2001 90Hp Saltwater carburetor & idle settings

[theonlyrobertson]

I have found bits and pieces of this topic in here but not a fully detailed one. I have factory manual on order, but would like to set this correct right away so any input will be helpful.<br /><br />I have initially set the carbs as follows:<br />Upper: 3/4 turn.<br />Middle/Lower: 1-1/2 turns.<br /><br />How do I fine tune these settings?<br /><br />I checked the cam/follower on the carb linkage. It has about .007" clearance.<br /><br />Question # 1.<br />I'm not sure the purpose of the white line is since the follower rotates freely on the shaft at idle. What is this for and how is it used?<br /><br />Question # 2.<br />Something I have not seen in the forum is a discussion of the idle screw (it has a big label on it). It has a white plastic cap on the head of the screw to make it easy to adjust with your fingers and it appears to move the lingage that connects to what I think is the timing advance under the flywheel. What is the proper adjustment for this?<br /><br />Thanks,<br /><br />Dale

 

[bryanredfish]

Re: 2001 90Hp Saltwater carburetor & idle settings

I have the same motor -- been fantastic so far. I would wait until you have your factory manual, as these things are VERY sensitive. Also, be careful when adusting the idle -- it is done with the timing adjustment. The high speed jet, is fixed, only the idle mixture can be adjusted. Here's from the manual:<br /><br />While running and in water "shift outboard into forward gear. Turn low speed mixture "in" until otboard starts to bog down and misfire. Turn mixture screw out 1/4 turn our more."<br /><br />If you've had major carb work done, open low speed jets as follows: 1 turn on #1 carb, and 1 1/2 on #2 and 3. This will get it started. Then work your way back.<br /><br />The white plastic cap thing you're referring to adjusts the idle timing, not RPM speed. You'll have to use a timing light -- don't touch without. Timing should be at 6 BTDC.<br /><br />You'll have to be more specific on Question #1.

 

[theonlyrobertson]

Re: 2001 90Hp Saltwater carburetor & idle settings

Thanks for the reply. Question #1 refers to the linkage that controls all the carbs. There's a follower that rotates on the face of the mechanism that is driven by the throttle cable. The follower has a white line through it as does the plate that acts against it. It appears to be something that this is used for checking throttle position.<br /><br />As for setting the timing, does any timing light work to set this? I have messed with that screw setting so now I need to reset it.<br /><br />Thanks,<br /><br />Dale

 

[bryanredfish]

Re: 2001 90Hp Saltwater carburetor & idle settings

Any timing light should work. Disconnect all spark plug wires. Time with the starter motor only.

 

[theonlyrobertson]

Re: 2001 90Hp Saltwater carburetor & idle settings

One thing that has confused me is adjustments after the initial carb settings. Is each individual screw turned in until it misfires and then set or do you have to turn each screw a little at a time until it misfires and then set all three.<br /><br />--Dale

 

[bryanredfish]

Re: 2001 90Hp Saltwater carburetor & idle settings

Turn the screws in (not while running) then back off 1 turn on #1 carb, and 1 1/2 on #2 and 3. Use this as the baseline. This gets them running somewhat evenly. At idle speed in forward gear, work each one in individually until a bog, then back out 1/4 turn or more. Do each one individually. If anything, go slightly rich on the adjustment -- DO NOT go lean.<br /><br />I don't mean to sound like a jerk, but I'd suggest you wait on your manual. ALL of the information can be found there.

 

[theonlyrobertson]

Re: 2001 90Hp Saltwater carburetor & idle settings

I hear ya on the manual, but my 12 year old daughter is having a party this Saturday and I didn't want to disappoint by not having the boat running. I ordered it over a week ago so maybe it will be here this week.<br /><br />Thanks for the help.<br /><br />--Dale