My JD has a double bagger. After emptying it, it continued to cut but wouldn't throw the grass in the bags.its not clogged,is there something I missed or have to do when I put the bags back on

Check all areas where the grass gets sucked or thrown such as the areas under the mower. Sounds like it could be plugged some place.
Check your blades also and see if they are working properly.

Is this a centre rear discharge mower, if so has the mulch plug been left in? if so this will block the outlet chute, most mowers are fairly simple in as much as the blade cuts the grass and the wings on the blade tips create a draught to send the cut grass into the bag, any blockage in the chute will stop the grass being sent into the bag, insufficient engine rpm will also effect bagging, wet grass will tend to block the chute as well.

grass catchers need special shaped or good blades to throw the cut grass into the bag
check/ replace the blades

Yes. I use gator mulching blades during the summer. They won't bag a thing. The original/standard blades will bag some grass/leaves, if they are dry and not too dense, but they are prone to clogging. The high lifts work much much better.

I get mine on amazon. The shipping is free. LA145 48" deck. Part GX21785.
http://www.amazon.com/gp/product/B00CAXMAG2/ref=oh_aui_detailpage_o07_s00?ie=UTF8&psc=1#product-description-iframe

ive got a JD 180 .with a bagger on it if you have the factory bagger
1st bolt bracket to back right hand side of tractor holes should allready be there next assemble bagger top to tractor bracket , hang collection bags (two) from top of bracket (open top to access) then assemble diverter tube all together three sections , snap end (wide) into bagger (no bolts needed) then fold back safety discharge cover on deck all the way snap the inlet adaptor into hole left by this (perfect fit) and last stretch rubber bungee up to deck wheel strut and place clip thru small moon clip there, now you willl need to replace your deck blades with the High Lift type (mulch) avail still from JD (theres a extra wing on back of it) this makes more air to scoot grass up the chute if not your gonna have a lot of cloggs

Blades cut the grass and blow air like a fan. The clippings should flow along with the air out into the yard or into the bag. That only works if the bag acts like a filter and catches the clippings but lets the air out to be replaced by more air and more clippings until the bag is full of clippings.
The most likely problem is that your bag does not let the air out. Cutting wet grass will coat the inside like green paint. When dry, it's like the underside of your mower.
Check the inside. You might need to scrape and/or flush from the outside in. Can yours be turned inside out"? That would be the best case.
When clean and dry, it should work.
Didn't mention the easiest fix: to take out the hand-ful of clipping blocking the path to the bad: since you already checked that.

Inspect the inside surface of the discharge tube. If you do not find any hangups, then I would wonder how fast you are mowing. If you are going full speed, I would recommend that you slow just a little. I was just thinking, have you been doing the same thing for a long time and recently have this problem develop. So, give good inspection. I do not know what type of bagger you have, but is the air able to escape the bagger, if it is not then it sets you up for a clog. If you can not find anything on detailed inspection of bagger system, there are sprays for under the deck of lawnmowers to minimize the chance of grass clinging to the underside of decks, you could try applying that to the ducting of your bagger. I hope this is helpful.

The MTD web site has a list of items to check:

http://support.mtdproducts.com/cgi-bin/mtd.cfg/php/enduser/std_adp.php?p_faqid=68&p_created=1027017166&p_sid=tq2XafGj&p_accessibility=0&p_redirect=&p_lva=214&p_sp=cF9zcmNoPTEmcF9zb3J0X2J5PSZwX2dyaWRzb3J0PSZwX3Jvd19jbnQ9MTQsMTQmcF9wcm9kcz0wJnBfY2F0cz0wJnBfcHY9JnBfY3Y9JnBfcGFnZT0xJnBfc2VhcmNoX3RleHQ9YmFnZ2VyIGNsb2dz&p_li=&p_topview=1

Hello monica_skinn:

If the Underside of the Deck is Clean and the Blades are Tightened Properly, then the Problem is Caused by the Blade Lifts being Worn or the Blades are Not a High Lift (Bagger Blade) Blades.
A Bagger Blade has a Very High Lift Ear on the Backside of the Blade Across from the Cutting Edge. This Extra Lift is What Gives the Extra Lift and Throw (by increasing air Flow under the Mower) the Grass gets to be Bagged.
Please, Do Not Hesitate, If you Hit a Snag or this Does Not Correct the Problem, I am Here if You Require More Assistance.
Hope this Helps. Let me Know What Happens, Please. May the All Mighty Bless You and Yours. Be Safe and Be Happy. Thanks.

Good Luck

Respectfully

jbridger (John)

the grass is too high, cut it 2 times first cut should be half then the second cut should be the normal level. just remember go the other way on the second cut.