09Searay175
Recruit
- Joined
- Nov 11, 2013
- Messages
- 4
I have a 2009 Sea Ray 175 with a Merc 3.0L that has a TKS carb. Over the past two years I've been dealing with carb issues and having to rebuild it each season due to fuel contamination. I’ve since added a 10 micro fuel water separator and the boat is running much better now.
I had someone else rebuild the carb last go around as I was tied up with work. For this rebuild the plug guarding the idle mixture screw was removed
. While this was helpful, the rebuilding had initial setting to lean at the factory spec. It wouldn’t idle well when at operating temp and would sputter and die after running at 750 rpm for a few minutes. It would also diesel nearly every time I shut it off. I richened up the idle mixture by about 3/8 of a turn and now the boat will idle smoother, wont sputter and will run at a much lower RPM. The boat is run in TX so it’s pretty hot in the engine compartment during the summer. With 93 octane I have no dieseling on shutdown but still let it idle down a bit before killing in.
I have a question that has always bugged me about the 3.0L. When I start the boat cold the TKS works and fires right up. If I shut the boat off to pick up a tuber it will fire back up with the flick of the key when at operating temp, no throttle is needed. The thing that bugs me the most is that when I’m floating on anchor for 2 two hours and the boat cools off it doesn't want to idle well. The boat will start OK but I have to increase the idle speed a bit to keep it running for 30 seconds or so before backing up the throttle. I don’t think it’s a flooding at idle problem as I don’t have to give it full throttle to start. I just need to run it at a fast idle until it reaches operating temp of 170 ish and then it will idle normal. So is this due to the following?
Thanks,
Shawn
I had someone else rebuild the carb last go around as I was tied up with work. For this rebuild the plug guarding the idle mixture screw was removed
. While this was helpful, the rebuilding had initial setting to lean at the factory spec. It wouldn’t idle well when at operating temp and would sputter and die after running at 750 rpm for a few minutes. It would also diesel nearly every time I shut it off. I richened up the idle mixture by about 3/8 of a turn and now the boat will idle smoother, wont sputter and will run at a much lower RPM. The boat is run in TX so it’s pretty hot in the engine compartment during the summer. With 93 octane I have no dieseling on shutdown but still let it idle down a bit before killing in.I have a question that has always bugged me about the 3.0L. When I start the boat cold the TKS works and fires right up. If I shut the boat off to pick up a tuber it will fire back up with the flick of the key when at operating temp, no throttle is needed. The thing that bugs me the most is that when I’m floating on anchor for 2 two hours and the boat cools off it doesn't want to idle well. The boat will start OK but I have to increase the idle speed a bit to keep it running for 30 seconds or so before backing up the throttle. I don’t think it’s a flooding at idle problem as I don’t have to give it full throttle to start. I just need to run it at a fast idle until it reaches operating temp of 170 ish and then it will idle normal. So is this due to the following?
- Standard characteristic of the 3.0L (which is known to have a rough idle)
- The TKS carb is running the engine to lean regardless of mixture setting (my 89 4.3L with a standard Mercarb never gave me these issues)
- Should I richen the idle mixture a bit more?
- Is this a vapor lock issue in the fuel pump due to lack of air circulation and fuel boil over?
Thanks,
Shawn
