of plastic/rubber tubing works well on the splined screws... not that I'm likely to have the right size lying around anyway.

Cut4fun · « **Reply #22 on:** March 21, 2011, 03:07:52 pm »

The D was on my Solo. I just cut slots.

The spline became a pita when doing a bunch over and over with plastic tubing. I broke down and got the spline screwdriver. Saved a lot of time in the end when doing 3-4 poulans in a row.

05_sprcrw · « **Reply #23 on:** March 21, 2011, 04:40:37 pm »

I have now have 3 out of the 4 I am just missing the D set. It sure makes things easier even though like others said you can get by with out it if you want to.

JohnG28 · « **Reply #24 on:** March 21, 2011, 06:40:41 pm »

That's the tool I would need for my little Husqvarna 142. A while back before I realized they couldn't sell this tool I had a dealer recommend using a piece of fuel or impulse line to do the trick if adjustments were needed.

Yoopersaw · « **Reply #25 on:** March 22, 2011, 04:32:29 pm »

Where can I pick up a set of these?

Cut4fun · « **Reply #26 on:** March 23, 2011, 06:46:47 am »

Quote from: Yoopersaw on March 22, 2011, 04:32:29 pm

Where can I pick up a set of these?

FEEbay for the whole set.

05_sprcrw · « **Reply #27 on:** March 23, 2011, 08:09:21 am »

Like someone said ebay you can get the single driver or the complete set very reasonably.

05_sprcrw · « **Reply #28 on:** March 30, 2011, 09:49:32 am »

Well I got the driver in and it is too small for the throttle adjustment on the 394/395 so I am going to end up just making on myself and see how that goes. A pair of long needle nose pliers can probably get in there and turn it with the rubber boot on but I am going to try this more because I can then any other reason.

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Author Topic: Carb Hi and Low Screws keep vibrating loose. (Read 1813 times)