Yamnha 3 cyl 25 2stroke shuttering at high rpms??

General Boats and Motors
1

Yesterday while coming in from fishing, I went to WOT and it started shuttering and not gaining RPMS…Kinda acted like it does when you have weeds on the prop. (There were no weeds btw). I had been cruising all day at 0-3/4 throttle and there were no problems in acceleration or anything at all. The issue only came about after 3/4 + throttle. Once I backed off a little everything was smooth again.

Thoughts?

Dirty carb in third cylinder? Do these motors run on two cylinders and when opened up kick in the third?

Thanks.

2

They run 3 cylinders all the time. Probably a dirty spark plug

Key West 2300cc Mercury 225 optimax “Fish Tale”

3

decarb the motor through the fuel system
change the plugs
test run

www.teamcharlestonmarine.com
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4

Chris… What is your preferred decarbing method and brand that you recommend?