No throttle on yamaha outboard!

[bradford35]

Hello all! I am a brand new member to your site. My yamaha has been pretty good to me so i really have not had to do much to her to keep her going strong. Nor am i a boat mechanic so i dont have a lot to share to about motors. I have a 1989 Yamaha 70hp. Last year ran fine with no issues. This year it seems to have little to no throttle in gear. If you pull up the idle lever in neutral it revs fine, as soon as u shift into gear the motor wont go beyond 2000 rpm. Its almost like when have backpressure it wont go faster than 2000rpm but if rev in neutral it is normal. Any ideas would be greatly appreciated. Thanks all and have a wonderful day.

[boats.net]

Run a compression test, check for spark on all cylinders, may need to remove and clean carbs.

[bradford35]

Thanks for the response, also gonna try fuel filter and some stabil in gas. I used my snowmobile gas for the first fillup but forgot to stabil it. Will let u know how it turns out. Any other ideas would be great. Also would like to say that it fires up fine and idles fine.

[bumperfood]

If you have removed the oiling system and are running a premix of 50:1, you may actually restrict the exhaust flow through the engine, because of a buildup of carbon and oil in the exhaust. This usually only happens if you do a lot of low speed running (*****ing).

[99yam40]

Thanks for the response, also gonna try fuel filter and some stabil in gas. I used my snowmobile gas for the first fillup but forgot to stabil it. Will let u know how it turns out. Any other ideas would be great. Also would like to say that it fires up fine and idles fine.

Adding stuff to bad fuel and filtering it will not fix plugged jets/passages in carbs. Keep running it to see if it gets better can and will toast pistons and cylinder walls, if it is running lean.

Need to test things like he said to make sure the motor is sealing properly and sparking on all cylinders.
Check timing to see if it is advancing like it should at problem RPM and make sure you alarm system is functioning. Motor limits RPM to about 2K if alarm system comes in.

[arny]

My guess is clogged carb. jets. Typically behaviour.
Clean your carbs and jets(all) properly.

[darinsray]

my throttle wont shift out of low on my precision blend 40hp

i just recently cleaned all carbs and lines and got my engine running. and it sounds to be running good but when i switch the engine into high gear it just stays in low and the throttle arm bar doesnt move at all. there is a black electric
box right next to the rod that appears to be what controls it, any ideas what may be keeping my boat from shifting into high gear? thanks ,
new boat owner darin

[darinsray]

it goes into reverse and forward np but it just doesnt rise RPMs

[Army Grunt E6]

Sounds like water in carbs....try draining carbs...

[darinsray]

i did drain the carbs and removed them and dipped them. they should be very clean, i followed it up with blowing them out with the air compressor. could my boat be in slow mode? the electric throttle box doesnt move the throttle lever at all. im take a pic and post brb

[darinsray]

see if this works. you see the throttle arm rest againt the black arm from the electric box above. when i shift into high from low it does nothing. maybe my console hand shifter is going bad or else its in slow mode and im not gettting enough water in with water ears on it. but when i take it out it still wont shift up