I am getting a failure rate on these carbs and I don't know why. Some just will not work after cleaning and a new kit fitted. I had a motor yesterday that I had 3 carbs in a row that had exactly the same problem with a pulsing/fluttering/ won't rev motor and I was thinking it must be a valve problem. Fitted the 4 carb and it runs fine. On the 4 one I fitted the kit from the 3rd one and it runs well so it is not a kit problem, there must be something I am not getting clean or something I am not spotting. Any thoughts?
Some those newer carburetor the removable nozzle have metal jet that gets loose. So loose at times they fall out. The old version of the nozzle was all plastic other than the rubber o-ring. and yes they are easily warped by over tightening the mounting screws or just from heat.
I will try to find images of the differences provided I haven't lost them due computer crashes later today when I go to the shop.
Hi AVB, I have one of those carbs with the metal jet but I don't think it has been drilled down the center, can't spray carby cleaner through it and can't put a wire through it. I fitted a plastic jet in that carb but from memory it didn't work, can't remember what happened with it. I usually just keep mixing and matching bodies and gaskets/diaphragms till I get one that works. Isn't very scientific but in the end I get a result, just would like to know if there is some accurate way of testing the carb bodies so I can throw out any that are no good so I don't keep going back over them. Thanks speedy for the vid but I fell asleep
For someone like me who has pulled quite a few of these carbys apart and cleaned them out also replacing the diaphragm but never really understood how the diaphragm worked as a fuel pump. Thanks for the posting well worth watching. The biggest headache with Briggs motors on mowers is the different set ups with the springs, I have been collecting mowers for a mens shed (donated) and quite a few come from the home handyman mechanic who pulls them apart and then gives up and buys a new one, so when I get them most have no springs or the springs in all sorts of ways to be connected. Tries the patience at times, some of these mowers are not that old. I have a Masport at the moment which would have been making one hell of a lot of noise when running, so the carby was removed and refitted (not cleaned) springs not fitted properly, and when it would not start I suppose a new one was purchased. The noise turned out to be the cutting disc cracked all around the mounting and had been flogging for a while, yet to get a replacement, will await a donor mower, I dont think the oil had been changed since new and the blades had been sharpened to the point they were only half as long as they should be. These owners are good for the Mens Shed. Beech
For someone like me who has pulled quite a few of these carbys apart and cleaned them out also replacing the diaphragm but never really understood how the diaphragm worked as a fuel pump. Thanks for the posting well worth watching. The biggest headache with Briggs motors on mowers is the different set ups with the springs, I have been collecting mowers for a mens shed (donated) and quite a few come from the home handyman mechanic who pulls them apart and then gives up and buys a new one, so when I get them most have no springs or the springs in all sorts of ways to be connected. Tries the patience at times, some of these mowers are not that old. I have a Masport at the moment which would have been making one hell of a lot of noise when running, so the carby was removed and refitted (not cleaned) springs not fitted properly, and when it would not start I suppose a new one was purchased. The noise turned out to be the cutting disc cracked all around the mounting and had been flogging for a while, yet to get a replacement, will await a donor mower, I dont think the oil had been changed since new and the blades had been sharpened to the point they were only half as long as they should be. These owners are good for the Mens Shed. Beech
With the masport, if its a 4 blade with a swoopy shaped blade disc, they are known for parting company - sometimes spectacularly with a sheared crank. There was a recall and a reinforcing ring added.
Problem is, often they also crack the deck due to vibration over prolonged period.
