Mower backfire, Im knee deep in 10 acres of grass,,, my mc 25p48st is backfiring continuously. ive pulled the covers off and cleaned out carb and filters, I thought maybe mixture screw but alf a turn eiter direction did nothelp,, Is there a vacuum line im missing or something,,

SOURCE: Roomba 400 had no manual with it or maybe i misplaced it.

You should be able to find and download the manual for your IRobot Roomba from this site: http://homesupport.irobot.com/cgi-bin/irobot_homesupport.cfg/php/enduser/std_adp.php?p_faqid=46&p_created=1153496340&p_sid=5dXQ9ZRi&p_accessibility=&p_redirect=&p_lva=&p_sp=cF9zcmNoPSZwX3NvcnRfYnk9JnBfZ3JpZHNvcnQ9JnBfcm93X2NudD0xOCZwX3Byb2RzPSZwX2NhdHM9MjUyJnBfcHY9JnBfY3Y9MS4yNTImcF9zZWFyY2hfdHlwZT1hbnN3ZXJzLnNlYXJjaF9ubCZwX3BhZ2U9MQ**&p_li=&p_topview=1

Good luck!
36YearVet

SOURCE: Motor overheating

There is a filter on top of the motor as well. You will need to remove the plastic cover on top of the motor with a small screwdriver or other flat blade. On the front, you push in the clip and pull up ont he cover. On each side of the cover there is another clip - to pop those you put your flat blade into the angled tab and slide it around to the clip until it pops. Gently or you'll break the tab. Once the cover is off there is a purple tab in the center pull up and you will pull the HEPA motor filter out - similar in shape and size to the side, washable, filters. Clean or replace that.

SOURCE: My vacuum cleaner has gotten extremeley loud and....

what kind of vacuum is it

SOURCE: same thing, brushes dont spin unless vacuum is tilted back

I had the same problem. Checked the belt, pulled out all the hairs, cleaned the hoses, but the agitator brush wouldn't spin at all or only marginally. Finally I removed the agitator brush altogether and found crud and accumulated in the small groove at the ends, creating friction. I cleaned it with a small knife (not the most technical of tools, but the only thing small enough I could find to fit in there, especially since it seems there's no way to pop off the end caps and clean them properly). This seems to have solved the problem for now...although I still can't seem to clean it enough to get that same 'pull' back. Good enough to clean up after three black dogs, though, since NOT vacuuming is NOT an option.

SOURCE: Panasonic Vacuum MC-E450UK

Panasonic MC-E 450UK upright vacuum cleaner.
Just had this problem myself...........easy to get at it when you know how.
Panasonic UK wouldn't help me so I spent some time working it out..........here it is.
Remove the hose from its mounting storage at the rear (called hose clip) where the main body of the vacuum cleaner meets the base of the handle assembly. Remove the screw at the rear of the handle assembly which is behind where the hose 'was' situated and is located inside the deep recess.
Using the soft part of your clenched hand as a hammer, knock the base of the handle assembly at the front and it will slide backwards off the main body of the vacuum cleaner. Don't be scared, give it a thump and keep moving it backwards with a few more knocks.
Next remove the two screws at the front which hold the mains cable and on/off switch cover in place.
Finally looking from the rear once more, lift the plastic 'lug' at the top of the cover and which is part of the cover. This will now allow you to release the cover and pull it forward.
There you go! Told you it was easy!
Watch out for the funny little spring at the front behind the cover in the tiny plastic tube where it connects to the small rubber tubing as it could possibly try to escape.
You now have complete access in order to cut the intermittent part of the cable out and remove it from the 'choc' block.
Happy fixing!!
Jack.