Re: 1974 70 hp idle problems
I pulled the carbs off and went thru them again and it ran a bit better at idle but still not right. So I bought a 1978 70 to use the downhousing and power trim, the 74 powerhead is on that downhousing. I thought I would rebuild the carbs off that motor and did, they are different in the fact that they have a little tube in the middle of the venturi tube and have only 2 jets that I can find. One jet is the big jet in the bowl and the other is the air jet for idle, whereas the 74 carbs had a additional jet between the bowl and carb and no little tube in the venturi. Anyways I soaked the carbs and rebuilt them and they ran horrible, bogging out at all speeds except above 1700 they ran fine. I got scared of burning a piston so I resoaked my old carbs and went thru them again and it runs much better on the flusher but it got dark so I could not run it at the lake. I am now a 100% expert at taking carbs on and off a 3 cyl OMC. I will see tommorrow how it runs. If it does not run right then I have to say it will have to be another problem as I know the carbs are clean. Could it be either a fuel pump or reeds. The fuel pump I had ruled out because it ran good above 1200 but now I am thinking that if the diaprhams were bad they would not function well at low speed. I know nothing about reeds so do not know what they cause. I do no that with my original carbs and the boat on the trailer that at wide open throttle the carbs spit fuel out the front but the engine would only turn up 2400 on the trailer so I assumed that without rpms the carbs were dumping to much fuel for the engine to intake. I will follow up tommorrow with the results. Heres hoping for a good idle.
