Starts right up on ear muffs but hard to start in the water

[blackrider]

I have a 1989 Wellcraft 170 Classic. She has a 3.0 L mecruiser S/N C387444. Outdrive is an Alpha One Generation I S/N
0C491501 and I am only in freshwater.

As the title states, anytime I have the boat in the water, it is hard to start and she idles rough. However, when I am in my driveway and using water muffs she cranks right over almost instantly and idles great. This isn't some fluke that just happened once. I have Had her in the water now for 6 different days and each time I launch I have to choke her and crank quite a bit for her to start. But each time I come home frustrated by the behavior, I hook up the muffs to work on it and BAM she fires right up and idles good. I feel like I am chasing gremlins.

The boat in the river is hard to start and idles rough no matter water the engine temp is. On the muffs, she fires right up no matter what the engine temp is also.

Any ideas? Anything????

 

[Don S]

Re: Starts right up on ear muffs but hard to start in the water

Sounds to me like the timing is way off.
3.0L engines seldom start cold and idle smooth on muffs. When they do the timing is way off.

When was the last time you did a full tuneup, new point and condenser, set the dwell then the timing?

 

[blackrider]

Re: Starts right up on ear muffs but hard to start in the water

Sounds to me like the timing is way off.
3.0L engines seldom start cold and idle smooth on muffs. When they do the timing is way off.

When was the last time you did a full tuneup, new point and condenser, set the dwell then the timing?

I did all of this last year for the guy I bought the boat from when he owned it. I used the instructions and info on this site to do it all. The only thing I didn't do was check the timing because I don't have a timing light. I dind't think it was neccessary to check the timing since it was idling very rough and once I rebuilt the carb and all of the above mentioned replacements it ran really good.

But why would it idle rough and be hard to start in the river and run fine on muffs? Just doesn't make sense even if there was a timing issue, woulnd't it present itself in both scenarios?