OutdoorKing Repair Forum Forums Repairs and Maintenance Questions on Engines Questions On Briggs & Stratton Engines Carby bolts coming loose

Same engine as previous thread

Carby keep coming loose after every mow 25min?
Even used some loctite but still came loose, new spring washers may fix this?
Maybe the threads are bit damaged in the head

There seem to be two obvious possibilities. One is that the engine is experiencing an unusual level of vibration. The other is that for one reason or another the thread has become loose, which makes it very difficult to keep bolts tight. Are any other screws and components coming loose?

If the engine is rarely dismantled, I'd suggest putting some loctite on the bolt threads. Don't use one of the exotic high strength versions of the sealant of course - you do want to be able to remove the bolts if necessary. If the machine is dismantled regularly, I'd be inclined to switch to studs and nuts instead of bolts, and anchor the studs in the block with loctite.

Studs is a good idea
No I don't think anything else is coming loose, been using this mower for a while and it's always been the carby bolts

Hi to Perthmower and Grumpy,

I had this problem when I had the Briggs and Stratton fitted, one of the screws fell out on the lawn when I was mowing. I consequently ran over it and took a nick out of one of the cylinder blades and ruined my bedknife.

With re-grinds, the reel in back to normal, and I had a new bedknife ground and fitted just after the incident.
An expensive exercise!

re tap the holes to clean them up and maybe get some new bolts, and some spring washers and that should do the trick

I dont think they are the right bolts, most if not all my my engines similar have slotted heads from at least 2 directions. The spring washer looks flattened, some new washers should do the trick, but if you plan on taking it apart more often studs with spring washers would be best.