Yamaha 4 stroke timing

Quadcab

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Joined
Nov 30, 2019
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Any help here would be greatly appreciated. I recently replaced my Yamaha 2010 90hp 4 stroke outboard's timing belt. First, I aligned the crank and cam marks as noted in the manual, remove the flywheel, stator, brackets and tensioner. I used cable ties to keep the cam marks from moving. After putting everything back together, I started the motor and it would only run at increased throttle. I removed the spark plugs and turned the engine by hand only to see that my timing marks on the cams are off by 2-3 teeth (see pics). I guess something move when I put the new belt on. My question is if I align the crank timing mark back up and manually try to turn the cam marks up the way that they're suppose to be, will I be doing more hurt than harm or should that solve my problem?
 

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Quadcab

Recruit
Joined
Nov 30, 2019
Messages
3
Any help here would be greatly appreciated. I recently replaced my Yamaha 2010 90hp 4 stroke outboard's timing belt. First, I aligned the crank and cam marks as noted in the manual, remove the flywheel, stator, brackets and tensioner. I used cable ties to keep the cam marks from moving. After putting everything back together, I started the motor and it would only run at increased throttle. I removed the spark plugs and turned the engine by hand only to see that my timing marks on the cams are off by 2-3 teeth (see pics). I guess something move when I put the new belt on. My question is if I align the crank timing mark back up and manually try to turn the cam marks up the way that they're suppose to be, will I be doing more hurt than harm or should that solve my problem?
Just wanted to provide an update in case this happens anyone. I took everything back off and except the timing belt. I lined the crank to it's mark and took off the timing belt. Since the cam marks were only off by a 2-3 teeth, I manually lined the cam marks by hand and put the timing belt back on. After turning everything over by hand, everything lined up perfectly and the motor runs great. WHEW!!!!
 

Quadcab

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Nov 30, 2019
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Attached is what your timing marks should look like if you have marks lined up correctly. Note the marks that I have circled. If you have these lined up EXACTLY, you won't have any problems.
 

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ncfishhawk

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Joined
Apr 29, 2013
Messages
17
Attached is what your timing marks should look like if you have marks lined up correctly. Note the marks that I have circled. If you have these lined up EXACTLY, you won't have any problems.
does the hole in the plate lined up over the cast mark on the block also equate to TDC?
 
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