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1987 Yamaha 9.9 4 Stroke issue

M

mobiletec

Member
Hello everyone. I Have a Yamnaha F9.9 SH- 1987 4 stroke that i have rebuilt the carb and am having an issue with. Now this issue was present even before rebuild so iam assumming the issue is something else. Starts first pull -Idle comes up high till it warms up. Then it comes down to idle great and idle perfectly. Put it in gear and its fine. Throtle up but i cant get full throtle seems as its holding back. doesn`t stall out or anything just wont ramp up to full throtle. I checked the plugs replaced them. Linkages are got cable from tiller is good. could someone maybe kick in and give me some advice as to probable causes. OHH also how do you check and adjust timming on these motors. Thanks in advance
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With the carb airbox removed, choke open with the engine in forward gear - when you turn the handle wide open does the throttle plate open to maximum open position? If not adjust the rod/cable so it does.
 
Timing rarely goes out of adjustment on an outboard !!!-------------My suggestion is to revisit cleaning of the carburetor !!
 
Thanks for the sugestions I have installed a new carb kit only because of opening up the carb severl times . the carb is spotless and all passages are blown through. I seems very rich when throtled above min trolling speed . Just seems that too much fuel is entering the engine. Could a weak coil or CDI have enough spark to hold the motor at idle and just above,But spark becomes weak above that? Thank for the help:)
racerone said:
Timing rarely goes out of adjustment on an outboard !!!-------------My suggestion is to revisit cleaning of the carburetor !!
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