Idle jets.

[steviecops]

Hi, can somebody please help as I'm confused about what the idle jets in my carbs actually do.<br /><br />I have a 1980 Johnson 55. j55EL80C. I recently rebuilt my carbs, and I noticed that the idle jets were sized #48. In my manual, it says that the original jets were #45, but these caused a lean condition at idle, so they changed them to #46 and suggested that anyone with the #45 idle jets, change them to #46.<br /><br />My engine has never idled great, and I thought that maybe the bigger than usual, (#48), idle jets might be flooding the engine out at idle. Then last week I read a post on here stating that the idle jets meter air and not fuel! So if that is right, the larger jets would be making my motor run leaner at idle. In that case, I should fit smaller idle jets.<br /><br />Could someone please clear up this confusion?<br /><br />Thanks in advance<br />Steve

 

[ob]

Re: Idle jets.

I believe you have it right .046 - .048 orifices on a 55hp are idle air jets.I recommend installing the .046's that are recommended and go from there.

 

[steviecops]

Re: Idle jets.

Thanks OB, I'll certainly fit the .046 jets that are recommended. Although my manual says that the bigger orifice jet was to cure a lean condition! Strange!

 

[bubbakat]

Re: Idle jets.

Yes go one size higher then manufactures specs. I had the same problem and mine calls for 27 i put 30 and was dumping to much fuel in at idle. went back with 28 and now idles perfect and accelerates great

 

[steviecops]

Re: Idle jets.

Thats what I was thinking Bubbacat, but apparently the opposite is true. The larger the orifice, the less fuel you are dumping in there!

 

[BillP]

Re: Idle jets.

The problem may not be jetting. I had this problem on a Johnson 140 and it was a thermostat letting the motor run too cold at idle.