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00 Foreman 450 Primer Spray When Revved?

751 Views 2 Replies 1 Participant Last post by  rtmillerx
I am a little stumped on this one- but I dont know the carburetor air/fuel circuit very well
I have a 00 Foreman 450 that will spray fuel out the Primer spraybar just inside the throat of the carb when you rev it up
I have seen this happen once before on a 350 Rancher that I had, but it quit doing it the following year so I never figured it out
It has to be something simple(or not haha)
If anyone can lend some advice on what where to start checking much appreciated
Thanks in advace
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Progress so far---

Switched carbs, problem goes away
Put original carb back on -still pulls a spray out of primer bar when revved
removed primer pump, gas drained ou,t carb runs fine and does NOT pull
thru spraybay (obviously as there is no gas in primer inlet/outlet where the pump mounts)
So, I wonder if there might be a weak spring in the one way ball valve behind the primer inlet
Next move will be to swap float bowl/primer assembly and isolate fault to either carb body/passage way
or the float bowl/primer assembly
Will keep you updated
Appreciate any ideas/help or comments
DONE issued resolved

For those of you that wish to know, it ended up being the primer pump
It had a crack on the interior washer the rides on the spring that-somehow- was allowing the engine vacuum to draw gas
through the oneway valve and out the primer spraybar causing a rich condition when revving
While I cant fully explain as to why or how that causes it, I swapped back and forth several times successfully
When I put the primer pump with the cracked washer on it runs rich and draws fuel
and when I put the known good one on it stops drawing after all the fuel is drawn from the little holding area where the spring for the plunger is
So I hope this can help someone in the future
If you need pics or clarification let me know
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