9.9 Yamaha HT won’t idle low

pescador

Well-Known Member
My 150 hour 2020 Yamaha 9.9 was serviced and winterized by the dealer in Victoria in Oct of last year. It ran perfect at the end of the year. When I tried to start it today in preparation for my first Nootka trip in July, it wouldn’t start. I pumped the bulb to ensure it had gas. After a while I decided I’d push then throttle all the way down. It starts. Problem is it won’t idle down. It wants throttle. It’s always idled low perfect. Any ideas? I think it might be under warranty but if it’s a simple thing I’d fix myself.
 
Is it fuel injected? If it is, maybe it’s the IAC?
My T25 has had 2, in 2 years.
Good call or it could be as easy as a ring has formed in the throttle body. A scotch Brite pad and clean it off
 
My 150 hour 2020 Yamaha 9.9 was serviced and winterized by the dealer in Victoria in Oct of last year. It ran perfect at the end of the year. When I tried to start it today in preparation for my first Nootka trip in July, it wouldn’t start. I pumped the bulb to ensure it had gas. After a while I decided I’d push then throttle all the way down. It starts. Problem is it won’t idle down. It wants throttle. It’s always idled low perfect. Any ideas? I think it might be under warranty but if it’s a simple thing I’d fix myself.

If it has carburetor , jet, jets, jets, remove and clean them out, very simple job,
 
was there fuel left in the carb over the winter? or did you run it dry/ drain the bowl?
 
All yam 9.9‘s are still carb’d. I’ve called the dealer. They say it needs the carb cleaned. Booked in. Its Under warranty. Never ever had this issue with the Yam HT8 I had on the boat for 13 years before I swapped out for this one. Thanks for all the replies. They recommend a carb cleaning every 2 years. Thanks for all responses guys.
 
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my 9.9 goes through the same song and dance every year, ran it dry with premium fuel with stabilizer in the fuel at the end of the season and still the same issue.You are going to have to pull the carb and clean it.the idle jet is so small that just a tiny bit of anything will clog it.
 
my 9.9 goes through the same song and dance every year, ran it dry with premium fuel with stabilizer in the fuel at the end of the season and still the same issue.You are going to have to pull the carb and clean it.the idle jet is so small that just a tiny bit of anything will clog it.
One of the best small engine mechanic told me not to run them dry( goes for any small engine) premium gas with stabilizer, let it run for a bit to get fuel in the carb then just leave it, catch 22 is never more then 2-3 months without running, been doing that on all my small engine and seems to work,lot less carb work since for me
 
I don't run mine dry but do add Stabilzer over winter and avoid any fuel with ethanol like the plague. It separates over time, forms into a Gel and clogs any carb up...the smaller the jets the worse and faster it happens.
 
Well. Sherwood disconnected the fuel line when they winterized it in Oct and I assume ran the carb dry. Next time I went to start it it didn’t start. Not sure running it dry is the answer
 
My Yamaha 8 hp hi thrust ran perfectly until last year, wouldn’t start in the spring had carb cleaned out it ran but stalled at low speed then wouldn’t start unless throttle was wide open and gobbled fuel. Fiddled with carb some more still doesn’t run right seems to be flooding in my opinion. Now it actually runs pretty good with the low speed jet turned right in which doesn’t make any sense. Any ideas anyone?
 
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