Hey, I've got an old murray pushmower with the classic briggs engine and the fuel tank with the plastic carb on top and the pulsa primer button thing. Last time I had an issue with the primer not sucking in fuel there was a small hole in the primer bulb which I replaced so this time I am having the problem I just replaced the primer bulb which didn't help. What are other reasons the primer bulb wouldn't be sucking in fuel? Do I need to replace the carb diaphragm? That two piece part no. 795083 gasket looking thing? I took everything apart and cleaned it with carb cleaner just hoping that when it all went back together it would work but it is not. I'm thinking I just should go ahead and replace the diaphragm but wondering what else I could do to troubleshoot this. THx!
Old Murray Lawnmower with the Briggs fuel/carb pulsa prime setup not sucking in fuel
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I would be replacing the diaphragm and gasket, making sure that you inst them in the correct order. Diaphragm must be on tank top, then gasket, then carb. Failure to do this will not allow the diaphragm to pump properly. If you need more help or a service manual, post back with all engine numbers.
Thx. Ordered from the amazon and waiting. Was hoping I could have cobbled it back together to get it running today but guess I’ll just be patient. It’s a 22” push model 10A902 2291 B1 with a model 90000 engine not sure how to tell what series but probably just classic 450 all the stickers are worn off.
Hopefully you still have the o-ring seal and retainer which seals the carb to the intake manifold. If missing or the o-ring is bad, it would cause an air leak and very hard starting condition.
Those are still there. I took them out and cleaned them and put them back. The o ring seemed fine but who knows. Guess after i replace the diaphragm i’ll see if something else needs replacing. I have some o ring lubricant stuff from my homebrew gear maybe i will put a little of that on it.
If the diaphragm and more carb cleaning doesn't fix this, is there a better way to check where I might have an air leak other than throwing more parts at the thing like spraying everything with soapy water and pressing the primer bulb or something? Feel like I'm just making best guesses here.
Here is a manual for your engine. After installing the new diaphragm, if it does not start when priming, spray carb cleaner into the air horn and see if it will start. If it starts you may still have a problem with the primer bulb. https://drive.google.com/file/d/0B6NaqjIxWV1ycG8wd0s3Z2Q2X00/view
Ok fellaz. Replaced the diaphragm/gasket, cleaned the carb and gas tank up real sparkly and it started up first pull although smoked out and died and then started up second pull and maintained. Now, I don't know when this thing was tuned up last so I've probably been using it running like crap, it sounded as though it was running at a much higher RPM and am wondering if that is just because I cleaned carb and replaced gaskets and air filters and what not or if the idle switch thingy is set to high or something? I'm attaching a pic, wondering if someone might be able to tell me if it looks set how it should be. Also, is it normal after doing all this work on the machine to have some oily smoke being burn't off on start? Probably should change the oil now once I get this set.
You have a fixed speed setup. That part in the circle, with the spring attached, sets your speed. If you push in on that arm the engine will slow down. Pulling out will speed up the engine. RPMs on that engines should be roughly 3200.