# 2009 yama 70hp 2 stoke Idle



## MMelville (Apr 9, 2019)

PM sent


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## Smackdaddy53 (Dec 31, 2012)

Did it high idle right after cranking up again after it was shut off? They are designed to do that. Let it idle back down before shifting.


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## NativeBone (Aug 16, 2017)

Suddenly high idles after cranking up again. Never happened before. It usually high idles momentarily and then idles down.


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## Plantation (Nov 24, 2015)

I noticed if you happened to remove your thermostat it will high idle way long before idling down. Does it idle down at all? If it takes a long time, but eventually idles down it could be a stuck open thermostat.


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## NativeBone (Aug 16, 2017)

Ok- so, something very interesting happened. When I finally had enough and decided to dock, I started the motor and was expecting the same high idle as before, but instead the motor idled as normal as if nothing at all had happened. What am I missing here. 

@MMelville thanks for your help! I appreciate the troubleshooting while out on the water!

@Plantation I will pull the thermostat and check it.


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## lemaymiami (Feb 9, 2007)

When that sort of stuff happens I suspect a linkage problem. Remove cowling and with motor off have someone advance and return the throttle to get a sense of its range and whether it’s returning to baseline each time. Then start motor on the hose and with gears disengaged advance and return the throttle to see if anything mechanical is at play. If everything works the it’s supposed to, lube each joint in the linkage and plan on a run to the nearest boat ramp for a water test to see if the symptoms recur... If not, keep on running but make a point of mentioning the problem to whoever does you motor work the next time you’re scheduled...


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## Smackdaddy53 (Dec 31, 2012)

NativeBone said:


> Suddenly high idles after cranking up again. Never happened before. It usually high idles momentarily and then idles down.


It is supposed to. I mentioned this in my first post. It’s part of the PrimeStart system.


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## NativeBone (Aug 16, 2017)

Smackdaddy53 said:


> It is supposed to. I mentioned this in my first post. It’s part of the PrimeStart system.


Right! I agree. Perhaps my on the water texting is coming off a little off. What I am saying is the motor is NOT idling down as normal/designed. The high idle doesn't go away regardless how long I let the engine run.


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## Plantation (Nov 24, 2015)

If it was never idling down then probably had nothing to do with the thermostat. It would eventually idle down with it removed, just take longer than usual after it had already been running. Hopefully it doesn't do it again. Now I'm no expert and just a guess, but sounds like the needle in the primestart was maybe stuck up, or some issue with that Yami choke system. But do check the throttle linkage as well.


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## Smackdaddy53 (Dec 31, 2012)

Plantation said:


> If it was never idling down then probably had nothing to do with the thermostat. It would eventually idle down with it removed, just take longer than usual after it had already been running. Hopefully it doesn't do it again. Now I'm no expert and just a guess, but sounds like the needle in the primestart was maybe stuck up, or some issue with that Yami choke system. But do check the throttle linkage as well.


I concur


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## markp1958 (Jan 11, 2021)

That's a gem of a motor hope you can get it straightened out.


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## NativeBone (Aug 16, 2017)

UPDATE: So far the motor idles as designed and has not repeated the unusual high idle it once did. So what should I look for? My experience tells me this will ultimately happen again. Problems rarely take care of themselves, right? I did check all the linkage, using my calipers I checked the measurements between said linkages and compared them to the specs listed in the service manual.


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## Smackdaddy53 (Dec 31, 2012)

NativeBone said:


> UPDATE: So far the motor idles as designed and has not repeated the unusual high idle it once did. So what should I look for? My experience tells me this will ultimately happen again. Problems rarely take care of themselves, right? I did check all the linkage, using my calipers I checked the measurements between said linkages and compared them to the specs listed in the service manual.


Read the second half of post #10

There is a procedure to test the prime start system and the needle for movement. It was post on another recent thread about yamaha idle issues.


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## NativeBone (Aug 16, 2017)

Smackdaddy53 said:


> Read the second half of post #10
> 
> There is a procedure to test the prime start system and the needle for movement. It was post on another recent thread about yamaha idle issues.


Got it! Thanks


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