Mercruiser 2011 3.0 TKS issue

MTBGCA

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Jun 30, 2023
Messages
9
Hello,

I've been trying to resolve a warm start problem with my 2011 3.0 TKS. Here is the initial problem: hard start when run until warm (30 min) and then off for a while - hard to start but always starts. Last two times out trying to troubleshoot and now it hardly runs at low RPM, starts okay but need to keep RPM 1,500 to 2,000 to keep it running when warm.

I've done all the troubleshooting in the Merc. #41 service manual. I've bench tested the TKS module last year and it extended as per spec but a little slow. TKS module resistance was to spec. Bench tested the temperature switch and it responds as per spec. Have not been able to check the oil pressure switch when running, checks okay not running.

Had various results when trying to check things when running and when not running when warm.

As a last resort I checked the load on the TKS module by sticking a multi meter in line an found it was drawing about 0.375 Amps consistently. This tells me that the electrical circuit is operating correctly.

I'm planning to pull the TKS unit again tomorrow and check it out again. The only other thing I can think of is to spray carb cleaner into the TKS barrel on the carb.

The only thing I can think of is that the TKS plunder is getting stuck and not closing the fuel supply.

Any ideas as to what is is or what else to do?

Thanks in advance.....
 

alldodge

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Messages
42,059
Check the throat of carb after warned up.
Watch and see if fuel isn't dripping down the throat when OFF
 

MTBGCA

Cadet
Joined
Jun 30, 2023
Messages
9
Hello,

I've been trying to resolve a warm start problem with my 2011 3.0 TKS. Here is the initial problem: hard start when run until warm (30 min) and then off for a while - hard to start but always starts. Last two times out trying to troubleshoot and now it hardly runs at low RPM, starts okay but need to keep RPM 1,500 to 2,000 to keep it running when warm.

I've done all the troubleshooting in the Merc. #41 service manual. I've bench tested the TKS module last year and it extended as per spec but a little slow. TKS module resistance was to spec. Bench tested the temperature switch and it responds as per spec. Have not been able to check the oil pressure switch when running, checks okay not running.

Had various results when trying to check things when running and when not running when warm.

As a last resort I checked the load on the TKS module by sticking a multi meter in line an found it was drawing about 0.375 Amps consistently. This tells me that the electrical circuit is operating correctly.

I'm planning to pull the TKS unit again tomorrow and check it out again. The only other thing I can think of is to spray carb cleaner into the TKS barrel on the carb.

The only thing I can think of is that the TKS plunder is getting stuck and not closing the fuel supply.

Any ideas as to what is is or what else to do?

Thanks in advance.....

Sorry, posted this in the outboard section...

To add, runs great over 3,000 RPM
 

MTBGCA

Cadet
Joined
Jun 30, 2023
Messages
9
Just realized I posted this in the wrong forum. Re-posted in mercruiser forum.

Sorry for the mistake
 

alldodge

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Mar 8, 2009
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42,059
Going to get in a bad place real fast doing multi post
If you post is in the wrong section flag the post and a MOD will move it

I merged all post to the Merc section
 

MTBGCA

Cadet
Joined
Jun 30, 2023
Messages
9
Sorry, it was initially posted in the wrong forum and didn't know how to move it so re-posted it. It will not happen again.

Thanks for the feedback
 

MTBGCA

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Jun 30, 2023
Messages
9
Will check for dripping gas, forgot to do that yesterday.

Thinking of doing a carb rebuild anyway ... thoughts?
 

alldodge

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If it's just the float level is set to high then a change will fix the issue

If you open the carb to check float level and find some crud, then rebuild, otherwise maybe not unless there are other issues
 

MTBGCA

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Jun 30, 2023
Messages
9
Thanks again for the help. I've never worked a carb before but have done lots of mechanical work in the past, for example rebuild my Honda engine many years ago.

If I find gas dripping I assume I should pull the top off the carb and check the float. What do I need to look for / correct. I've read that the floats can get saturated with fuel, I assume pulling the float and weighing it will answer that question.

Once I checked it out I'll post a picture and / or video of what I see.

Any additional advice?
 

MTBGCA

Cadet
Joined
Jun 30, 2023
Messages
9
I forgot to mention that I noticed a oily residue when I pulled the flame arrester off. See picture attached with the area highlighted.
 

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alldodge

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42,059
The oil is of no concern, it should be coming from a hose coming from the valve cover to flame arrestor.

If dripping take top off and measure height. If height is correct then probably needs the needle valve and seat replaced

The float weight might be an issue but in most cases no
 
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