3.0 TKS will not idle. Requires lots of throttle to start

[H20 Insane]

I dewinterized the boat (09' 175BR) about a month ago, ran it on the muffs and then took it to the river. It started and idles okay, but when I got to open water and started to apply power it would stumble pretty bad around 2k rpms. If I give it a little more gas it will get past the stumble and run great in the higher RPM's. I tried playing with the idle screw adjustment, but it made no difference.

Fast forward to yesterday and I get the boat out for trip #2 of the season with the intentions of fixing this stumble. I launched, let it idle and then got to open water. Same thing happens, so I go about doing larger changes on the idle screw with no results. Eventually the motor wont even start anymore without a good amount of throttle and it absolutely will not idle. I limp it back to the dock and bring it home.

Today I changed the Racor fuel water seperator filter, new AC plugs (gap at .045), set the idle screw to 1.54 turns out, cleaned the fuel filter at the carb inlet (tiny amount of debris) and entirely removed the filter at the fuel pump. Same thing.... idles good when cold, but as it heats up it does not want to run and becomes a bear to start (requires 1/2 throttle to get it fired and 1/4 throttle to keep it running). I think I've narrowed it down to the carb being gummed up. Or does anyone else have an opinion? Runs good til warm and then hits the wall.

I've got no issues rebuilding the carb, but if its a TKS issue and I can fix that without an entire carb rebuild then that would be ideal. Thx!

 

[extremez]

Re: 3.0 TKS will not idle. Requires lots of throttle to start

this is exactly whats been happening with my 3.0L. all i have done at this point is a slight adjustment on my idle screw to keep from stalling out. set to about 800 rpm. i replaced the paper filter under the fuel pump and cleaned out the screen filter at the carb.

started it up this morning and it ran fine for a bit on muffs. shake the boat around a little to simulate some actual use and it seemed ok. it did bog down once when i got the drive moving forward, right around 2000 rpm. just once though.

going out on the lake tomorrow and going to try and burn some fuel off.

i did look down the carb and mine does look gritty on the inside.

keeping open ears for suggestions to your issue as well.

 

[H20 Insane]

Re: 3.0 TKS will not idle. Requires lots of throttle to start

Not too surprisingly it was the carb. I tore it down, cleaned, rebuilt and ran her all day yesterday.

The carb wasn't varnished with old fuel, but it looks like a few particles of contamination got in and plugged up the idle circuit. I bought the Quicksilver $60 carb rebuild kit from West Marine, but only ended up using 2 gaskets and reused all the OEM jets, plunger, etc. as they appear to be superior quality and I'm leery of using unstamped knock-off jets. My motor only has 40hrs and they were all in perfect condition.

I think I could have solved the issue simply by removing the carb top, removing the jets and blowing out the orifices with carb cleaner and then compressed air. And I could have salvaged the top cover gasket and not spent a dime. Oh well.... it was still way cheaper than the shop and a full tune up never hurts. The carb is super easy to work on. Much easier then the Keihin FCR motorcycle carbs I'm more familiar with.

 

[Don S]

Re: 3.0 TKS will not idle. Requires lots of throttle to start

Install a water separating fuel filter in your system as well. The 3.0L engine have never had them from the factory like all the other engines do. And change it yearly. Saves buying those expensive kits.