I have Briggs 5 HP, ? , 80832, on a Teel water pump, with a tank mounted carb. It starts and runs, but only runs well with the jet needle all the way closed. It actually runs fine with the jet needle completely removed, leaving an open hole to the main jet. Obviously this engine is running very rich for some reason as if there is an internal leak in the carb allowing too much gas in. Any ideas?