idle adjustment

[countrytn]

I have a 2001 Yamaha 115 TLRZ 2 stroke, the motor runs good but the idle is a little low, around 600 and wants to die when pulling up to a dock,etc. I would like to adjust the idle up just a little but don't know exactly how to do this, anyone know how?

[boscoe99]

Yes. I do. Some others will also know how as well.

[robert graham]

Should be a small Phillips head screw on your throttle linkage.....remove upper cowl and look there while having someone move the throttle and hopefully you'll see the screw....clockwise should raise your RPM's.....Of course there are other things that could cause a low idle, but that screw could be it...

[99yam40]

If the motor has run fine in the past and is now having problems you need to be doing more to it than adjusting the idle speed screw. If someone has been playing with adjustments then a complete look over and setting all back to proper specs following procedures in service manual.

if no one has been tinkering with it then find out what has gone bad and fix that

[countrytn]

no messing with anything other than fuel lines, filters and plugs, it is possible the carbs need rebuilding. I will let the expert handle that

[greasyshaft]

Winding in the idle screw is simply masking another problem.

[robert graham]

Winding in the idle screw is simply masking another problem.

That could very well be....check idle mixture screws/circuits...if one or more has trash/debris in it, can cause idle issues. Idle mixture screws on top of each carb...read up on it before you mess with it...

[rodbolt17]

typically idle speed, like ign timing, once set NEVER changes UNTIL some breaks,wears or gets dirty.
its a mechanical stop and wont move by itself.

[countrytn]

checked the screw that controls idle, no screwdriver needed as I can move it with my fingers? By rodbolts and others that replied this should not turn that easy, so what should I put on it so that it don't turn easily

[TownsendsFJR1300]

checked the screw that controls idle, no screwdriver needed as I can move it with my fingers? By rodbolts and others that replied this should not turn that easy, so what should I put on it so that it don't turn easily

Ther should be a push spring around the screw to keep tension on it..

[bigcountry]

could engine vibration over time cause the bolt to loosen?

[TownsendsFJR1300]

could engine vibration over time cause the bolt to loosen?

If he's talking about the idle screw (the correct screw with the spring), no it shouldn't move..

Almost all carberated engines have that screw/spring (for an idle setting). Most FI engines will use a screw with a spring to sync the throttle body shafts as well,( ie F150, 2 TB's, one torx sync screw with spring in the middle).

My older in line 4 cylinder Yamaha MC, 1300cc , FI'ed, used three similar adjusters (screws with springs to sync the 4 throttle bodies)

The only way it could loosen with the spring is if it was way out of adjustment and the spring wasn't touching (working), then it could vibrate out.