1986 Mercury XR2 Blackmax wont stay running after restart

[Nick596]

Hi Everybody first post here and hoping for some advice on an issue im having with my 1986 Mercury XR2 Blackmax 150 I have on my Ranger 373-V. Ive done just about all the maintenance possible, new boysen reeds, cleaned carbs, new fuel lines (not vacuum lines), oiler delete (mixed fuel at 50:1), spark plugs, and all timing check and adjusted along with a link n sync. The boat fires right up and runs strong, no issues at all moving spots while on the water until its time to come in and put it on the trailer. It will run strong and idle all the way to the ramp, I shut it down to go get the trailer and when it comes time to restart to trailer the boat its hard to start and will not idle until I give it gas and clear it out typically accompanied by 2-3 restarts. Any pointers on what to check to remedy this issue would be appreciated!

[JOE54]

float levels ,carbs flooding , bleed restrictors ,pump diaphragm for starters

[Nick596]

Float levels I reset when I cleaned out the carbs and the pump has fresh diaphrams. Bleed restrictors I am not aware of, do you have any more information on what to look for and how to test their functionality?

[leonreno]

What’s different from stoping to fish and stopping to get trailer? My guess would be you stay at a fishing spot longer than you do at the ramp? So the difference would be short interval between starting. Do you normally pump your bulb when restarting at anytime? The motor at the ramp maybe just hot and vaporizing fuel in lines causing hard starts, pumping bulb will help. Also check the enricher circuit, make sure it’s not leaking and working properly.
I also believe there a heat activated valve that changes enrichment based on temp, may need checking too.

[EuropeanAM]

Did you verify there are no DIMPLES or WEAR POINTS on the tank of each float (where it contacts the needle to close it)?

Engine at LEVEL TRIM, primer bulb pumped firm before EVERY startup?

[Nick596]

Youre absolutely right on the time at the ramp vs the time at a fishing spot, I typically pump the bulb before the first start and never touch it after that. I will check the enricher for any signs of leaking and check the bulb for firmness/pump it before restarting at the ramp my next outing.

[Nick596]

Did you verify there are no DIMPLES or WEAR POINTS on the tank of each float (where it contacts the needle to close it)?

Engine at LEVEL TRIM, primer bulb pumped firm before EVERY startup?

I cannot say that I inspected the floats for any wear but I did replace every needle and seat when I did my overhaul. I typically only pump the primer bulb before my first start of the day and never found it necessary re-starting on the water.

[EuropeanAM]

Level trim and utilizing the primer bulb before every start definitely helps with starting and idle quality.

Unless a float is improperly set- I would suspect there may be wear points on one or more float tangs (which can skew the needle in the seat sometimes).

[Nick596]

Level trim and utilizing the primer bulb before every start definitely helps with starting and idle quality.

Unless a float is improperly set- I would suspect there may be wear points on one or more float tangs (which can skew the needle in the seat sometimes).

I am going to pull the carbs off and inspect the floats again, what is your recommended method for setting the floats? Ive heard level with the body and 1/16" above which is what I did.

[EuropeanAM]

I've found that using the level recommended in the Factory Service Manual (for a specific model/carb) usually produces the best results.