25 hp carb problem HELP!!

I really need some advice on this-I posted earlier, with no responses, about my 1998 4 stroke 25 hp yamaha that appears to be missing the ball in the carb under the plunger/spring in the bowl. The dealer tells me it is a crucial component that lets it idle pefectly, run great on a slight turn of the throttle, then cuts out terribly until backed off, then fine again indefinately. I have put a carb kit in,cleaned several times, all else is fine in the motor with less than 30 hrs, had a mechanic friend go over all specs otherwise and says it's like new. One mechanic says they eliminated this ball in later models because it doesn't matter, the other dealer says it's crucial and I have to buy the whole bowl just to get the little ball @ over 150$. I have tried to find a used "ball" to no avail, does anyone know if I can use a bearing or something else--I am desperate for suggestions before I shell out 150$ to not know if it'll even work or not...please give an opinion...

Re: 25 hp carb problem HELP!!

I looked at the breakdown on that carb and it shows no ball. I have to assume it's a check ball for an accelerator pump. The Yamaha diagram doesn't show one, so I looked at the Merc breakdown (they used Yamaha powerheads on their 4-stroke 25) and it has the accelerator pump, but doesn't show the ball, leading me to believe it's only available with the bowl as an assembly. You might try getting the carb rebuild kit. Merc's number is 854256. It may be included. Without that ball, that carb can't operate correctly. You can substitute a ball of similar size, but I have no idea what that is. Good luck.<br /><br />I should also mention that the Yamaha diagram didn't show an accelerator pump, but it did show a bowl configured to accomidate one. Maybe Yamaha didn't use it on theirs? If not, maybe you can just plug the hole where it goes.