The motor is a 2000 Yamaha 70hp. it is a 2 stroke motor. The motor cranks fine, but then when I go to accelerate it shuts off. I can go at idle speed all day long with no problem. But as soon as the throttle goes forward and the boat starts to get on plane then the motor shuts off.
any thoughts?
also, where is a good place in charleston area that does work on yamaha motors?
sounds like a carb issue to me
there are a lot of good Yamaha shops in Charleston, including us at Charleston Marine
I would never disregard any advice from chris V, the man seems to get a ton of respect from the members of this site and without a doubt knows a heck of a lot more about boat motors than I do. However, I have the same 2000 70 Yamaha two stroke on my Key West.(been a great motor btw)A couple of weeks after I bought the boat it started exhibiting the very same symptoms you’ve described. Turned out the cap on the fuel/water separator/filter had worked itself loose and the seal was compromised. I tightened the cap and the boat ran fine for a week or two then started doing the same thing, sure enough the cap had come loose again. Tightened the cap, boat ran fine, happened again, this time I used a four" rubber pipe collar and a couple of hose clamps to make sure the cap stayed tight till I could replace it and its run great ever since, that was 3 years ago. May not be your problem but it takes five minutes to check and it was a 3 dollar fix that took 30 minutes including the trip to Lowes to purchase the collar and clamps. Good luck.
Key West 1520
70 Yami
She’s little, but she’s pretty, skinny and fast.
Ditto on Chris’s advice. I also have a Yammy 70 and had the same problem. Mine turned out to be the small filter on the motor. It had worked its way loose and would run at idle but not when I tried to accelerate. Once I tightened it up, problem solved. Check these things and if that does not fix it then go see Chris.
“Apathy is the Glove in Which Evil Slips It’s Hand”.
usually if you have a situation where the fuel system is sucking air, the motor wont run perfect at idle only, it will run great at all speeds right after you pump the primer bulb, for a few seconds, then it will shut off completely.
also, if you have a leak like the other guys are describing, the primer bulb will never get firm, but the suggestions are easy to check, and stranger things have happened.
I agree with Chris, sounds like a carb issue or the cabs are opening before your timing is advancing. Would be the first two things i would check.