Merc 470 hard to cold start

[jcole59946]

I own 1987 SeaRay 19 foot bowrider powered by the original Mercruiser 470 165 HP 4 cylinder engine. The engine compression is still pretty good with all cylinder between 150 and 135 psi. The carburetor is a MercCarb 2 barrel # 1389954 6403. Recently I had the carburetor rebuilt and the ignition converted from points to electronic ignition using a Sierra electronic conversion Kit # 18-5297. Before the carb and ignition work was done, the engine cold started without much trouble. Now it takes 20 minutes of cranking and frustration to get the motor to run. Once the motor warms up it runs perfectly and idles smoothly. Warm starts are much easier.
The original Mercruiser 470 timing spec on the valve cover is 8 degrees BTDC. The new timing spec in my Clymer manual is 4 degrees BTDC.
My understanding is this adjustment is made to cope with ethanol gasoline.
The mechanic says he set the timing to the new spec.

Do I need to adjust the timing or the carburetor or the choke? How do I make the adjustments?

Thanks

 

[Big Boat Bay Buster]

Re: Merc 470 hard to cold start

If you had a mechanic set this up, you need to get him involved. Sounds like a choke issue. I would pull the flame arrester and observe the choke plate during the cold start. Put throttle in neutral and give it a pump or two. This should allow the choke plate to close and prime the carb. At this point it should start and run---the choke plate will partially open untill warm--then it will be fully open.
This is where I would start.
Chris

 

[CAPTKEV85]

Re: Merc 470 hard to cold start

Ok check your choke make sure she is not stuck closed. If shes stays closed the engine will flodd and run like crap. Also whe I converted to electronic on my 470 I stayed at the factory 8 degrees and I have mallory ign. Boat starts on a half turn.